CA1148741A - Method and apparatus for retaining heat in greenhouse and similar structures - Google Patents
Method and apparatus for retaining heat in greenhouse and similar structuresInfo
- Publication number
- CA1148741A CA1148741A CA000357144A CA357144A CA1148741A CA 1148741 A CA1148741 A CA 1148741A CA 000357144 A CA000357144 A CA 000357144A CA 357144 A CA357144 A CA 357144A CA 1148741 A CA1148741 A CA 1148741A
- Authority
- CA
- Canada
- Prior art keywords
- greenhouse
- blanket
- insulating
- insulating blanket
- covering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title description 2
- 239000012528 membrane Substances 0.000 claims abstract description 18
- 238000009833 condensation Methods 0.000 claims abstract description 4
- 230000005494 condensation Effects 0.000 claims abstract description 4
- 238000009413 insulation Methods 0.000 claims description 70
- 238000003860 storage Methods 0.000 claims description 33
- -1 polyethylene Polymers 0.000 claims description 20
- 239000004698 Polyethylene Substances 0.000 claims description 18
- 239000000463 material Substances 0.000 claims description 18
- 229920000573 polyethylene Polymers 0.000 claims description 17
- 239000002184 metal Substances 0.000 claims description 10
- 239000011521 glass Substances 0.000 claims description 9
- 238000004804 winding Methods 0.000 claims description 8
- 229920003023 plastic Polymers 0.000 claims description 7
- 239000003365 glass fiber Substances 0.000 claims description 5
- 230000033001 locomotion Effects 0.000 claims description 5
- 239000011810 insulating material Substances 0.000 claims description 4
- 239000004033 plastic Substances 0.000 claims description 4
- 230000004044 response Effects 0.000 claims description 4
- 239000002985 plastic film Substances 0.000 claims description 3
- 230000000284 resting effect Effects 0.000 claims description 3
- 229920002554 vinyl polymer Polymers 0.000 claims description 3
- 238000007789 sealing Methods 0.000 claims description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 description 9
- 239000004744 fabric Substances 0.000 description 7
- 239000000446 fuel Substances 0.000 description 6
- 230000008901 benefit Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000008187 granular material Substances 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 241000196324 Embryophyta Species 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000008014 freezing Effects 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 230000009182 swimming Effects 0.000 description 2
- 235000007689 Borago officinalis Nutrition 0.000 description 1
- 240000004355 Borago officinalis Species 0.000 description 1
- 241000282596 Hylobatidae Species 0.000 description 1
- 238000007202 Nickl synthesis reaction Methods 0.000 description 1
- 230000035508 accumulation Effects 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000002844 continuous effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 230000003334 potential effect Effects 0.000 description 1
- 230000010349 pulsation Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
- A01G9/14—Greenhouses
- A01G9/1469—Greenhouses with double or multiple walls
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
- A01G9/22—Shades or blinds for greenhouses, or the like
- A01G9/227—Shades or blinds for greenhouses, or the like rolled up during non-use
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
- Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
- Y02A40/25—Greenhouse technology, e.g. cooling systems therefor
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Environmental Sciences (AREA)
- Greenhouses (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An improved building, e.g., a greenhouse structure, is provided herein. It consists of an enclosure having a pair of spaced-apart walls, e.g., an outer light transparent covering and an inner light transparent membrane spaced apart from the outer covering. A fan is provided for charging the space between the covering and the membrane with air, having a dew point so selected that it will not allow condensation to take place, e.g., outdoor air, under pressure. An insulating layer is disposed in the pressurized air space between the outer covering and the inner membrane.
The insulating layer includes an insulating blanket disposed between the outer covering and the inner membrane, and is positively movable between an extended covering position and a retracted stored position. Operating structure is connected to a leading edge of the blanket and this structure is adapted to move the leading edge from its retracted stored position to its extended covering position. Cooperative structure is provided opera-tively associated with the trailing portion of the blanket. This struc-ture is adapted to draw the blanket from its extended covering position to its retracted stored position. This provides a system in which heat loss from within the structure is minimized at night and yet does not result in excessive condensation within the structure.
An improved building, e.g., a greenhouse structure, is provided herein. It consists of an enclosure having a pair of spaced-apart walls, e.g., an outer light transparent covering and an inner light transparent membrane spaced apart from the outer covering. A fan is provided for charging the space between the covering and the membrane with air, having a dew point so selected that it will not allow condensation to take place, e.g., outdoor air, under pressure. An insulating layer is disposed in the pressurized air space between the outer covering and the inner membrane.
The insulating layer includes an insulating blanket disposed between the outer covering and the inner membrane, and is positively movable between an extended covering position and a retracted stored position. Operating structure is connected to a leading edge of the blanket and this structure is adapted to move the leading edge from its retracted stored position to its extended covering position. Cooperative structure is provided opera-tively associated with the trailing portion of the blanket. This struc-ture is adapted to draw the blanket from its extended covering position to its retracted stored position. This provides a system in which heat loss from within the structure is minimized at night and yet does not result in excessive condensation within the structure.
Description
8~1 This invention relates to systems for minimizing heat loss from buildings. More particularly, it is directed to systems for selectively insulating large transparent exterior walls, e.g., the roofs and walls of greenhouses and other structures, e.g., swimming pool covers.
There are in the United States and Canada commercial greenhouses totalling over 250 million square feet. Over two-thirds of this total is in the northern United States and Canada, where greenhouses must be heated during at least some of the year. The greenhouse heating cost exceeds $120 million annually.
Most of the fuel used to heat greenhouses is expended at night.
It is thought that night-time heating accounts for as much as 80% of the total heating bill. Recent increases in fuel cost, coupled with severe shortages of fuels, have faced greenhouse owners with a major problem.
They must cut their total fuel consumption drastically if they wish to remain competitively viable.
The energy requirements of commercial greenhouses for heating are so high at present as to exclude economic operation of many green-houses. One way to cut fuel consumption is to reduce the hèat loss through the greenhouse walls and roof, especially at night. Insulating the walls or roof can significantly reduce heating requirements, but itself presents several potentially serious problem~. An insulating system should not significaatly reduce the amount of sunlight that can -enter the house during the day. The insulating system may take up valuable growing space within the greenhouse. North walls and part of roofs have been insulated, but these reduce effective growing area ana the production per plant because of poor light, to the point where the structure is not economic. The radiant heat loss at night can be minimized by using cloth or polyethylene-screens inside the-structure and these h~e-been--attempted.-They fail in cold climates (i.e., below -18C.) because the moisture-laden ' - 1- 3~
-:
!
~1~8741 air creeps around the screèn and forms frost on the inside cover of the greenhouse. Often this falls off when the sun warms the roof and walls, thereby damaging the plants as well as creating a hazard for workers. If it does not, the resulting chill from the cold air sbove the screen reduces the crop yield significantly (e.g., 10 to 15%). Outside shutters have also been tried but wind problems and economics exclude this type of arrange- -ment in commercial greenhouses, although feasible in back yard greenhouses.
Accordingly, an insulating system should be readily adaptable for use with greenhouses of widely varying size and construction, and should cover a large area rather than requiring many small systems installed between each pair of obstructing greenhouse supports.
Many systems have been proposed to control the temperature within greenhouses. Thus, French Patent No. 371,926 dated March 19, 1907 provides a system in which shades are provided which can be rolled up or down the exterior arched transparent walls of greenhouse structures.
Italian Patent No. 695,829 dated September 27, 1965 provides a system in which shades are drawn within the inside of the greenhouse structure, the shades being in the form of a movable horizontal ceiling.
Italian Patent No. 717,643 dated October 15, 1966 provides a system in which shades are drawn across the transparent portion of the greenhouse parallel to the sloping roof thereof to provide an internal, dropped shielding ceiling.
Canadian Patent No. 982,426 issued January 27, 1976 to R. Delano et al provides a method of protecting greenhouses involving coating the inside transparent surfaces of the greenhouses with a coating which is translucent, so that the amount of light permitted therethrough is con-trolled by the thickness and density of the coating and which, when wet, becomes almost transparent, permitting the passage of considerably more light therethrough than when dry. The humidity of the interior of the
There are in the United States and Canada commercial greenhouses totalling over 250 million square feet. Over two-thirds of this total is in the northern United States and Canada, where greenhouses must be heated during at least some of the year. The greenhouse heating cost exceeds $120 million annually.
Most of the fuel used to heat greenhouses is expended at night.
It is thought that night-time heating accounts for as much as 80% of the total heating bill. Recent increases in fuel cost, coupled with severe shortages of fuels, have faced greenhouse owners with a major problem.
They must cut their total fuel consumption drastically if they wish to remain competitively viable.
The energy requirements of commercial greenhouses for heating are so high at present as to exclude economic operation of many green-houses. One way to cut fuel consumption is to reduce the hèat loss through the greenhouse walls and roof, especially at night. Insulating the walls or roof can significantly reduce heating requirements, but itself presents several potentially serious problem~. An insulating system should not significaatly reduce the amount of sunlight that can -enter the house during the day. The insulating system may take up valuable growing space within the greenhouse. North walls and part of roofs have been insulated, but these reduce effective growing area ana the production per plant because of poor light, to the point where the structure is not economic. The radiant heat loss at night can be minimized by using cloth or polyethylene-screens inside the-structure and these h~e-been--attempted.-They fail in cold climates (i.e., below -18C.) because the moisture-laden ' - 1- 3~
-:
!
~1~8741 air creeps around the screèn and forms frost on the inside cover of the greenhouse. Often this falls off when the sun warms the roof and walls, thereby damaging the plants as well as creating a hazard for workers. If it does not, the resulting chill from the cold air sbove the screen reduces the crop yield significantly (e.g., 10 to 15%). Outside shutters have also been tried but wind problems and economics exclude this type of arrange- -ment in commercial greenhouses, although feasible in back yard greenhouses.
Accordingly, an insulating system should be readily adaptable for use with greenhouses of widely varying size and construction, and should cover a large area rather than requiring many small systems installed between each pair of obstructing greenhouse supports.
Many systems have been proposed to control the temperature within greenhouses. Thus, French Patent No. 371,926 dated March 19, 1907 provides a system in which shades are provided which can be rolled up or down the exterior arched transparent walls of greenhouse structures.
Italian Patent No. 695,829 dated September 27, 1965 provides a system in which shades are drawn within the inside of the greenhouse structure, the shades being in the form of a movable horizontal ceiling.
Italian Patent No. 717,643 dated October 15, 1966 provides a system in which shades are drawn across the transparent portion of the greenhouse parallel to the sloping roof thereof to provide an internal, dropped shielding ceiling.
Canadian Patent No. 982,426 issued January 27, 1976 to R. Delano et al provides a method of protecting greenhouses involving coating the inside transparent surfaces of the greenhouses with a coating which is translucent, so that the amount of light permitted therethrough is con-trolled by the thickness and density of the coating and which, when wet, becomes almost transparent, permitting the passage of considerably more light therethrough than when dry. The humidity of the interior of the
- 2 -.
- : .' ' ' 11~8741 greenhouse, which was alleged to vary from high on cloudy days to low on sunny days, was said automatically to control the amount of light entering the greenhouse.
Canadian Patent No. 1,003,641 issued January 18, 1977 to H.
Grossman et al provided a shade-providing system incluaing at least one powered track on which a drape or shade cloth was supported for covering an area. The powered track included a self-contained motor means having a track guiding means for drawing the shade cloth between a gathered stored position and to an extended position for shading a selective area.
10 The shade system could also include suspension tracks spaced from the powered track means for maintaining the shade cloth or panel elevated above the benches. The suspension tracks were said to be devoid of any actuating means and served merely as a support and guide for the shade cloth.
United States Patent No. 4,064,648 issued December 27, 1977 to C. L. Cary provided an insulating system for reducing heat loss from a structure during one part of the day and for permitting light to enter the structure during another part of the day This system included a roll mounted within the structure, a flexible sheet of material wound around 20 the roll, a structure for supporting the roll immediate its length and engaging portions of the wound sheet, and means both for unwinding the sheet from the roll and deploying it in a plane and for rotating the roll to rewind the sheet therearound.
Canadian Patent i~o. 1,043,070 issued November 28, 1978 to M. Dube provided a system of filling double-glazed building panels with insulating light-weight granular material for the purpose of providing insulating shading or privacy and for evacuating such material therefrom when light -~ transmission wasq~o_be restored~. The system included alcontainer~for the ~ material, a header for through-flow of gas-conveyed granular material into ,".
, ' 87~1 and from the space between the double-gIazed unit, and blower means and controls therefor for conveying the granular material into the space and for retaining it therein by gaseous pressure.
United States Patent No. 4,067,347 issued January 10, 1978 to Lipinski provided a portable solar-heated shelter comprising at least one fixed roof layer and a second mechanically supported roof layer which cJn be selectively deployed to v~ry the thermal characteristics of the shelter. The second roof layer was adapted to be unwound from a storage spool and drawn into a take-up spool, passing over the first roof layer, by a cranking action. The second roof layer included a first sunshade portion and a series connected heat insulative portion of opaque material which may be selectively deployed to control the thermal characteristics of the enclosure.
Canadian Patent ~o. 1,054,081 issued May 8, 1979 to D.M. Fraioll provided a double wall fabric panel unit supported by pressurized air pumped into the interior thereof, with insulation provided in the double walled panels by including a plastic coated fabric panel and a thermal liner panel, with side edge strips being discontinuous tG provide spaced air passageways to vent air from between the panels as the unit is rolled.
Other attempted solutions to the problems outlined above are believed to be provided in the following additional patent literature.
United States Patent Documents - 1,056,120 3/1913 Poindexter 1,100,598 6/1914 McLaren et al 1,284,978 11/1918 Axe 1,718,215 6/1929 Burrage 2,046,600 7/1936 Atkinson 2,182,852 12/1939 Mulford 2,193,921 3/1940 Gibbons '' :
874~ , 1.
United States Patent Documents (continued) 2,220,311 11/1940 Anton .
2,248,414 7/1941 Schane 2,660,659 11~1953 Sarno 2,787,695 4/1957 Dyke 2,922,183 1/1960 Taylor
- : .' ' ' 11~8741 greenhouse, which was alleged to vary from high on cloudy days to low on sunny days, was said automatically to control the amount of light entering the greenhouse.
Canadian Patent No. 1,003,641 issued January 18, 1977 to H.
Grossman et al provided a shade-providing system incluaing at least one powered track on which a drape or shade cloth was supported for covering an area. The powered track included a self-contained motor means having a track guiding means for drawing the shade cloth between a gathered stored position and to an extended position for shading a selective area.
10 The shade system could also include suspension tracks spaced from the powered track means for maintaining the shade cloth or panel elevated above the benches. The suspension tracks were said to be devoid of any actuating means and served merely as a support and guide for the shade cloth.
United States Patent No. 4,064,648 issued December 27, 1977 to C. L. Cary provided an insulating system for reducing heat loss from a structure during one part of the day and for permitting light to enter the structure during another part of the day This system included a roll mounted within the structure, a flexible sheet of material wound around 20 the roll, a structure for supporting the roll immediate its length and engaging portions of the wound sheet, and means both for unwinding the sheet from the roll and deploying it in a plane and for rotating the roll to rewind the sheet therearound.
Canadian Patent i~o. 1,043,070 issued November 28, 1978 to M. Dube provided a system of filling double-glazed building panels with insulating light-weight granular material for the purpose of providing insulating shading or privacy and for evacuating such material therefrom when light -~ transmission wasq~o_be restored~. The system included alcontainer~for the ~ material, a header for through-flow of gas-conveyed granular material into ,".
, ' 87~1 and from the space between the double-gIazed unit, and blower means and controls therefor for conveying the granular material into the space and for retaining it therein by gaseous pressure.
United States Patent No. 4,067,347 issued January 10, 1978 to Lipinski provided a portable solar-heated shelter comprising at least one fixed roof layer and a second mechanically supported roof layer which cJn be selectively deployed to v~ry the thermal characteristics of the shelter. The second roof layer was adapted to be unwound from a storage spool and drawn into a take-up spool, passing over the first roof layer, by a cranking action. The second roof layer included a first sunshade portion and a series connected heat insulative portion of opaque material which may be selectively deployed to control the thermal characteristics of the enclosure.
Canadian Patent ~o. 1,054,081 issued May 8, 1979 to D.M. Fraioll provided a double wall fabric panel unit supported by pressurized air pumped into the interior thereof, with insulation provided in the double walled panels by including a plastic coated fabric panel and a thermal liner panel, with side edge strips being discontinuous tG provide spaced air passageways to vent air from between the panels as the unit is rolled.
Other attempted solutions to the problems outlined above are believed to be provided in the following additional patent literature.
United States Patent Documents - 1,056,120 3/1913 Poindexter 1,100,598 6/1914 McLaren et al 1,284,978 11/1918 Axe 1,718,215 6/1929 Burrage 2,046,600 7/1936 Atkinson 2,182,852 12/1939 Mulford 2,193,921 3/1940 Gibbons '' :
874~ , 1.
United States Patent Documents (continued) 2,220,311 11/1940 Anton .
2,248,414 7/1941 Schane 2,660,659 11~1953 Sarno 2,787,695 4/1957 Dyke 2,922,183 1/1960 Taylor
3,140,857 7/1964 Nickles 3,193,637 711965 Russell 3,309,473 3/1967 Heinrich 10 3,315,727 4/1967 Clark 3,418,752 12/1968 Stratton ~,350,192 611969 Hay ~ .
3,460,602 8/1969 Hugus 3,481,073 12/1969 Yoshida et al 3,493,032 2/1970 Brown, Jr. et al 3,568,588 3/1971 Kudeck 3,581,884 6/1971 Caldwell 3,656,782 3/1972 Molino 3,765,134 10/1973 Gilchrist 20 3,791,076 2/1974 Gahler 3,900,063 8/1975 Roller Other Patent Documents 563,865 3/1923 France .
1,211,764 4/1902 France 172,275 3/1905 Germany 408,463 1/1925 Germany 2,363,825 12/1973 Germany 1,911,3~Q1~ 6/1969 Germany 1,952,639 5/1971 Germany _ 5 _ .
~1~8741 Other Patent Documents (continued) 645,306 5/1948 United Kingdom 1,113,577 5/1968 United Kingdom 1,385,261 211975 United Kingdom.
While the teachings of United States Patents ~os. 4,067,347 (Lipinski) and 4,064,648 (Cary), described above. provided a movable insulation to allow entrance of light in day and provide insulation at night, the Lipinski and Cary approaches are uneconomical because of their complexity and have one basic failing, namely, that they do not protect against formation of frost or ice within the structure but outside of the insulating layer.
Moreover, Cary does not provide a movable insulation outside the usable space. The system taught by Cary is very difficult and expen-sive to install. Installed within a greenhouse, it will be extremely difficult to overcome the infiltration of warm, moist air above the flexible material at night which will freeze on the mechanism or the roof.
In cold climates (e.g., as in Canada and the northern United States), this system will not prevent the freezing problem, and in addition, it will create a cold mass of air above the blanket that will fall once the ~20 blanket is withdrawn, and result in chilling that will impede the growth of greenhouse crops. Cary attempts to overcome the icing and snow accumu-lation on the outside of the roof by automatically retracting the blanket.
Lipinski provides for the placement of the insulating barrier between unpressurized flexible roof layers. The system, however, will fail in cold freezlng climates sioce any small hole (either accidental or otherwise) will allow the warm moist air to penetrate into the space between his roofs, freeze onto the mechanism, tear the walls and immobilize the blanket. Its very nature only allows it to be used on structures of short length, i.e., movable shelters.
.
11~87~
Accordingly, an ob~ect of a broad aspect of this invention is to provide a system which has great economic significance for the greenhouse industry, is practical, economical and immediately usable.
An object of another aspect of this invention is to provide such a system which is simple and hence which has a very higX potential in the market place for all countries with cold climates.
An object of yet another aspect of this invention is to provide such a system which includes an automatic retraction device.
An object of still another aspect of this invention is to provide such a system whereby snow on the greenhouse is caused to melt or fall off naturally by retracting the blanket and by inflation and/or mechanical pulsations.
By one broad aspect of this invention, a structure is provided comprising an enclosure having an outer light-transparent wall and an inner light-transparent wall spaced apart from that outer wall, means for charging the space between the outer wall and the inner wall with air having a dew point so selected that it will not allow condensation to take placé under pressure, and an insulating layer disposed in the pressurized air space between the outer wall and the inner wall and comprising: (a) an insulating blanket disposed in the pressurized air space between the Outer wall and the inner wall and movable between an extended covering position and a retracted stored position within an enclosed storage area;
(b) means connected to a leading edge of the insulating blanket and positively operable to move the leading edge from its retracted stored position to its extended covering position; and (c) means operatively associated with the trailing portion of the insulating blanket and adapted to draw the insulating blanket from its extended covering position to its ret~e~ed stored position. -- - ¦
By one variant of this invention, the presssurized air space .
: ~ ;: ' , 11g~8741 may be disposed only in a horizontal or approximately horizontal position, in which case the insulating blanket is drawn across the horizontal area by carrier cables from an accordion-folded retracted stored position to an extended covering position, and vice versa, and with the leading edge at any selected position between extended and retracted:
By one variation thereof, the horizontal-type situation would be, for example, on a gutter-connected, pillow-type open greenhouse.
By another variant, the greenhouse of the gutter-connected pillow- type, open-type includes a roof of a plurality of inflated double-walled polyethylene pillows.
By another variant thereof, the insulating blanket is supportedat spaced-apart locations throughout its length by carrier cables, the carrier cables being movable in both directions under constant tension to extend or to retract the insulation blanket.
Another aspect of this invention is provided where the insula-ting blanket is drawn across a roof structure when it is disposed in a metal arch gutter-connected greenhouse. By a variant thereof, the insula-ting blanket would move in a generally one-half sinusoidal path.
By yet another variant, the greenhouse of the metal arch gutter-connected type includes an inner transparent layer of polyethyleneresting on the metal arched frames and separated from the outer polyethy-lene arch by the outside air under pressure.
By a variation thereof, the insulating blanket is supported by three longitudinally extending cables, which are under tension to enable movement of the blanket, but which, when relaxed, allow the insulating blanket to rest on the inner polyethylene layer to provide the covering insulatiD~ .
By a further variant-thereof,-~the=blanket-~s provided with -carrier cables, the carrier cables being movable transverse of and within , .
~1~874~
the arches in both directions under constant tension to extend or to retract the insulation blanket.
According to another aspect of this invention, if the greenhouse is a steep roof type or quonset hut type, the trailing edge is provided with a ballast weight or tension device, e.g., an electric tension cord to draw the blanket into a lower storage box. The storage box may or may not be insulated.
According to a further aspect of this invention, if the green-house is of the flat roof type, the insulating blanket is controlled by a two-rope constant-tension system. The insulation may be one extensive width or be of a plurality of butted batts of insulating blankets.
By another variant of this invention, the greenhouse if of the very flat roof hoop-type, and includes a plurality of such butted batts of insulation blankets, with extension and retraction being accomplished by a rope secured at one end to the leading edge of the insulation blanket and at its other end wrapped in one direction on a rotatable shaft, and a second rope wrapped in an opposite direction to the rotatable shaft and trained around a lower pulley and secured to a lower pull bar on the insulation blanket.
By yet another variant, in a very flat roof type greenhouse, a pair of rollers are provided engaging opposite faces of the insulation blanket to hold the insulation blanket to the vertical wall.
By yet another variant, the greenhouse is of the quonset hut type and the extension and retraction of the insulation blanket is accom-plished by a continuous rope, entraining a plurality of pulleys within the greenhouse, wound around a rotatable winding shaft and each end con-nected to the leading edge of the insulation blanket.
By another variant, the means (b) comprises a motor manually actuatable to move the insulating blanket to a selected position between ~'' _ g _ ~L~48741 its extended covering position and its retracted stored position, and to hold the blanket at that selected position.
: By another variant, the means tb) comprises a motor automatically actuatable in response to a preselected cycle automatically to move the insulating blanket in response to predetermined positions of the sun with respect to the greenhouse.
By a further variant thereofl one longitudinal half of the greenhouse has its insulating blanket in its extended covering position while the other longitudinal half of the greenhouse has its insulating blanket in its retracted stored position.
By another variant, one longitudinal half of the greenhouse has its insulating blanket movable between its extended covering position to its retracted stored position, while the other longitudinal half of the greenhouse has its insulating blanket movable between its retracted stored position and its extended covering position.
By a further variant, the greenhouse is of the hoop-type and includes an arched framework, an outer light-transparent covering there-over, a spaced-apart, inner, light-transparent membrane thereover, and fan means for inflating the space between the outer covering and the inner me~brane with outside air.
By yet another variant, the fan means introduces air into one of the storage boxes or above the boxes, or at any other convenient location.
By still another variant, the fan means introduces air into a header disposed at the apex crest of the arched structure, between the outer covering and the inner membrane.
By yet another variant of such greenhouse, the outer covering and the inner membrane each comprise a polyethylene sheet.
By_aDother aspect.of this invention, the greenhouse is of the rigid transparent, e.g., glass-type, and includes a rigid roof and wall system of rigid transparent, e.g., glass plates and an outer skin of flexible transparent plastic sheet disposed in spaced-apart relation from the rigid transparent, e.g., glass plates between the base of the struc-ture and the apex of the roof thereof, and includes fan means for intro-ducing the outside air under pressure between the rigid transparent, e.g., glass plates and the transparent skin to provide a double walled unit.
By another variant, the rigid transparent plates are, e.g., flat or corrugated sheet material made of glass fibers.
By another variant thereof?the fan means pressurizes the space of the storage boxes or above the boxes or at any other convenient loca-tion under conditions of zero or approaching zero flow, in order to mini-mize heat transfer and minimize fan power.
By another variant, the insulating blanket includes a pair of sealing skins with a filling of insulating material therebetween.
By a further variant thereof, one skin is formed of a pliable waterproof material, e.g., polyethylene or polyvinyl plastic.
By another variant, one skin is formed of an aluminized material.
By a further variant, the filling of insulating material is formed of a structurally integral glass fiber blanket.
By yet another variant, the insulating blanket includes a further portion comprising a mesh material to provide shading to restrict the amount of light entering the greenhouse.
Accordingly, this invention in its broad aspect addresses itself to several critical problems, namely, reduction of light by north wall insulation, the formation of ice on the structure covering and morning chill of crop, and wind problems and the economics, and substantially over-comes such problems by a movable layer of flexible insulation placed between~-the two spaced-apart walls of the greenhouse which are charged ~_~___ with pressurized air, depending on light and temperature conditions, to :.
il~874~ i minimize heating requirements. The inside cover of the insulation is pre-fersbly covered with a light-reflecting material, e.g., reinforced aluminized material, to enhance light conditions when partially covered.
The provision of the pressurized zone of gas between the outer and inner walls has the following advantages: ¦
(1) It substantially eliminates any freezing problem in the space containing the insulation since outdoor air entering into the struc-ture is dry and substantially prevents moisture penetration into the space from the interior.
(2) Because of the pressurization, a space is provided which is free of structure, that easily accommodates thick or thin insulation (up to 3" or more in thickness) and provides a space for a suitable windup mechanism. It can accommodate any length of greenhouse. The standard 100' greenhouse could thus use two 50' systems or any number of smaller sized modular systems.
(3) The complicated storage device is eliminated. In one embodiment, the insulation folds under the action of gravity, which effec-tively eliminates the lower roller.
3,460,602 8/1969 Hugus 3,481,073 12/1969 Yoshida et al 3,493,032 2/1970 Brown, Jr. et al 3,568,588 3/1971 Kudeck 3,581,884 6/1971 Caldwell 3,656,782 3/1972 Molino 3,765,134 10/1973 Gilchrist 20 3,791,076 2/1974 Gahler 3,900,063 8/1975 Roller Other Patent Documents 563,865 3/1923 France .
1,211,764 4/1902 France 172,275 3/1905 Germany 408,463 1/1925 Germany 2,363,825 12/1973 Germany 1,911,3~Q1~ 6/1969 Germany 1,952,639 5/1971 Germany _ 5 _ .
~1~8741 Other Patent Documents (continued) 645,306 5/1948 United Kingdom 1,113,577 5/1968 United Kingdom 1,385,261 211975 United Kingdom.
While the teachings of United States Patents ~os. 4,067,347 (Lipinski) and 4,064,648 (Cary), described above. provided a movable insulation to allow entrance of light in day and provide insulation at night, the Lipinski and Cary approaches are uneconomical because of their complexity and have one basic failing, namely, that they do not protect against formation of frost or ice within the structure but outside of the insulating layer.
Moreover, Cary does not provide a movable insulation outside the usable space. The system taught by Cary is very difficult and expen-sive to install. Installed within a greenhouse, it will be extremely difficult to overcome the infiltration of warm, moist air above the flexible material at night which will freeze on the mechanism or the roof.
In cold climates (e.g., as in Canada and the northern United States), this system will not prevent the freezing problem, and in addition, it will create a cold mass of air above the blanket that will fall once the ~20 blanket is withdrawn, and result in chilling that will impede the growth of greenhouse crops. Cary attempts to overcome the icing and snow accumu-lation on the outside of the roof by automatically retracting the blanket.
Lipinski provides for the placement of the insulating barrier between unpressurized flexible roof layers. The system, however, will fail in cold freezlng climates sioce any small hole (either accidental or otherwise) will allow the warm moist air to penetrate into the space between his roofs, freeze onto the mechanism, tear the walls and immobilize the blanket. Its very nature only allows it to be used on structures of short length, i.e., movable shelters.
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11~87~
Accordingly, an ob~ect of a broad aspect of this invention is to provide a system which has great economic significance for the greenhouse industry, is practical, economical and immediately usable.
An object of another aspect of this invention is to provide such a system which is simple and hence which has a very higX potential in the market place for all countries with cold climates.
An object of yet another aspect of this invention is to provide such a system which includes an automatic retraction device.
An object of still another aspect of this invention is to provide such a system whereby snow on the greenhouse is caused to melt or fall off naturally by retracting the blanket and by inflation and/or mechanical pulsations.
By one broad aspect of this invention, a structure is provided comprising an enclosure having an outer light-transparent wall and an inner light-transparent wall spaced apart from that outer wall, means for charging the space between the outer wall and the inner wall with air having a dew point so selected that it will not allow condensation to take placé under pressure, and an insulating layer disposed in the pressurized air space between the outer wall and the inner wall and comprising: (a) an insulating blanket disposed in the pressurized air space between the Outer wall and the inner wall and movable between an extended covering position and a retracted stored position within an enclosed storage area;
(b) means connected to a leading edge of the insulating blanket and positively operable to move the leading edge from its retracted stored position to its extended covering position; and (c) means operatively associated with the trailing portion of the insulating blanket and adapted to draw the insulating blanket from its extended covering position to its ret~e~ed stored position. -- - ¦
By one variant of this invention, the presssurized air space .
: ~ ;: ' , 11g~8741 may be disposed only in a horizontal or approximately horizontal position, in which case the insulating blanket is drawn across the horizontal area by carrier cables from an accordion-folded retracted stored position to an extended covering position, and vice versa, and with the leading edge at any selected position between extended and retracted:
By one variation thereof, the horizontal-type situation would be, for example, on a gutter-connected, pillow-type open greenhouse.
By another variant, the greenhouse of the gutter-connected pillow- type, open-type includes a roof of a plurality of inflated double-walled polyethylene pillows.
By another variant thereof, the insulating blanket is supportedat spaced-apart locations throughout its length by carrier cables, the carrier cables being movable in both directions under constant tension to extend or to retract the insulation blanket.
Another aspect of this invention is provided where the insula-ting blanket is drawn across a roof structure when it is disposed in a metal arch gutter-connected greenhouse. By a variant thereof, the insula-ting blanket would move in a generally one-half sinusoidal path.
By yet another variant, the greenhouse of the metal arch gutter-connected type includes an inner transparent layer of polyethyleneresting on the metal arched frames and separated from the outer polyethy-lene arch by the outside air under pressure.
By a variation thereof, the insulating blanket is supported by three longitudinally extending cables, which are under tension to enable movement of the blanket, but which, when relaxed, allow the insulating blanket to rest on the inner polyethylene layer to provide the covering insulatiD~ .
By a further variant-thereof,-~the=blanket-~s provided with -carrier cables, the carrier cables being movable transverse of and within , .
~1~874~
the arches in both directions under constant tension to extend or to retract the insulation blanket.
According to another aspect of this invention, if the greenhouse is a steep roof type or quonset hut type, the trailing edge is provided with a ballast weight or tension device, e.g., an electric tension cord to draw the blanket into a lower storage box. The storage box may or may not be insulated.
According to a further aspect of this invention, if the green-house is of the flat roof type, the insulating blanket is controlled by a two-rope constant-tension system. The insulation may be one extensive width or be of a plurality of butted batts of insulating blankets.
By another variant of this invention, the greenhouse if of the very flat roof hoop-type, and includes a plurality of such butted batts of insulation blankets, with extension and retraction being accomplished by a rope secured at one end to the leading edge of the insulation blanket and at its other end wrapped in one direction on a rotatable shaft, and a second rope wrapped in an opposite direction to the rotatable shaft and trained around a lower pulley and secured to a lower pull bar on the insulation blanket.
By yet another variant, in a very flat roof type greenhouse, a pair of rollers are provided engaging opposite faces of the insulation blanket to hold the insulation blanket to the vertical wall.
By yet another variant, the greenhouse is of the quonset hut type and the extension and retraction of the insulation blanket is accom-plished by a continuous rope, entraining a plurality of pulleys within the greenhouse, wound around a rotatable winding shaft and each end con-nected to the leading edge of the insulation blanket.
By another variant, the means (b) comprises a motor manually actuatable to move the insulating blanket to a selected position between ~'' _ g _ ~L~48741 its extended covering position and its retracted stored position, and to hold the blanket at that selected position.
: By another variant, the means tb) comprises a motor automatically actuatable in response to a preselected cycle automatically to move the insulating blanket in response to predetermined positions of the sun with respect to the greenhouse.
By a further variant thereofl one longitudinal half of the greenhouse has its insulating blanket in its extended covering position while the other longitudinal half of the greenhouse has its insulating blanket in its retracted stored position.
By another variant, one longitudinal half of the greenhouse has its insulating blanket movable between its extended covering position to its retracted stored position, while the other longitudinal half of the greenhouse has its insulating blanket movable between its retracted stored position and its extended covering position.
By a further variant, the greenhouse is of the hoop-type and includes an arched framework, an outer light-transparent covering there-over, a spaced-apart, inner, light-transparent membrane thereover, and fan means for inflating the space between the outer covering and the inner me~brane with outside air.
By yet another variant, the fan means introduces air into one of the storage boxes or above the boxes, or at any other convenient location.
By still another variant, the fan means introduces air into a header disposed at the apex crest of the arched structure, between the outer covering and the inner membrane.
By yet another variant of such greenhouse, the outer covering and the inner membrane each comprise a polyethylene sheet.
By_aDother aspect.of this invention, the greenhouse is of the rigid transparent, e.g., glass-type, and includes a rigid roof and wall system of rigid transparent, e.g., glass plates and an outer skin of flexible transparent plastic sheet disposed in spaced-apart relation from the rigid transparent, e.g., glass plates between the base of the struc-ture and the apex of the roof thereof, and includes fan means for intro-ducing the outside air under pressure between the rigid transparent, e.g., glass plates and the transparent skin to provide a double walled unit.
By another variant, the rigid transparent plates are, e.g., flat or corrugated sheet material made of glass fibers.
By another variant thereof?the fan means pressurizes the space of the storage boxes or above the boxes or at any other convenient loca-tion under conditions of zero or approaching zero flow, in order to mini-mize heat transfer and minimize fan power.
By another variant, the insulating blanket includes a pair of sealing skins with a filling of insulating material therebetween.
By a further variant thereof, one skin is formed of a pliable waterproof material, e.g., polyethylene or polyvinyl plastic.
By another variant, one skin is formed of an aluminized material.
By a further variant, the filling of insulating material is formed of a structurally integral glass fiber blanket.
By yet another variant, the insulating blanket includes a further portion comprising a mesh material to provide shading to restrict the amount of light entering the greenhouse.
Accordingly, this invention in its broad aspect addresses itself to several critical problems, namely, reduction of light by north wall insulation, the formation of ice on the structure covering and morning chill of crop, and wind problems and the economics, and substantially over-comes such problems by a movable layer of flexible insulation placed between~-the two spaced-apart walls of the greenhouse which are charged ~_~___ with pressurized air, depending on light and temperature conditions, to :.
il~874~ i minimize heating requirements. The inside cover of the insulation is pre-fersbly covered with a light-reflecting material, e.g., reinforced aluminized material, to enhance light conditions when partially covered.
The provision of the pressurized zone of gas between the outer and inner walls has the following advantages: ¦
(1) It substantially eliminates any freezing problem in the space containing the insulation since outdoor air entering into the struc-ture is dry and substantially prevents moisture penetration into the space from the interior.
(2) Because of the pressurization, a space is provided which is free of structure, that easily accommodates thick or thin insulation (up to 3" or more in thickness) and provides a space for a suitable windup mechanism. It can accommodate any length of greenhouse. The standard 100' greenhouse could thus use two 50' systems or any number of smaller sized modular systems.
(3) The complicated storage device is eliminated. In one embodiment, the insulation folds under the action of gravity, which effec-tively eliminates the lower roller.
(4) The system can be installed on an existing greenhouse struc-ture with minor modifications.
(5) The system can preferably be automated so that the insula-tion covers the greenhouse as night comes and lowers at dawn.
(6) The inflated layer contains dry air since the inflation is accomplished with outdoor air and no significant frost formation can occur.
The insulation is protected from the wind since it rests on the inner wall in a smooth cahnnel free of obstructions so that a movable insulating blanket may be drawn up at night and let down in the day. The ~` ` ` insulati~nri~ preferab-l~t-~- flexible glass--fiber-insulation-with-a.rein~
` forced light reflection backing which allows pulling of the flexible ~ 1~87~1 blanket.
Maximum effective light for growing with minimum heating is : achieved by drawing the insulating blanket part way up during early morning or late afternoon.
In the accompanying drawings, Figure 1 is a perspective view of the greenhouse of one embodi-ment of an aspect of the present invention;
Figure 2 is a transverse cross section through the embodiment of Figure l;
Figure 3 is a transverse cross section through a greenhouse of a second embodiment of an aspect of this invention;
Figure 4 is a transverse cross section through a greenhouse of a third embodiment of an aspect of this invention;
Figure 5 is a front elevational view of a gutter-connected pillow-type open greenhouse of another embodiment of an aspect of this invention;
Figure 6 is a side elevational view of the embodiment of Figure 5;
Figure 7 is a detail of the embodiment of Figure 5 showing the disposition of the insulating blanket and the extension and retraction thereof;
Figure 8 is a front elevational view of a metal arch gutter-connected greenhouse of yet another embodiment of an aspect of this invention;
Figure 9 is a detail of an arch of the embodiment of Figure 8, showing the disposition of the insulation blanket;
Figure 10 is a perspective view of a greenhouse of still ~~~-~~~~r~an-ot~-r-e-~odiment~~of an~~ p~F-~f this-invention which is a variation of the embodiment of Figure l;
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Figure 11 is a perspective detail view showing the extension and retraction of the insulation blanket;
: Figure 12 is a transverse cross section through the embodiment of Figure 10;
Figure 13 is a transverse cross section through yet another embodiment of an aspect of this invention which is another variation of the embodiment of Figure l; and Figure 14 is a cross section through a typical insulating blanket used in the greenhouse of embodiments of aspects of this invention.
As seen in Figures 1 and 2, the greenhouse structure 10 includes an arched framework 11 supporting an outer transparent covering 12 and an inner transparent membrane 13. A fan 14 fills the space between outer covering 12 and inner transparent membrane 13 with pressurized dry outdoor air through a header 14a, which air may be heated air in order to heat the greenhouse in winter.
The insulation system 20 of an embodiment of this invention includes a storage box 21 (which may or may not be insulated) at the base 22 of the greenhouse 10 and a longitudinal roller 23 at the crest of the greenhouse 10. A reversing motor 24 is provided having a sprocket 25 the thereon driving a sprocket 26 on the roller 23 by means of a chain 27 or alternatively by a direct drive to the roller 23. Secured and entrained on roller 23 is a plurality of ropes 28 whose free ends 29 are secured to the upper edge 30 of an insulation blanket 31. The lower edge 32 of the insulation blanket 31 is secured to the bottom 33 of the storage box 21 (which may or may not be insulated) and is also provided with a longitu-dinally extending lower ballsst weight 34. Ballast weight 34 should be located three feet above the ground level 33 in order to pull the blanket - 31 in its initial stages~
~ ' In operation, rotation of the motor 24 in one direction causes .
: : ,. ,, :, , "
. ~ ~
11'~879~1 , the ropes 28 to wind up on the roller 23, thereby drawing the insulation blanket 31 up to its extended covering position against the force exerted by the weight of the blanket 31 and the weight of the ballast 34. Rota-tion of the motor 24 in the reverse direction allows the blanket 31 to be drawn down by its own weight and the weight of the ballast 34 into the storage box 21 (which may or may not be insulated) in a natural accordion-type fold to its retracted stored position.
As seen in Figure 3, the greenhouse 310 includes an arched framework 311 supporting an outer transparent covering 312 and an inner membrane 313. ~ fan 314 fills the space between outer coverings 312 and inner membrane 313 with outside air through an inlet 314a at the bottom 322 of the storage box 321 (which may or may not be insulated), which air may be heated air in order to heat the greenhouse 310 in winter.
The insulation system 320 of an embodiment of this invention includes a storage box 321 (which may or may not be insulated) at the base 322 of the greenhouse 310 and a longitudinal roller 323 at the crest of the greenhouse 310. A reversing motor 324 is provided having a sprocket 325 thereon driving a sprocket 326 on the roller 323. In another alter-native, a pullcord (not shown) may be used for manual operation. The roller 323 may be located either between the covering layers 312 and 313, or outside the inner layer of the greenhouse 310. Secured and entrained on roller 323 is a plurality of ropes 328 whose free ends 329 are secured to the upper edge 330 of an insulation blanket 331. The lower edge 332 of the insulation blanket 331 is secured to the bottom 322 of the storage box 321 (which may or may not be insulated) and is also provided with a longitudinally extending lower ballast 334.
In operation, rotation of the motor 324 in one direction causes the ropes 328=~o wind-up on the roll~r~-323~-.thereby~drawing the insulation blanket 331 up to its extended covering position against the force exerted -.- : ' ,"` ~ ~
by the weight of the blanket 331 and the weight of the ballast 334.
Rotation of the motor 324 in the reverse direction allows the blanket 331 to be drawn down by its own weight and the weight of the ballast into the storage box 321 (which may or may not be insulated) in a natural accordion-type fold to its retracted stored position. As shown, however, the green-house 310 is so fitted with two rollers that one longitudinal half has its blanket in the lower retracted stored position to allow early morning sun to enter the greenhouse, while the other longitudinal half has its insula-ting blanket in its upper extended covering position. The blankets are switched in their dispositions as the day progresses.
The blanket falls within the storage box 321 (which may or may not be insulated) due to its own weight and the weight of the ballast 334.
It may be guided by means of tracks (not shown) at the ends of or in the greenhouse.
As seen in Figure 4, the greenhouse 410 includes a standard glass framed greenhouse 411 including an inner rigid series of panels 412 (which may be either of glass or of transparent plastic). It is modified by an outer transparent covering 413 of polyethylene sheet, joined to the stor-age box 421 (which may or may not be insulated) at its lower end, and to the apex 450 of the greenhouse 410 at its upper end. A fan 414 fills the space between inner coverings 412 and outer membrane or membranes 413 through an inlet 414a at the bottom 422 of the storage box 421 (which may or may not be insulated), ~hich air may be heated air in order to heat the greenhouse 410 in winter.
The insulation system 420 of an emhodiment of this invention includes a storage box 421 (which may or may not be insulated) at the base 422 of the greenhouse 410 and a longitudinal roller 423 at the crest of e~eenhouse ~llO. A reversing_motor 424 is_pro~ided_haying=a=spracket_ _ 425 thereon driving a sprocket 426 on the roller 423 by means of a chain ,~, '~- " ': , , , ~ :
11~8741 427 or alternatively by direct drive to the roller 423. Secured and entrained on roller 423 is a plurality of ropes 428 whose free ends 429 are secured to the upper edge 430 of an insulation blanket 431. The lower edge 432 of the insulation blanket 431 is secured to the bottom 422 of the storage box 421 (which may or may not be insulated) and is also provided with a longitudinally extending lower ballast 434.
In operation, rotation of the motor 424 in one directiGn causes the ropes 428 to wind up on the roller 423, thereby drawing the insulation blanket 431 up to its extended covering position against the force exerted 10 by the weight of the blanket 431 and the weight of the ballast 434. Rota-tion of the motor 424 in the reverse direction allows the blanket 431 to be drawn down by its own weight and the weight of the ballast 434 into the insulated storage box 421 (which may or may not be insulated) in a natural accordion-type fold to its retracted stored position. The insulation take-up can be either accordion fold (as described) or on a roller (not shown).
As shown, however, the greenhouse 410 is so fitted with two rollers that one longitudinal half has its blanket in the lower retracted stored posi-tion to allow early morning sun to enter the greenhouse, while the other longitudinal half, on a second roller,~has its insulating blanket in its upper extended covering position. The insulating blankets are switched in their dispositions as the day progresses.
The insulating blanket 431 falls within the storage box 421 (which may or may not be insulated) due to its own weight and the weight of the ballast 434. It may be guided by means of tracks at-the ends and rollers 451 at the sides of the greenhouse.
The greenhouse 510 of Figures 5, 6 and 7 includes a plurality of upright columns supporting gutters 511a which, in turn, support a plurality -of inflatedipi-L~ffw~po~yethy~ene~covers-comprising an outer skin~5-1-3-wi~h--~ --outside air, which air may be heated air in order to heat the greenhouse '.~
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510 in winter.
The insulation system of an embodiment of this invention includes .
: a horizontal storage box 521 above the header house 514a. An insulationblanket 531 extends across the inflated pillow covers. Three ropes or cables 540, 541, 542 which extend longitudinally of the greenhouse are anchored to a cross-brace at both ends of the greenhouse 510 (not shown) to support the insulation blanket 531 with grommets 543 for vertical move-ment between a tensed condition, (in which the inflated pillow is not covered by the insulation blanket 531 for insulation purposes) and a relaxed condition (in which the insulation blanket 531 is resting on the inner skin 513 for insulation purposes). One such cable tensioning device may be a hydraulic cylinder whose rod end is provided with a pulley entrained by the cable. Another cable 544 may be a moving device.
The insulation blanket 531 may be retracted to the accordion folded condition shown in ~igure 6 by drawing a clamp (not shown) at the leading end of the respective cable from the forward end of the greenhouse 510 to the storage end at the storage box 521.
The embodiment of greenhouse 810 shown in Figures 8 and 9 is virtually the same as that shown in Figures 5, 6 and 7 and so the same parts will be designated on the drawings by the same reference numeral in the "800" series rather than the "SOO" series but will not be described in detail. The only significant dlfference between the "500" embodiment and the "800" embodiment is that the metal arch gutter-connected greenhouse of Figures 8 and 9 includes a metal arch framework 811b interconnecting the gutters 811a resting atop the gutter support columns 811. The outer skin 812 is fixed to the gutters 811a spaced away from the metal arch framework 811b, while the inner skin 813 rests on the metal arch 811b.
~ ~ ~~~`~~~~~~~ ~~~ ---~~~~~The~ranstruction-~and~peration-~--the-~insulation~baanket~831 -~ the same as in the embodiment of Figures 5, 6 and 7.
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: ' , .
~8741 The embodiment shown in Figures 10, 11 and 12 is virtually the same as the embodiment shown in Figure 1 and hence the same parts will be designated on the drawings by the same reference numeral in the "1000"
~ .
series rather than in the "10" series, but will not be otherwise described.
Because the greenhouse 1010 is a very flat roof quonset hut type green-house, a different extension - retraction system is used.
The insulation blanket 1031 is provided as a plurality of narrow butted batts 1031a, 1031b, 1031c, etc. and are extended and retracted by a two-rope system. One rope 1041 is connected to the leading edge 1030 of insulation blanket batt 1031a and extends to a pulley 1026a, mounted on the ridgeboard 1050 and then is wound on a winding shaft 1023 in an opposite direction and extends within the inner polyethylene membrane 1013 guided by pulley 1043 to the storage box 1021 where it is guided by pulley 1044 and 1045 within the pressurized air layer to be secured to the leading edge 1030 of the insulating blanket batt 1031a.
As also seen in Figure 12 at the junction of the roof and the wall, the insulation blanket batts 1031a, etc. pass on the outside of roller 1046 and on the inside of roller 1047 in order to hold the insula-tion 1031a, etc. tight to the wall. An alternative retraction system is a tension device (e.g., a stretchable rope) 1047 pulled tight on ralsing the insulation 1031.
Thus, rotation of the winding shaft 1023 in one direction results in extension of the insulation blanket batt 1031a to its covering position, while rotation of the winding shaft 1023 in an opposite direction results in retracting the insulation blanket batt 1031a within storage box 1021 in accordion folded form. The ropes 1041 and 1042 are maintained under constant tension to facilitate accurate operation. The other insulation blanket~batts.l031b,~1031c, etc.~are~operated in a like fashion.~ ~
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The embodiment shown in Figure 13 is virtually identical to the -, 11~8~41 embodiment shown in Figure 1 and hence the same parts will be designated on the drawings by the same reference numeral in the "1300" series rather than the "10" series, but will not be otherwise described. Because the greenhouse 1310 is a very flat roof quonset hut type greenhouse, a dif-ferent extension - retraction system is used.
The insulation blanket 1331 is extended and retracted by a con-tinuous rope system. ~he-rope 1340 is secured to the inside edge 1330a of the leading edge 1330 of the insulation blanket 1331. It then passes a pulley 1341 on the ridge 1339 where it is wound on winding drive shaft 1323 driven by a motor as previously described. Now within the interior of the greenhouse 1310, the rope is guided by pulleys 1342-1345 to the botton in-terior of the greenhouse 1310. The rope 1340 fits between the insulation blanket batts 1331 and is secured to the outside edge 1330b of the leading edge 1330 of the insulation blanket. The leading edge 1330 is preferably a pull bar.
The rop~ 1340 is preferably a woven band (e.g., a 2" x 1/16") which minimizes wear on the polyethylene and rolls on the shaft without sideways movement.
Thus rotation of the winding shaft 1323 in one direction results in extension of the insulation blanket batt 1331, while rotation of the winding shaft 1323 in the opposite direction results in retracting the in-sulation blanket batt 1331 within the storage box 1321 in accordion folded form.
As seen in Figure 14, a typical blanket 1410 includes one skin 1411 of a pliable waterproof material, e.g., polyethylene or polyvinyl plastic film, and another skin 1412 of aluminized material. Between the skins is the insulation material, preferably a self-sustaining flexible pad of glass fibers 1413. The ballast weight 1434 at the bottom but which .
-.
:
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1~48741 is preferably three feet off the ground is also shown. A top ballast 1430, connected to skins 1411 and 1412 and to pad 1413 is also shown.
- 20 a -' - ' .
11~8~4~ ~
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The economics of the system of this invention pro~ected from the l:
cost of the present systems is about $28,000 per acre, while saving `~ $24,000 per year in natural gas fuel bills, (at Western Canada prices).
At the present price of oil, the cost of the system would be repaid in less than one year.
The disposition of the insulation outside the greenhouse struc-ture proper in a pressurized zone rather than in the unpressurized zone described by Cary provides a significant advance over the prior art. The improvement can be used with greenhouses with inflated polyethylene outer layers or existing glasshouses with inflated layers added to reduce heating to 1/3 or less the present uninsulated or uncovered structure heating costs. In addition, the advantages of the pressurized system are so great (especially low cost) that the present invention has the poten-tial of developing into a standard system for commercial, backyard green-houses, swimming pools and any structure requiring sunshine or the benefits of solar energy. It can also be used in implement storage areas to pro-vide a warm dry environment by the double layers of polyethylene. On cloudy days or at night the insulation blanket could be used.
:
The insulation is protected from the wind since it rests on the inner wall in a smooth cahnnel free of obstructions so that a movable insulating blanket may be drawn up at night and let down in the day. The ~` ` ` insulati~nri~ preferab-l~t-~- flexible glass--fiber-insulation-with-a.rein~
` forced light reflection backing which allows pulling of the flexible ~ 1~87~1 blanket.
Maximum effective light for growing with minimum heating is : achieved by drawing the insulating blanket part way up during early morning or late afternoon.
In the accompanying drawings, Figure 1 is a perspective view of the greenhouse of one embodi-ment of an aspect of the present invention;
Figure 2 is a transverse cross section through the embodiment of Figure l;
Figure 3 is a transverse cross section through a greenhouse of a second embodiment of an aspect of this invention;
Figure 4 is a transverse cross section through a greenhouse of a third embodiment of an aspect of this invention;
Figure 5 is a front elevational view of a gutter-connected pillow-type open greenhouse of another embodiment of an aspect of this invention;
Figure 6 is a side elevational view of the embodiment of Figure 5;
Figure 7 is a detail of the embodiment of Figure 5 showing the disposition of the insulating blanket and the extension and retraction thereof;
Figure 8 is a front elevational view of a metal arch gutter-connected greenhouse of yet another embodiment of an aspect of this invention;
Figure 9 is a detail of an arch of the embodiment of Figure 8, showing the disposition of the insulation blanket;
Figure 10 is a perspective view of a greenhouse of still ~~~-~~~~r~an-ot~-r-e-~odiment~~of an~~ p~F-~f this-invention which is a variation of the embodiment of Figure l;
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Figure 11 is a perspective detail view showing the extension and retraction of the insulation blanket;
: Figure 12 is a transverse cross section through the embodiment of Figure 10;
Figure 13 is a transverse cross section through yet another embodiment of an aspect of this invention which is another variation of the embodiment of Figure l; and Figure 14 is a cross section through a typical insulating blanket used in the greenhouse of embodiments of aspects of this invention.
As seen in Figures 1 and 2, the greenhouse structure 10 includes an arched framework 11 supporting an outer transparent covering 12 and an inner transparent membrane 13. A fan 14 fills the space between outer covering 12 and inner transparent membrane 13 with pressurized dry outdoor air through a header 14a, which air may be heated air in order to heat the greenhouse in winter.
The insulation system 20 of an embodiment of this invention includes a storage box 21 (which may or may not be insulated) at the base 22 of the greenhouse 10 and a longitudinal roller 23 at the crest of the greenhouse 10. A reversing motor 24 is provided having a sprocket 25 the thereon driving a sprocket 26 on the roller 23 by means of a chain 27 or alternatively by a direct drive to the roller 23. Secured and entrained on roller 23 is a plurality of ropes 28 whose free ends 29 are secured to the upper edge 30 of an insulation blanket 31. The lower edge 32 of the insulation blanket 31 is secured to the bottom 33 of the storage box 21 (which may or may not be insulated) and is also provided with a longitu-dinally extending lower ballsst weight 34. Ballast weight 34 should be located three feet above the ground level 33 in order to pull the blanket - 31 in its initial stages~
~ ' In operation, rotation of the motor 24 in one direction causes .
: : ,. ,, :, , "
. ~ ~
11'~879~1 , the ropes 28 to wind up on the roller 23, thereby drawing the insulation blanket 31 up to its extended covering position against the force exerted by the weight of the blanket 31 and the weight of the ballast 34. Rota-tion of the motor 24 in the reverse direction allows the blanket 31 to be drawn down by its own weight and the weight of the ballast 34 into the storage box 21 (which may or may not be insulated) in a natural accordion-type fold to its retracted stored position.
As seen in Figure 3, the greenhouse 310 includes an arched framework 311 supporting an outer transparent covering 312 and an inner membrane 313. ~ fan 314 fills the space between outer coverings 312 and inner membrane 313 with outside air through an inlet 314a at the bottom 322 of the storage box 321 (which may or may not be insulated), which air may be heated air in order to heat the greenhouse 310 in winter.
The insulation system 320 of an embodiment of this invention includes a storage box 321 (which may or may not be insulated) at the base 322 of the greenhouse 310 and a longitudinal roller 323 at the crest of the greenhouse 310. A reversing motor 324 is provided having a sprocket 325 thereon driving a sprocket 326 on the roller 323. In another alter-native, a pullcord (not shown) may be used for manual operation. The roller 323 may be located either between the covering layers 312 and 313, or outside the inner layer of the greenhouse 310. Secured and entrained on roller 323 is a plurality of ropes 328 whose free ends 329 are secured to the upper edge 330 of an insulation blanket 331. The lower edge 332 of the insulation blanket 331 is secured to the bottom 322 of the storage box 321 (which may or may not be insulated) and is also provided with a longitudinally extending lower ballast 334.
In operation, rotation of the motor 324 in one direction causes the ropes 328=~o wind-up on the roll~r~-323~-.thereby~drawing the insulation blanket 331 up to its extended covering position against the force exerted -.- : ' ,"` ~ ~
by the weight of the blanket 331 and the weight of the ballast 334.
Rotation of the motor 324 in the reverse direction allows the blanket 331 to be drawn down by its own weight and the weight of the ballast into the storage box 321 (which may or may not be insulated) in a natural accordion-type fold to its retracted stored position. As shown, however, the green-house 310 is so fitted with two rollers that one longitudinal half has its blanket in the lower retracted stored position to allow early morning sun to enter the greenhouse, while the other longitudinal half has its insula-ting blanket in its upper extended covering position. The blankets are switched in their dispositions as the day progresses.
The blanket falls within the storage box 321 (which may or may not be insulated) due to its own weight and the weight of the ballast 334.
It may be guided by means of tracks (not shown) at the ends of or in the greenhouse.
As seen in Figure 4, the greenhouse 410 includes a standard glass framed greenhouse 411 including an inner rigid series of panels 412 (which may be either of glass or of transparent plastic). It is modified by an outer transparent covering 413 of polyethylene sheet, joined to the stor-age box 421 (which may or may not be insulated) at its lower end, and to the apex 450 of the greenhouse 410 at its upper end. A fan 414 fills the space between inner coverings 412 and outer membrane or membranes 413 through an inlet 414a at the bottom 422 of the storage box 421 (which may or may not be insulated), ~hich air may be heated air in order to heat the greenhouse 410 in winter.
The insulation system 420 of an emhodiment of this invention includes a storage box 421 (which may or may not be insulated) at the base 422 of the greenhouse 410 and a longitudinal roller 423 at the crest of e~eenhouse ~llO. A reversing_motor 424 is_pro~ided_haying=a=spracket_ _ 425 thereon driving a sprocket 426 on the roller 423 by means of a chain ,~, '~- " ': , , , ~ :
11~8741 427 or alternatively by direct drive to the roller 423. Secured and entrained on roller 423 is a plurality of ropes 428 whose free ends 429 are secured to the upper edge 430 of an insulation blanket 431. The lower edge 432 of the insulation blanket 431 is secured to the bottom 422 of the storage box 421 (which may or may not be insulated) and is also provided with a longitudinally extending lower ballast 434.
In operation, rotation of the motor 424 in one directiGn causes the ropes 428 to wind up on the roller 423, thereby drawing the insulation blanket 431 up to its extended covering position against the force exerted 10 by the weight of the blanket 431 and the weight of the ballast 434. Rota-tion of the motor 424 in the reverse direction allows the blanket 431 to be drawn down by its own weight and the weight of the ballast 434 into the insulated storage box 421 (which may or may not be insulated) in a natural accordion-type fold to its retracted stored position. The insulation take-up can be either accordion fold (as described) or on a roller (not shown).
As shown, however, the greenhouse 410 is so fitted with two rollers that one longitudinal half has its blanket in the lower retracted stored posi-tion to allow early morning sun to enter the greenhouse, while the other longitudinal half, on a second roller,~has its insulating blanket in its upper extended covering position. The insulating blankets are switched in their dispositions as the day progresses.
The insulating blanket 431 falls within the storage box 421 (which may or may not be insulated) due to its own weight and the weight of the ballast 434. It may be guided by means of tracks at-the ends and rollers 451 at the sides of the greenhouse.
The greenhouse 510 of Figures 5, 6 and 7 includes a plurality of upright columns supporting gutters 511a which, in turn, support a plurality -of inflatedipi-L~ffw~po~yethy~ene~covers-comprising an outer skin~5-1-3-wi~h--~ --outside air, which air may be heated air in order to heat the greenhouse '.~
!
- ~ :
-~ ~4874I ~
510 in winter.
The insulation system of an embodiment of this invention includes .
: a horizontal storage box 521 above the header house 514a. An insulationblanket 531 extends across the inflated pillow covers. Three ropes or cables 540, 541, 542 which extend longitudinally of the greenhouse are anchored to a cross-brace at both ends of the greenhouse 510 (not shown) to support the insulation blanket 531 with grommets 543 for vertical move-ment between a tensed condition, (in which the inflated pillow is not covered by the insulation blanket 531 for insulation purposes) and a relaxed condition (in which the insulation blanket 531 is resting on the inner skin 513 for insulation purposes). One such cable tensioning device may be a hydraulic cylinder whose rod end is provided with a pulley entrained by the cable. Another cable 544 may be a moving device.
The insulation blanket 531 may be retracted to the accordion folded condition shown in ~igure 6 by drawing a clamp (not shown) at the leading end of the respective cable from the forward end of the greenhouse 510 to the storage end at the storage box 521.
The embodiment of greenhouse 810 shown in Figures 8 and 9 is virtually the same as that shown in Figures 5, 6 and 7 and so the same parts will be designated on the drawings by the same reference numeral in the "800" series rather than the "SOO" series but will not be described in detail. The only significant dlfference between the "500" embodiment and the "800" embodiment is that the metal arch gutter-connected greenhouse of Figures 8 and 9 includes a metal arch framework 811b interconnecting the gutters 811a resting atop the gutter support columns 811. The outer skin 812 is fixed to the gutters 811a spaced away from the metal arch framework 811b, while the inner skin 813 rests on the metal arch 811b.
~ ~ ~~~`~~~~~~~ ~~~ ---~~~~~The~ranstruction-~and~peration-~--the-~insulation~baanket~831 -~ the same as in the embodiment of Figures 5, 6 and 7.
. .
: ' , .
~8741 The embodiment shown in Figures 10, 11 and 12 is virtually the same as the embodiment shown in Figure 1 and hence the same parts will be designated on the drawings by the same reference numeral in the "1000"
~ .
series rather than in the "10" series, but will not be otherwise described.
Because the greenhouse 1010 is a very flat roof quonset hut type green-house, a different extension - retraction system is used.
The insulation blanket 1031 is provided as a plurality of narrow butted batts 1031a, 1031b, 1031c, etc. and are extended and retracted by a two-rope system. One rope 1041 is connected to the leading edge 1030 of insulation blanket batt 1031a and extends to a pulley 1026a, mounted on the ridgeboard 1050 and then is wound on a winding shaft 1023 in an opposite direction and extends within the inner polyethylene membrane 1013 guided by pulley 1043 to the storage box 1021 where it is guided by pulley 1044 and 1045 within the pressurized air layer to be secured to the leading edge 1030 of the insulating blanket batt 1031a.
As also seen in Figure 12 at the junction of the roof and the wall, the insulation blanket batts 1031a, etc. pass on the outside of roller 1046 and on the inside of roller 1047 in order to hold the insula-tion 1031a, etc. tight to the wall. An alternative retraction system is a tension device (e.g., a stretchable rope) 1047 pulled tight on ralsing the insulation 1031.
Thus, rotation of the winding shaft 1023 in one direction results in extension of the insulation blanket batt 1031a to its covering position, while rotation of the winding shaft 1023 in an opposite direction results in retracting the insulation blanket batt 1031a within storage box 1021 in accordion folded form. The ropes 1041 and 1042 are maintained under constant tension to facilitate accurate operation. The other insulation blanket~batts.l031b,~1031c, etc.~are~operated in a like fashion.~ ~
!
The embodiment shown in Figure 13 is virtually identical to the -, 11~8~41 embodiment shown in Figure 1 and hence the same parts will be designated on the drawings by the same reference numeral in the "1300" series rather than the "10" series, but will not be otherwise described. Because the greenhouse 1310 is a very flat roof quonset hut type greenhouse, a dif-ferent extension - retraction system is used.
The insulation blanket 1331 is extended and retracted by a con-tinuous rope system. ~he-rope 1340 is secured to the inside edge 1330a of the leading edge 1330 of the insulation blanket 1331. It then passes a pulley 1341 on the ridge 1339 where it is wound on winding drive shaft 1323 driven by a motor as previously described. Now within the interior of the greenhouse 1310, the rope is guided by pulleys 1342-1345 to the botton in-terior of the greenhouse 1310. The rope 1340 fits between the insulation blanket batts 1331 and is secured to the outside edge 1330b of the leading edge 1330 of the insulation blanket. The leading edge 1330 is preferably a pull bar.
The rop~ 1340 is preferably a woven band (e.g., a 2" x 1/16") which minimizes wear on the polyethylene and rolls on the shaft without sideways movement.
Thus rotation of the winding shaft 1323 in one direction results in extension of the insulation blanket batt 1331, while rotation of the winding shaft 1323 in the opposite direction results in retracting the in-sulation blanket batt 1331 within the storage box 1321 in accordion folded form.
As seen in Figure 14, a typical blanket 1410 includes one skin 1411 of a pliable waterproof material, e.g., polyethylene or polyvinyl plastic film, and another skin 1412 of aluminized material. Between the skins is the insulation material, preferably a self-sustaining flexible pad of glass fibers 1413. The ballast weight 1434 at the bottom but which .
-.
:
~ . .
1~48741 is preferably three feet off the ground is also shown. A top ballast 1430, connected to skins 1411 and 1412 and to pad 1413 is also shown.
- 20 a -' - ' .
11~8~4~ ~
~.
The economics of the system of this invention pro~ected from the l:
cost of the present systems is about $28,000 per acre, while saving `~ $24,000 per year in natural gas fuel bills, (at Western Canada prices).
At the present price of oil, the cost of the system would be repaid in less than one year.
The disposition of the insulation outside the greenhouse struc-ture proper in a pressurized zone rather than in the unpressurized zone described by Cary provides a significant advance over the prior art. The improvement can be used with greenhouses with inflated polyethylene outer layers or existing glasshouses with inflated layers added to reduce heating to 1/3 or less the present uninsulated or uncovered structure heating costs. In addition, the advantages of the pressurized system are so great (especially low cost) that the present invention has the poten-tial of developing into a standard system for commercial, backyard green-houses, swimming pools and any structure requiring sunshine or the benefits of solar energy. It can also be used in implement storage areas to pro-vide a warm dry environment by the double layers of polyethylene. On cloudy days or at night the insulation blanket could be used.
:
Claims (36)
1. A structure comprising: an enclosure having an outer light-transparent wall and an inner light-transparent wall spaced apart from said outer wall; means for charging the space between said outer wall and said inner wall with air, having a dew point so selected that it will not allow condensation to occur, under pressure; and an insulating layer dis-posed in said pressurized air space between said outer wall and said inner wall, said insulating layer comprising:
(a) an insulating blanket disposed in said pressurized air space between said outer wall and said inner wall and movable between an extended covering position and a retracted stored position within an enclosed storage area;
(b) means connected to a leading edge of said insulating blanket and positively operable to move the leading edge from its retracted stored position to its extended covering position;
and (c) means operatively associated with the trailing portion of said insulating blanket and adapted to draw the insulating blanket from its extended covering position to its retracted stored position.
(a) an insulating blanket disposed in said pressurized air space between said outer wall and said inner wall and movable between an extended covering position and a retracted stored position within an enclosed storage area;
(b) means connected to a leading edge of said insulating blanket and positively operable to move the leading edge from its retracted stored position to its extended covering position;
and (c) means operatively associated with the trailing portion of said insulating blanket and adapted to draw the insulating blanket from its extended covering position to its retracted stored position.
2. The structure of claim 1 wherein said structure is a gutter-connected, pillow-type open greenhouse; wherein said pressurized air space is disposed only in a horizontal or approximately horizontal position; and wherein said insulating blanket is adapted to be drawn across the horizon-tal area by carrier cables from an accordion-folded retracted, stored position to an extended covering position, and vice versa, and with the leading edge thereof at any selected position between said extended posi-tion and said retracted position.
3. The structure of claim 1 wherein said structure is a metal arch, gutter-connected greenhouse; wherein said pressurized air space is provided in a plurality of one-half sine waves; and wherein said insulating blanket is adapted to be drawn across the horizontal area by carrier cables from an accordion-folded retracted, stored position to an extended covering position, and vice versa, and with the leading edge thereof at any selected position between said extended position and said retracted position.
4. The structure of claim 1, wherein said structure is a green-house of the steep roof-type or quonset hut-type; and wherein said trailing edge of said insulating blanket is provided with a ballast weight to draw said insulating blanket into a lower storage box.
5. The structure of claim 4 wherein said storage box is insulated.
6. The structure of claim 1 wherein said structure is a green-house of the flat roof or shallow quonset hut-type, and wherein movement of said insulating blanket is controlled by a constant-tension rope system.
7. The structure of claim 1 wherein said constant-tension rope system comprises two oppositely pulling ropes.
8. The structure of claim 1 wherein said constant-tension rope system comprises one continuous rope.
9. The structure of claim 1 wherein said insulating blanket extends substantially the entire length of said structure.
10. The structure of claim 1 wherein said insulating blanket comprises a plurality of butted insulating blanket batts.
11. The structure of claim 1 wherein said means (b) comprises a motor manually actuatable to move said insulating blanket to a selected position between its extended covering position and its retracted stored position, and to hold said insulating blanket at that selected position.
12. The structure of claim 1 wherein said means (b) comprises a motor automatically actuatable in response to a preselected cycle auto-matically to move said insulating blanket in response to predetermined positions of the sun with respect to said structure.
13. The structure of claim 1 wherein one longitudinal half of said structure has its insulating blanket in its extended covering position while the other longitudinal half of said structure has its insulating blanket in its retracted stored position.
14. The structure of claim 1 wherein one longitudinal half of said structure has its insulating blanket movable between its extended covering position and its retracted stored position, while the other longitudinal half of said greenhouse has its insulating blanket movable between its retracted stored position and its extended covering position.
15. The greenhouse of claim 4 wherein said greenhouse is of the hoop-type and includes: an arched framework; an outer light-transparent covering thereover; a spaced-apart, inner, light-transparent membrane thereover; and fan means for inflating the space between said outer covering and said inner membrane with outside air under pressure.
16. The greenhouse of claim 15 wherein said fan means introduces air into the storage box or above the box, or at any other convenient location.
17. The greenhouse of claim 15 wherein said fan means introduces air into a header disposed at the apex crest of said arched structure, between said outer covering and said inner membrane.
18. The greenhouse of claim 15 wherein said outer covering and said inner membrane each comprise a polyethylene sheet.
19. The greenhouse of claim 4 wherein said greenhouse is of the glass (or equivalent) type and includes a rigid roof and wall system of transparent glass (or equivalent) plates, and an outer skin of flexible transparent plastic sheet disposed in spaced-apart relation from the transparent glass (or equivalent) plates between the base of the structure and the apex of the roof thereof; and wherein said greenhouse includes fan means for introducing outside air under pressure between the rigid (or equivalent) plates and the transparent skin, thereby to provide a double-walled unit.
20. The greenhouse of claim 19 wherein said fan means introduces air into one of the storage boxes or above the box or at any other conveni-ent point.
21. The greenhouse of claim 19 wherein said transparent plates comprise glass plates.
22. The greenhouse of claim 19 wherein said transparent plates comprise flat or corrugated sheet material made of glass fibers, acrylic or like plastics material.
23. The greenhouse of claim 2 wherein said greenhouse includes a roof of a plurality of inflated double-walled polyethylene pillows.
24. The greenhouse of claim 23 wherein said insulating blanket is supported at spaced-apart locations throughout its length by carrier cables, said carrier cables being movable in both directions under constant tension to extend or to retract the insulation blanket.
25. The greenhouse of claim 3 wherein said roof includes an inner transparent layer of polyethylene resting on metal arched frames and separated from an outer polyethylene arch by outside air under pressure.
26. The greenhouse of claim 25 wherein said insulating blanket is supported by three longitudinally extending cables, which are under tension to enable movement of said insulating blanket, but which, when relazed, allow the insulating blanket to rest on the inner polyethylene layer to provide the covering insulation.
27. The greenhouse of claim 26 wherein said insulating blanket is provided with carrier cables, said carrier cables being movable trans-versely of, and within, said arches in both directions under constant tension to extend or to retract said insulation blanket.
28. The greenhouse of claim 6 wherein said insulating blanket includes a plurality of insulation blanket batts with extension and retraction being accomplished by a rope secured at one end to the leading edge of said insulation blanket and at its other end wrapped in one direc-tion on a rotatable shaft, and a second rope wrapped in an opposite direction to the rotatable shaft and trained around a lower pulley and secured to a pull bar on said insulation blanket.
29. The greenhouse of claim 28 including a pair of rollers engaging opposite faces of said insulation blanket to hold said insulation blanket to the vertical wall.
30. The greenhouse of claim 6 wherein extension and retraction of said insulation blanket is accomplished by a continuous rope, entraining a plurality of pulleys within said greenhouse, wound around a rotatable winding shaft and each end connected to the leading edge of said insula-tion blanket.
31. The structure of claim 1 wherein said insulating blanket includes a pair of sealing skins with a filling of insulating material therebetween.
32. The structure of claim 31 wherein one skin is formed of a pliable waterproof material, e.g., polyethylene or polyvinyl plastic.
33. The structure of claim 31 wherein one skin is formed of an aluminized material.
34. The structure of claim 31 wherein said filling of insulating material is formed of a structurally integral glass fiber blanket.
35. The structure of claim 31 wherein said insulating blanket is composed of a single, or woven pliable flexible film which may be black, aluminized or woven polyethylene.
36. The structure of claim 31 wherein said insulating blanket includes a further portion comprising a mesh material to provide shading to restrict the amount of light entering the greenhouse.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000357144A CA1148741A (en) | 1980-07-28 | 1980-07-28 | Method and apparatus for retaining heat in greenhouse and similar structures |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000357144A CA1148741A (en) | 1980-07-28 | 1980-07-28 | Method and apparatus for retaining heat in greenhouse and similar structures |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1148741A true CA1148741A (en) | 1983-06-28 |
Family
ID=4117519
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000357144A Expired CA1148741A (en) | 1980-07-28 | 1980-07-28 | Method and apparatus for retaining heat in greenhouse and similar structures |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1148741A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103299859A (en) * | 2012-03-12 | 2013-09-18 | 王忠方 | Low-carbon and environment-friendly multifunctional green house capable of saving energy and reducing emission |
| CN104186248A (en) * | 2014-08-31 | 2014-12-10 | 张家港市盛港防火板业科技有限公司 | Heat preservation board used for agricultural greenhouse |
| EP3342277A4 (en) * | 2015-08-27 | 2018-09-26 | The University Of Tokyo | Greenhouse for plant cultivation |
| US10426103B2 (en) | 2015-02-24 | 2019-10-01 | Gaïa Écosystèmes Inc. | Multilevel closed ecosystem greenhouse |
| CN112544303A (en) * | 2020-12-29 | 2021-03-26 | 呼伦贝尔学院 | Be used for high latitude severe cold district to abandon fire clean energy type double-framework main part greenhouse temperature canopy structure of surviving winter |
| CN118488779A (en) * | 2021-11-07 | 2024-08-13 | 亚历山大·保罗 | System and method for on-demand insulation between layers of a double layer window |
-
1980
- 1980-07-28 CA CA000357144A patent/CA1148741A/en not_active Expired
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103299859A (en) * | 2012-03-12 | 2013-09-18 | 王忠方 | Low-carbon and environment-friendly multifunctional green house capable of saving energy and reducing emission |
| CN104186248A (en) * | 2014-08-31 | 2014-12-10 | 张家港市盛港防火板业科技有限公司 | Heat preservation board used for agricultural greenhouse |
| US10426103B2 (en) | 2015-02-24 | 2019-10-01 | Gaïa Écosystèmes Inc. | Multilevel closed ecosystem greenhouse |
| EP3342277A4 (en) * | 2015-08-27 | 2018-09-26 | The University Of Tokyo | Greenhouse for plant cultivation |
| US10575473B2 (en) | 2015-08-27 | 2020-03-03 | The University Of Tokyo | Greenhouse for plant cultivation |
| CN112544303A (en) * | 2020-12-29 | 2021-03-26 | 呼伦贝尔学院 | Be used for high latitude severe cold district to abandon fire clean energy type double-framework main part greenhouse temperature canopy structure of surviving winter |
| CN112544303B (en) * | 2020-12-29 | 2022-08-19 | 呼伦贝尔学院 | Be used for high latitude severe cold district to abandon fire clean energy type double-framework main part greenhouse temperature canopy structure of surviving winter |
| CN118488779A (en) * | 2021-11-07 | 2024-08-13 | 亚历山大·保罗 | System and method for on-demand insulation between layers of a double layer window |
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