GB2486471A

GB2486471A - Adjustable ventilator for mounting at a roof of a building

Info

Publication number: GB2486471A
Application number: GB1021353.6A
Authority: GB
Inventors: John Walsh; David Brown
Original assignee: MIDTHERM ENGINEERING Ltd
Current assignee: MIDTHERM ENGINEERING Ltd
Priority date: 2010-12-16
Filing date: 2010-12-16
Publication date: 2012-06-20
Anticipated expiration: 2030-12-16
Also published as: GB2486471B; WO2012080736A1; EP2652411A1; GB201021353D0

Abstract

An adjustable ventilator(s) 100 mounted at a roof of a building communicates air between an exterior and interior of the building. The ventilator comprises a plurality of stacked vent blades 202 configured to allow each blade move upwardly and downwardly. Movement upwardly and downwardly is between an extended configuration in which the blades are spaced apart in a vertical direction and a collapsed configuration (fig 6) in which the blades are brought together to reduce the space between the blades in the vertical direction to prevent rain and noise ingress when the ventilator is not in use. Individual blades may be opened sequentially or a linkage may be provided to open all of the blades simultaneously. A gasket (203, fig 3a) may be provided on the trailing edge (301) of the blades. The blades may be thermally insulated, may be hollow defining an internal cavity (801, fig 8) through which a heat transfer fluid flows to prevent freezing of the blades or cool incoming air or contain solid, liquid or gas phase thermal insulation. The blades may be electrically heated (604). The ventilator may be passive or fan assisted (fig 6) and powered by a photovoltaic cell (600).

Description

AN ADJUSTABLE BUILDING VENTILATOR

The present invention relates to a building ventilator comprising a plurality of vent blades that define a stack of louvres in which the vent blades are capable of movement in a vertical direction between an extended configuration in which the blades are spaced apart from one another and a collapsed configuration in which the blades are brought together to reduce the space between them in the vertical direction.

Most buildings designed for high occupancy require a ventilation system to provide both a supply of fresh air to the building interior and to regulate the internal temperature.

Typically, most large commercial buildings use electricity driven air conditioning systems that both circulate air within the building. and provide this internal temperature control.

In response to climate change and restrictions imposed by legislation, national jurisdictions increasingly require a more environmentally friendly ventilator system that provides an enhanced energy rating and a reduced carbon emission rating. Accordingly, natural ventilators have emerged as an attractive alternative to conventional electricity driven air conditioning systems.

Natural ventilation relies on the external wind conditions to deliver the required fresh air supply and typically involve a stack of louvres that sit on top of the building or roof whereby air is capable of flowing through the louvres and into the building interior via ducting positioned below the louvres. As warm air rises and exits the room, via the louvres, a negative pressure is created (in the room) which acts to draw-in an external fresh air supply. The flow of air through the device is further assisted by the windward and leeward pressures exerted on the ventilator by the external wind speed.

GB 2432207 discloses an active stack ventilator arrangement that utilises a fan positioned at the bottom of the ventilator to draw air into the building. The rate by which the air flow is delivered to the receiving room is controlled by mechanical dampers and a static sealing diffuser.

However, conventional natural ventilators are disadvantageous for a number of reasons.

The primary problem is the significant reduction in insulation at the region of the ventilator which typically contains a cold body of air separated from the room interior by the mechanical dampers and sealing diffuser only. Also, the dampers must be continually actuated in order to control the airflow rate to and from the building interior and this is not typically energy efficient.

What is required is a natural ventilator that addresses the above problems and provides an energy efficient means for circulating fresh air.

The inventors provide a natural ventilator for mounting at a roof of a building being a passive, active-passive or active ventilator in which a stack of ventilator blades are capable of moving in the vertical direction relative to one another so as to adjust the spacing between blades and the number of open' louvers through which a stream of air may flow.

This provides accurate control of the rate of airflow into and from the building interior.

This configuration also reduces the volume of cold air within the ventilator body and accordingly improves the thermal efficiency of the ventilation system. Moreover, as the airflow rate is controlled by the relative blade spacing and/or the number of open louvers, the requirement for additional mechanical dampers is avoided.

According to a first aspect of the present invention there is provided an adjustable building ventilator for mounting at a roof of a building, the ventilator comprising: a plurality of vent blades mountable at an external facing region of a frame defining a duct through the roof of a building, the duct configured to convey air between an exterior and an interior of the building; wherein the blades are stacked on top of one another to form a stack of louvres; a blade mount configured to allow each one of the blades to move in an upward and downward direction relative to neighbouring blades and the frame; and an actuator connected to the mount and/or at least one of the blades and operative to move each one of the blades in the upward and downward direction between an extended configuration in which the blades are spaced apart from one another in the vertical direction and a collapsed configuration in which the blades are brought together to reduce the space between the blades in the vertical direction.

Preferably, the ventilator each blade comprises: a leading edge that is external facing relative to the duct and a trailing edge that is internal facing relative to the duct; and a flange extending from the leading edge and orientated transverse to the plane of the blade; and wherein a length of each blade in the horizontal plane increases from the lowest to the highest blade such that when the blades are in the collapsed configuration together the flanges of neighbouring blades overlap in the vertical direction.

Preferably, the ventilator further comprises at least one elongate guide rod, the guide rod allowing movement of the blades in the vertical direction relative to neighbouring blades and the frame. Preferably, each blade is mounted at a guide rod via its trailing edge. More preferably, each blade is mounted at the guide rod via a bushing such that each blade is capable of sliding along the length of the guide rod. Preferably, the ventilator further comprises a sealing gasket mounted at the region of the bushing. Optionally, each sealing gasket comprises a resiliently biased barb upwardly extending and capable for folding downwardly when contacted against an upper neighbouring sealing gasket when the blades are collapsed together. Preferably, each sealing gasket comprises a rubber material.

Preferably, an upward facing surface of each sealing gasket is inclined relative to a horizontal plane.

Preferably, the ventilator further comprises a collapsible mesh extending from the lowest blade to the highest blade of the stack of louvres in the vertical direction and capable of collapsing when the stack of louvres are brought together to reduce the space between the blades in the vertical direction. Optionally, the mesh comprises a deformable material and may comprise a corrugated structure enabling it to collapse and expand along its length.

Preferably, the mesh is positioned at an intemal region of the stack of louvres.

Preferably, the ventilator further comprises at least one blade linkage connecting each blade in the vertical direction such that when an upper blade of the stack of louvres is first actuated to move in the upward direction, a neighbouring lower blade of the stack of louvres is actuated to also move in the upward direction via the blade linkage. Preferably, the blade linkage comprises a plurality of cables connected to each blade. When each blade is coupled via a blade linkage, it is possible to extend the stack of louvres sequentially such that a first louvre is opened without opening other closed' louvres in the stack. Once the blade linkage becomes taught, the next blade is pulled in the upward direction to create and open a second louvre of the stack. This sequential opening and closing of each individual louvre may be controlled manually or automatically and ensures that a minimum number of open louvres are created so as to deliver the required fresh air supply at the building interior. According to further embodiments, the linkage may be configured such that all louvres are opened simultaneously and the spacing between louvre blades is increased simultaneously from a minimum inter-blade separation to a maximum inter-blade separation distance.

Optionally, the ventilator may further comprise a head frame slideably mounted at the blade mount and connected to the actuator such that the actuator is operative to move the head frame in an upward and downward direction relative to the main frame. Preferably, the actuator comprises a piston arrangement operative by pneumatic, hydraulic, electronic or electromagnetic actuation. Optionally, the ventilator further comprises an automated control module operative to provide automated control of the piston arrangement.

Alternatively, the ventilator may further comprise a manual control configured to allow a user to control manually actuation of the piston arrangement.

Optionally, the ventilator may comprise an input andlor extraction fan positioned within the internal regional of the ventilator. The fan may be positioned at any region within the ventilator. Preferably, the fan is positioned within the duct region of the ventilator below the stack of louvres. Alternatively, the fan may be positioned within the region of the stack of louvres in the horizontal plane. Optionally, the fan may be positioned at any region within the ventilator between the internal facing end of the duet, adjacent to the room interior or towards an external facing end of the duct adjacent to the stack of louvres.

Optionally, the ventilator may comprise a roof enclosure extending above the uppermost blade of the stack of louvres in the vertical direction to define a cavity above the stack of louvres.

Preferably, the ventilator comprises a heating assembly to provide heating of the bushings, blade mounts, blades or other mechanical actuation components that provides for movement of the blades in the vertical direction. Such a heating assembly is particularly advantageous where the ventilator is installed in a cold climate to avoid frost damage and to ensure these moving components do not freeze or become hindered from operation by frost or cold temperature seizing. Optionally, the ventilator comprises a reservoir for a heating fluid to circulate in contact with the bushings, blade mounts and/or blades.

Preferably, the reservoir is defined, in part, by each sealing gasket, the ventilator further comprising a heating element to heat the fluid within the reservoir. Optionally, the ventilator may further comprise a heating element connected to the blade mount.

Optionally, the ventilator may comprise at least one collapsible partition extending through the internal region of the stack of louvres in the vertical direction, the partition configured to collapse when the stack of louvres is moved to the collapsed configured to partition the internal space of the ventilator to create separate airflow channels in the vertical direction through the ventilator. Preferably, the collapsible partition comprises an outer mesh frame defining an elongate duct, the mesh frame allowing the through flow of air; and at least one internal wall extending within said elongate duct to partition the internal space of said elongate duct along its length.

Preferably, the ventilator comprises an airflow assistance fan positioned within the internal region of the ventilator. This fan is optionally powered by a photovoltaic cell, optionally via intermediate battery supply.

Optionally, the ventilator may further comprise a weather sensor positioned at an external region of the ventilator, the weather sensor being coupled to an automated control module such that the ventilator may be configured to be responsive to the external weather conditions and to increase or decrease the distance between blades to open and close the stack of louvres by movement in the vertical direction.

According to second aspect of the present invention there is provided an array of adjustable building ventilators for mounting at a roof of a building, each ventilator of the array comprising: a plurality of vent blades mountable at an external facing region of a frame defining a duct through the roof of a building, the duct configured to convey air between an exterior and an interior of the building; wherein the blades are stacked on top of one another to form a set of louvres; a blade mount configured to allow each one of the blades to move in an upward and downward direction relative to neighbouring blades and the frame; and wherein the blades are moveable in an upward and downward direction between an extended configuration in which the blades are spaced apart from one another and a collapsed configuration in which the blades are brought together to reduce the space between the blades in the vertical direction.

Preferably, the ventilator may further comprise at least one actuator connected to the blade mount and/or at least one of the blades and operative to move the blades of each ventilator of the array in the upward and downward directions.

Preferably, the ventilator further comprises a motion or pressure sensor configured to sense any resistance to linear movement of the blades from the open to the collapsed state due to, for example, fingers or other obstructions placed between the blades. The ventilator further comprises means to arrest movement of the actuator in response to a signal from the sensor that an obstruction is present between the blades. Such sensing and auto shut-off apparatus comprises known components and construction as will be appreciated by those skilled within the art.

Preferably, the ventilator may further comprise: a master room controller; at least one external building sensor being at least one of a temperature, rain/snow, wind, noise and/or air quality, particulate, and/or humidity sensor; and a power supply. Optionally, the ventilator may further comprise a building energy management system coupled electronically with the master room controller. Optionally, the ventilator may further comprise a time clock. Optionally, the ventilator may further comprise a signal conditioning unit.

According to a third aspect of the present invention there is a building comprising a ventilator or an array of ventilators as described herein.

A specification implementation of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which: figure 1 illustrates a roof of a building comprising an array of ventilators according to specific implementation of the present invention; figure 2 illustrates a cross sectional side elevation view of a ventilator in which the blades of the stack of louvres are collapsible in the vertical direction relative to one another according to a specific implementation of the present invention; figure 3A is a side elevation view of a blade and means for mounting the blade at a blade mount of figure 2; figure 3B is a side elevation view of a blade and mounting of figures 2 and 3a; figure 4 is a plan view of the head frame illustrated in figure 2; figure 5A is a cross sectional side elevation view of a further embodiment of the ventilator of the present invention comprising an alternate form of internal barrier mesh illustrated in figure 2; figure SB is a cross sectional side elevation view of a further embodiment of the collapsible mesh frame of figure 5A; figure 6 is a cross sectional side elevation view of the ventilator of figure 2 in a collapsed configuration in which a spacing between the blades is reduced from the spacing illustrated in figure 2; figure 7 illustrates schematically a collapsible partition duct extending within the stack of louvres and partitioning the internal space of the ventilator to create separate air flow channels in the vertical direction according to a specific implementation; figure 8 illustrates a side elevation view of a further embodiment of the stack of louvres in which the blades comprise an intemal hollow region to accommodate a heating fluid; figure 9 illustrates a side elevation view of the ventilator of figure 2 according to a further specific implementation in which vertical movement of the louvres is provided by a plurality of actuators mounted at the perimeter or outside region of the internal space of the louvers stack; figure 10 illustrates schematically electronic components of a control system for the ventilator of figures 1 to 9; and figure 11 illustrates the various power supply systems for the electronic components of figure 10.

Referring to figure 1, the natural ventilator 100 is configured for positioning at a roof 102, on a building 101. The ventilator 100 comprises a roof enclosure 105 positioned above a stack of louvres 103. The louvers 103 are mounted above a frame 104 that defines a duct extending between an extemal region of the building 101 and the interior of the building.

The present ventilator is capable of functioning as a standalone, independent unit or forming part of an array of ventilators as illustrated in figure 1.

Referring to figure 2, the ventilator comprises a set of vent blades 202 stacked above one another in the vertical direction to define the stack of louvres 103. Figure 2 illustrates the ventilator with the blades 202 in an expanded configuration in which a spacing d' is a maximum. The altemate collapsed configuration is illustrated with reference to figure 6 in which the relative blade separation distance d' is much reduced.

Each blade 202 is mounted at a common elongate guide rod 204 via mountings 203. Each mounting 203 is capable of sliding lengthwise along guide rod 204 in the vertical direction relative to the stack of louvres 103 and the elongate duct 104 positioned immediately below the stack of louvres 103.

The ventilator comprises four guide rods 204 equally spaced apart at the perimeter region of the stack of louvres 104. In plan view, the stack of louvres 104 may comprise a square, rectangular, oval or circular profile. If square or rectangular, a guide rod 204 is positioned at each eomer of the louvres. Each guide rod 203 is secured at an upper region 200 of the duct frame 104 by suitable nut and bolt type fixings. Each guide rod 204 is secured at its upper end to a head frame 205 illustrated with reference to figure 4. Head frame 205 comprises a wheel-like configuration in which a circular perimeter section 401, is bisected by four radial spokes 400 that extend from a central boss 402. Accordingly, guide rods 204 are maintained in a fixed configuration between duct frame 104 and head frame 205 to form a structure sufficiently rigid to resist wind sheer with little or no undesired bending, twisting or flexing of the ventilator 100. Additionally, the ventilator comprises a lower head frame 211 extending across the internal region of the duct 104 that is aligned in the horizontal plane substantially parallel with the upper head frame 205. The lower head frame 211 comprises a similar/identical shape and configuration as upper head frame 205 and further increases the structural rigidity of the ventilator 100.

The ventilator further comprises a mesh 212 extending along the length of the stack of louvers 103 in the vertical direction from a lower mounting region 214 of the duct frame 104 to an upper mounting region 215 at the head frame 205 positioned above the stack of louvres 103. Accordingly, mesh 212 extends a distance beyond the uppermost blade 217 and a lowermost blade 216 of the stack of louvers 103 so as to completely partition an internal region of the ventilator 207 and an external region 218. A size or gauge of the mesh 212 is selected to provide an entry barrier for birds and vermin that may pass between the blades 202. An appropriate gauge for mesh 212 may be 10 x 10 mm.

According to the specific implementation of figure 2, mesh 212 is positioned at the internal region 207 of the stack of louvers 103 and is formed from a deformable material such as a synthetic polymer material including, for example Nylon.

Each blade 202 is connected to its neighbouring blades in the upper and lower direction via a cable linkage 213. Linkage 213 serves to provide a mechanical link between blades 202 such that movement of an upper blade 217 provides a corresponding movement of a lower blade of the stack 103 as linkage 213 is pulled and becomes taut. Each inter-blade linkage 213 may comprise a flexible wire or cabling formed from a synthetic polymer material or a metal alloy such as steel.

Movement of each blade 202 in the vertical direction is provided by an actuator 206.

According to the specific implementation, actuator 206 comprises a motor 209 that is operable to push and pull a piston rod 208 to and from a housing 218. Actuator 206 is mounted at lower head frame 211 and is therefore stationary and rigidly mounted at duct frame 104. A distal end of piston rod 208 is connected to the central boss 402 of head frame 205 such that actuation of rod 208 in the upward and downward direction provides a corresponding movement of the head frame 205. Each uppermost blade 217 of the stack 103 is fixably attached to head frame 205 such that movement of frame 205 in the vertical direction provides a corresponding movement of each blade 217.

Figure 6 illustrates the ventilator of figure 2 in a collapsed configuration in which the piston rod 208 has been retracted fully into piston housing 218 to draw the head frame 205 towards lower head frame 211 and accordingly collapse the louvre stack 103 to ultimately reduce the spacing d' between blades 202. In this configuration mesh 212 is collapsed inwardly within louvre interior 207. As illustrated in figure 3A, each blade 202 comprises a leading edge 300 an a trailing edge 301. A flange 302, 303 extends respectively from the leading edge 300 and trailing edge 301. Each flange 302, 303 is aligned transverse to the main length of the blade 307. In order to collapse on top of one another, as illustrated in figure 6, a length e' of each blade shaft 307, in the horizontal plane, increases from the lowermost blade 216 to the uppermost blade 217. As illustrated in figure 6, each flange 302 at each leading edge 300 is therefore capable of overlapping flanges 302 of neighbouring blades 202 so as to completely seal and partition the internal region of the ventilator 207 from the external region 218. This configuration prevents rain and noise ingress into the ventilator interior. Additionally, the roof enclosure 104 extends over the flange 302 of the uppermost blade 217 at the region 601. Similarly, flange 302 of lowermost blade 216 is designed to overlap a shoulder 210 extending from an upper region of the duct frame 104 to ensure water ingress into the ventilator interior 207 is prevented.

Accordingly, blades 202 are configured to move with respect to one another and duct frame 104 so as to vary the respective blade separation distance d'. In the collapsed configuration of figure 6, a smaller volume of cold air is housed within the reduced internal volume 207 compared to the expanded configuration of figure 2 so as to reduce any cooling effect provided by the ventilator at the building interior. In order to improve the thermal efficiency and prevent cold bridging, insulation 605 may be provided at roof enclosure 105 and an inner layer of insulation 606 may be provided at duct 104 in addition to an outer layer 607 extending from a region of the louvres 103 to the roof 104. According to a specific embodiment blades 202 may comprise thermal insulation provided around the blade body. Alternatively insulation may be provided on an upper or a lower face only.

The main length 307 of each blade 202 is inclined relative to the horizontal at an angle in the range 30° to 45°. Additionally, the available range of the distance d' in the vertical direction between adjacent blades 202 may be 0 mm to 500 mm. Additionally, the maximum distance d' may be 20 mm to 60 mm, 20 mm to 35 mm, 27 mm to 33 mm or may be around 30 mm according to a specific embodiments.

Referring to figures 3A and 3B, each blade 202 is mounted at guide rod 204 via an aperture 308 extending through flange 303 at the blade trailing edge 301. To allow each blade 202 to slide lengthwise along the length of the elongate rod 204, a bushing 307 is positioned at aperture 308 and is held in place by a sealing gasket 203. Each bushing 307 is formed from a solid or hollow disc-like body having a through bore of a diameter corresponding to the diameter of the guide rod 204. Sealing gasket 203 is formed from a deformable material such as rubber and is capable of deforming under compressive forces as the stack of louvres is collapsed and the sealing gaskets 203 compress against one another in the vertical direction as illustrated in figure 6. An upstanding resiliently biased barb 303 projects from one end of the sealing gasket 203 closest to the internal region of the ventilator 207. The barb 304 is capable of folding downwardly towards uppermost surface 306 when a neighbouring sealing gasket is moved in a downward direction. The upper surface 306 of sealing gasket 203 is inclined relative to the horizontal. Accordingly, as an upper blade and gasket assembly 309 is moved towards lower blade assembly 310, the lower face 311 of gasket 203 contacts barb 304 to bend it downwardly against surface 307.

Any water accumulated at the sealing gasket 203 is then allowed to drain from the sloping surface 306, onto the sloping surface of the main blade length 307 away from the ventilator interior 207.

The annular bushing 307 may comprise a material such as Teflon or nylon having a smooth internal bore so as to readily slide over the outer surface of guide rod 204.

So as to avoid the moving components of the ventilator 100 seizing due to frost, a heating assembly 604 is provided so as impart a heating effect to the moving components such as each blade 202, bushing 307, sealing gasket 203, guide rod 204, head frame 205 andlor actuator 206. Heating assembly 604 includes at least one electrically operated heating element positioned in direct or indirect contact with any one or a combination of these moving components. In one embodiment, the heating element may be connected directly to each guide rod 204 such that thermal conduction through the guide rod 204 is sufficient to heat bushings 307 and sealing gasket 203 to avoid freezing at low temperatures. According to further embodiments, selected components such as the guide rod 204, bushing 307, sealing gasket 203 and/or blades 202 (detailed at figure 8), may comprise a hollow configuration so as to define an internal reservoir capable of accommodating a heat transfer fluid. Such a heat transfer fluid would then be connected in fluid communication with the heating assembly 604 such that a circulated heated fluid would be capable of flowing through the selected moving components of the ventilator. The heating assembly 604 may be mains or battery powered and comprise a suitable thermostat or other means of regulating the temperature of the heating element and/or any transfer fluid.

Figure 5A illustrates an alternative embodiment for positioning of the partitioning mesh 202 illustrated in figure 2. According to the further embodiment, mesh 500 is formed as a concertina or corrugated elongate structure with the first end 507 attached to frame 104 and a second upper end 507 attached to head frame 205. Intennediate regions 502, 501 between the first and second ends 507, 506 are configured to bend or flex as blades 202 are expanded and collapsed relative to one another between the configurations of figures 2 and 6. In particular, mesh 500 may be additionally attached at regions 502 to respective sealing gaskets 203 to ensure the mesh folds and unfolds as desired when the blades 202 are moved. Mesh 500 is positioned at the internal region 207 of the louvres stack 103.

Figure SB illustrates a further embodiment for positioning of the partitioning mesh described with reference to figures 2 and SA. In the further embodiment, the mesh 509 is positioned at an external region 218 of the stack of louvres 103. In particular, mesh 509 extends between flanges 302 provided at the leading edge 300 of each blade 202. As with the embodiment of figure 5A, mesh 509 is designed to fold at discrete regions 503 and 504.

Complete partitioning of the internal region of the louvre 207 an external region 218 is provided as mesh 509 is attached at its lowest most end 508 to shoulder region 210 and at its uppermost end 505 to roof enclosure 105.

Figure 7 illustrates an optional internal partitioned duct 706 that may be accommodated within the internal region 207 and 201 extending from the region of the louvres 103 towards the innermost end of duct 104 adjacent to the room of the building 101. The collapsible duct 706 comprises an outer duct wall 700 being formed from a mesh material that allows a through flow of air to and from an internal region of the duct 706. This duet is partitioned along its length by radial partitioning walls 702 to define elongate airflow channels 703, 704 extending the length of duct 706.

Both the duct wall 700 and the internal partitions 702 are formed from a material that is flexible and may be collapsed as the stack of louvres 103 is collapsed from the configuration of figure 2 to that of figure 6. Tn particular, folding regions 705 extend the length of duct 706 allowing it to fold in a concertina manner in its axial direction. That is, both the outer duct wall 700 and the partition walls 705 are configured to fold at regions 705 so as to reduce the overall length of the duct 706. Walls 700, 705 may be formed from a woven fabric or a fine mesh of a synthetic polymer or metal alloy.

Optionally, the ventilator 100 may include a fan assembly 602 mounted within the internal region 207, 201. The fan comprises a plurality of axially rotatable fan blades 603 that may be operated in one or two directions so as to provide means to drive an airflow stream into the ventilator and the building interior andlor in an alternate mode of operation to assist with stale air extraction by operation in a reverse plurality to expel stale air through the spacing between blades 202. Fan assembly 202 is powered by a suitable photovoltaic cell 600 mounted at roof enclosure 105. Alternatively, the fan assembly may be powered by mains or a battery supply. Additionally, actuator 206 may be powered by photovoltaic cell 600.

In use, when a supply of fresh air is required and/or stale air is required to be exhausted from an internal room of building lOt, piston rod 208 is actuated to push head frame 205 in an upward direction from the collapsed configuration of figure 6. Head frame 205 then slides ilong the length of the four guide rods 204. As the uppermost louver blade 217 is attached to head frame 205, it is pulled in the upward direction with the movement of piston 208. Via linkage cables 213, the second highest louvre blade is then also pulled upwardly as the linkage 213 becomes taught. This sequential opening of the louvre blades proceeds until all the blades of stack 103 are lifted from the collapsed configuration of figure 6 to the fully open configuration of figure 2. If a user requires little or modest ventilation, the rod 208 is actuated to lift only some and not all of the blades from the collapsed configuration of figure 6. Of course, this can be controlled automatically in response to thermostat settings such that the ventilator may be opened to create a louvre stack formed from only two blades up to a maximum opening where all blades are separated from one another in the vertical direction as shown in figure 2. According to further embodiments, the mechanism for opening the stack of louvres may comprise an alternate rack and pinion configuration such that the spacing between all blades is increased simultaneously and not in series according to the cable linkage as described herein.

In the fully collapsed configuration of figure 6, the overlapping flanges 302 together with the deformable sealing gaskets 203 provide a complete seal of the internal louvre stack 207. This greatly increases the thermal insulation efficiency of the ventilator when not in use.

According to a further embodiment, actuator 206 may be housed at a region outside or at the very perimeter of the internal louvre space 207. In particular, at least one of the guide rods 204 may be configured as an actuator so as to displace head frame 205 up and down, According to the embodiment of figure 1, where a plurality of ventilators are mounted at a roof space 102, each ventilator may form part of an interconnected set in which the respective louvres are moved by at least one common actuator connected to each louvres stack by suitable mechanical linkages.

Referring to figure 6 and figure 8, to prevent seizing of the moving components and in particular the sliding of the blades relative to the guide rods 204, a heating fluid may be acconnnodated within each blade 800. That is, each blade 800 comprises an internal cavity 801 to accommodate the fluid. Suitable ducting may then be provided so as to connect each blade to the fluid reservoir 604 and the heating element. The heating fluid may also be configured to flow within the sealing gaskets 203 and optionally the guide rods 204.

According to further embodiments, cavity 801 may be filled with a thennal insulation material being a solid, liquid or gas phase material (not shown). Additionally, the present device may be configured to house a cooling fluid within cavity 801 where fluid reservoir 604 is fitted with suitable refrigeration components so as to provide a cooling effect to the air as it passes in contact with blades 800 into the ventilator interior 207.

Figure 9 illustrates a further embodiment in which the ventilator comprises a plurality of linear actuators 206 positioned at or towards the perimeter of the internal space 207 of the stack of louvres. In particular, four linear actuators may extend from the head frame 205 and are connected thereto at mating points 204 as shown in figure 4. The embodiment of figure 9 illustrates the optional use of non-cavity blades 202 or blades 800 having an internal cavity to accommodate a heating fluid. Positioning the linear actuators 206 at the outer regions of the internal chamber 207 may improve the desired airflow characteristics for certain ventilator designs including circular, square, rectangular or oval head frame geometries. According to further embodiments, rotary actuators (not shown) may be used in place of linear actuators 206 to provide upward and downward movement of head frame 205 and blades 202, 800.

A particular feature of the present ventilator system is that it allows for the use of the ventilators 100 as a natural or natural-passive device via roof mounted low power drive actuators 206. When used in the passive or natural ventilation mode input or extract ventilation air is driven primarily by wind pressure alone, coupled with positive and negative pressure airflow effects within the building space below.

The vertical movement of the external louvers stack 103 provides control of the airflow path into and out of the building space below. In particular, the vertical movement of the low powered actuators 206 determines the overall fully open and fully closed set point positions of the roof ventilator louvers 202.

Heat reclamation or fresh air normalisation is known within the air movement industry.

However conventional systems require a plenum or casing to mix stale and fresh air together, with at least two controlled low powered fans to drive air into and out of the mixing system, as well as a bank of filters for filtering of the mixed air that is then pushed back into the building structure. These systems offer extremely reduced natural or passive stack capability due to the system configuration and air filters which create resistance to airfiows.

The purpose of fresh air equilibration at internal spaces is to provide a fresh air input whilst maintaining a comfortable room temperature. This provides saving on heating energy costs during the heating season. The design and implementation of most air normalisation units primarily involves taking-up large spaces within roof voids to accommodate the tO required plenums, mixing chambers, fans and associated ducting. In some cases condensate drain points are required to drain away the condensation caused by the mixing of cold and warm air flows within the main chamber area. The airfiows through equilibration units tend to only accommodate for their use during the heating season where lower ventilation rates are required during winter operation. This puts constraints on the systems usage due to the small low powered fans being unable to provide the required higher airflow rates for summer operation, where higher airfiows and cooling rates are required to meet with building codes and regulations and occupancy demand whilst providing a natural cooling effect. This cooling may be achieved via greater powered fan units but this would in turn increase the demand for energy and be counterintuitive as part of the design of the whole system.

A particular feature of the present ventilator 100 is that it allows for the use of the ventilators 100 as effective air dilution system to be used during winter mode operation.

The principal is the reverse of conventional air dilution system in as much as the system will dilute CO2 laden air from within the building with fresh oxygen from roof level and return the air as low CO2 laden air to the space below. This principal helps the internal environment by reducing the overall effects of CO2 within the space whilst further reducing the amount of CO2 given off to atmosphere.

The present system may be used not only as natural input and extract ventilator with low powered boost fan 602, but as a simple heating or cooling air dilution system. Furthermore the present ventilator 100 provides a simple dilution air system that does not require large plenums for mixing of air, containment of multiple fans or filters and that they can be precisely controlled primarily upon optimal internal and external climatic condition set points.

The use of the actuator driven louvers 202 in conjunction with duct 104, a low powered fan 602 and a damper (not shown) located at the ceiling interface, contribute to making the present invention a contained multi purpose' ventilation, fresh air equilibration and air dilution system. The method of control for the various ventilation options is dependent on the particular ventilation design. For example, a particular building application would ultimately determine the overall controls configuration and set point parameters required to control each operational feature at its optimal performance level.

Precise operation and control of the low powered fans 602 is important to the actuator driven roof terminal design in that the fans 602 must operate at various set point parameters primarily in conjunction with varying external and internal climatic conditions.

The fan 602 may activate at any time when the roof terminal louvers 103 are in an open, partially open, partially closed or fully closed state. This again is dependant upon internal and external climatic conditions. The low powered fans 602 are speed controlled through signal conditioning units according to specific set point conditions, and only activated when they are required to do so via signals from climatic sensors 1004a to 1 004h. In particular, the low powered fans 602 are activated only when the wind speed is insufficient to ventilate the building space naturally.

Precise control of the louver spacing d' is also important in that dampening of the louvers stack 103 can be responsive to the effects of wind speed and direction, precipitation and varying noise levels. This method of control will limit the louvre openings by way of control signals to the drive actuators 206 and will move the louvers 202 according to set point conditions from either the a master controller 1000 or a building energy management system 1007. This form of control will limit the amount of natural wind, noise and precipitation that may be entrained into the internal building space by limiting louvre spacing d' at roof level.

The control methodology and control parameters of the actuators 206 and fan units 602 is important to provide optimal performance levels of the ventilator 100 when operating in the various different modes including natural-passive or natural ventilation, heat reclamation and air dilution.

Figures 10 and 11 detail the electronic control management components of the present invention configured to control actuation of the actuators 206 and in turn the opening and closing of the louvers stack 103. Operational control of the fan units 602 is also provided and integrated with control of the actuators 206. According to a specific implementation, the electronic control system comprises a master room controller 1000; wiring centre 1002; carbon dioxide sensor 1003; air quality sensor 1004a; noise sensor 1004b; wind sensor 1004c; rain/snow sensor lOO4d; external temperature sensor 1004e; blade separation sensor 1004f; humidity sensor 1004g; particulate sensor lOO4h; internal temperature sensor 1005; heating/cooling signal 1006; building energy management system 1007; stand-alone time clock zone 1008; low powered drive actuators 206; signal conditioning unit 1010; low powered fans 602; AC power supply lOl2a; solar or DC power supply l0l2b; solar power layout l0l2c; and in-duct temperature sensor 1013 and; internal humidity sensor 1014.

Additionally, the present control system further comprises: solar array 1100; solar charge controller 1101; battery bank 1102; solar trickle charger 1103; time clock or switched relay via BEMS 1104; and digital battery charge level indicator 1105.

The optimal control of the actuators at the roof level ventilator or ventilators is important to the overall system design. The driven actuators 206 must open and close in proportion to internal, as well as external climatic conditions as well as dampening the units from varying external noise and rain/snow. The control system will ensure that the optimal levels of air input and extraction are maintained during all seasons especially in relation to noise and rain/snow levels via externally mounted sensors 1004a to 1004h. Sensor 1004f comprises a motion or pressure sensor configured to sense any resistance to linear movement of the blades 202 from the open (figure 2) to the collapsed (figure 6) state due to fingers or other obstructions placed between the blades. Sensor lOO4f is coupled electronically to the management system 1007 and/or master room controller 1000 such that in response to a signal from sensor 1 004f any further closing' movement of actuator 206 is stopped and/or reversed via the system 1007 andlor controller 1000. The roof ventilator dampening arrangement is provided by the actuator drives 206 which controls the openings d' between louvers 202. Optimal control of the actuator drives 206 is further dependant upon seasonal weather changes ie. wind, rain and temperature fluctuations. The master room control system 1000 will limit the actuator drives 206 pre determined set points for high wind rn/s or mph, continuous rain, snow fall or particulate/sand storm and external temperature conditions based upon readings from external sensors 1 000a to 1004h.

The control system is responsive to external climatic changes whilst maintaining a comfortable (set point) internal temperature, humidity and carbon dioxide level for the building occupants. Temperature, humidity and carbon dioxide levels are monitored through internally mounted temperature 1005, humidity 1014 and carbon dioxide 1003 sensors. In particular, monitoring the humidity, for example, externally and internally allows the control system 100 to balance or normalise fresh air received into the ventilator duct 207 before it is delivered into the building interior. This is provided by closing primary or secondary dampers (not shown) positioned at the interface with the building interior (room) and the innermost region of the duct. Once fresh air has been equilibrated (heated or cooled for example) to the desired level, the dampers may be opened to allow the air to be delivered into the room space below. Alternatively the dampers may be pulsed for second or minute intervals to provide a controlled flow of normalised fresh air into the interior.

The low powered fan units 602 may be used to boost airflow input and/or extraction.

Accordingly, control of the units 602 is linked to the internal room conditions and regulation of the fan speed is provided via signals from signal conditioning unit 1010.

The fan control (via signal conditioning unit 1010) is linked to the positioning of the drive actuators 206 to ensure that the ventilation louvers 202 are firstly open and secondly open in proportion to the fan speed. The signal conditioning unit 1010 takes the wiring centre 1002 damper output control signal (that is controlled via an internal and external climatic sensor i.e. a 0-l0v signal input) and sends out an adjustable fan speed setting in proportion to the set point sensor readings i.e. 0-lOv or PWM. This method of control ensures the ventilator 100 can deliver fresh air or extract stale air without the need (initially at least) for the low powered fans 602 to be operative. This in turn provides an energy usage saving for the overall ventilation system. The fan speed is primarily controlled proportionally via temperature 1005 and carbon dioxide 1003 levels within the spaces to be ventilated. As temperature and carbon dioxide levels rise within the building space the low powered fan 602 will proactively react and either boost air input or extraction at the internal spaces proportionally to the set points relative to the space to be ventilated and only if natural ventilation of the space is not possible due to external wind speed.

The control system 1000 has seasonal e.g., summer' and winter' operating modes and a different set of set point values will apply for each season. Alternatively these set points can be adjusted via a building energy management system 1007. Generally the ventilation levels according to most building codes and regulations are far greater in summer than in winter. This is due to the need for higher air change rates and cooling effects. Winter air changes are generally lower due to the need to retain heat within the building space and conservation of heat energy at the internal space is most critical.

For example, master controller 1000 in summer' operation allows maximum permissible airfiows by way of the room mounted sensors 1004a to 1004h. To ensure that draughts to the internal spaces from high winds arc minimised, the wind speed sensor 1 004c sends a signal to the master room controller 1000 or building energy management system 1007 to limit the actuators 206 to dampen the ventilator louvers 202 according to the appropriate set point conditions.

The master controller 1000 is linked to the building's heating system 1006 either directly to the room master controller 1000 or via a building energy management system 1007 to modulate the room temperature and ventilation system according to the adjustable set point positions. The master controller 1000 monitors the internal temperature, humidity and carbon dioxide levels within the space and either calls for ventilation, heating or cooling dependant upon the demand set points. A dead zone' set point between heating requirement and ventilation/cooling requirement will be set between 1°C and 2°C to avoid conflicts with system for example.

The master controller 1000 comprises an adjustable winter' set point position to limit the actuators 206 for winter conditions. This set point position is set between the ranges of 15% and 35% maximum open drive position for the actuator drives 206. This will assist in minimising heat losses from the building interior whilst the buildings heating systems are operative. Furthermore, the winter ventilation rates set by building codes and regulations will be maintained through variable set point adjustment. With the master controller 1000 set to the winter' position it will also be possible to use the ventilator internal duct as a mixing chamber to provide normalisation of fresh air received into the duct 201 from outside before it is delivered into the building interior. The principal being that heat rising to the internal ceiling level will fill the sealed insulated ducting space 201 and act as a heat holding chamber. As the internal ducting is effectively an open face at the ceiling and the ventilator 100 is sealed and insulated whilst the actuator drives 206 are at fully closed position as detailed in figure 6, the warm heated air within the ducting space 201 and louvers space 207 will be pushed gently back into the rooms via the low powered fans 602 whilst the actuators 206 at roof level are maintained in a closed position. This will assist the heating system in having to maintain a stable temperature, humidity and carbon dioxide level within the space via this air equilibration process. The air equilibration will be controlled via in-duct mounted sensor 1013, and room sensors 1003, 1005 and 1014. When the internal space of the insulated ducting is at a suitable set point temperature the fan 602 will be activated via the master controller 1000 or suitable building energy management system 1007 and its speed adjusted to a lowest fan setting to gently push the equilibrated air back into the space below.

The master controller 1000 set point is primarily dependant upon the internally mounted temperature sensor 1005 and the externally mounted temperature sensor 1004 readings.

During winter, it will be possible to use the ventilation system as a effective free' air dilution system to mix untreated CO2 laden air with high 02 content external air, whilst still maintaining a comfortable internal climatic condition for the building occupants. This is possible by determining the winter condition room master controller 1000 set point to operate the drive actuators 206 to a low limit set point and switch the low powered fan 206 to the lowest fan speed setting. The fan 602 will draw in fresh air' from the external environment via the open louvre position, dependant upon the external temperature conditions read from the external temperature sensor 1 004e. Generally the external set point to activate air dilution must be within 5°C of that of the internal climate, and the internal conditions determined by internal temperature 1005 and carbon dioxide sensor 1003. This will mix the fresh' external air with the untreated air from within the building space, and effectively push the mixed air from the chambers 201, 207 back into the space below. The mixing of the combination of temperature controlled air from within the building space with the temperature controlled external fresh' air will maintain lower CO2 levels within the building space during winter periods whilst maintaining a comfortably heated internal space. This method of control may limit the need for ftirther supplementary trickle ventilation systems and furthermore maintain a comfortable temperature level for the building's occupants, whilst continuously limiting the overall carbon emissions from the building's occupants during winter conditions.

A noise level meter 1 004b mounted externally at roof level will influence the drive actuators 206 to open or close proportionally to the building's external noise levels and to the given set points within the master controller 1000 or via building energy management system 1007. This method of control is particularly useful in areas that require natural ventilation but the noise levels throughout any given time period are of a fluctuating type.

The noise level meter lOO4b will be operative predominantly whilst the master room controller is set to summer' operation. As within the winter' operation, the drive actuators 206 are primarily already in a low limit set point condition. Whilst within the summer' set point condition the drive actuators 206 are allowed to drive to the fully open position. This will assist airflows into the building space below. However, it will also allow external noise to pass through the ventilator 100 and insulated ducting lO4at high level. Accordingly, the noise level set point will not close the drive actuators 206 unless the noise level limit set point has been surpassed for an adjustable set point time limit or maximum set point threshold.

The power supply to the fan 603 may be from either an AC mains power supply lOl2a or a DC low power supply lOl2b. In the case of DC low power this may be provided through a power supply unit that converts internally an AC input current to a DC output current as will be appreciated by the skilled person. This will reduce the amount of building energy consumption through use of low power input to electrical equipment.

Where a DC power source is used to power the either the low powered fan 602 or the low powered actuators 206 a suitably sized array 1100 of solar power panels 600 will be used to charge a suitably sized solar battery pack 1102, to provide a primary power source to the electrical equipment.

When solar power and batteries 1102 are selected as a primary source of power for the fan 603 and actuators 206 the control system will include a fully programmable time switch 1104 that is capable of being programmed via software according to world location and time zones, as well as providing for automatic summer and winter time updates. The time switch will switch mains power to a solar AC to DC trickle charger 1103 and only consume mains electricity during off-peak electricity which is generally cheaper. Solar power trickle battery charging during daytime hours will be controlled via an installed solar charge controller 1101 and take direct power from solar array 1100 or the battery bank 1102.

Alternatively, the solar battery trickle charger 1103 may be switched via building energy management system 1007 and a simple relay switch 1104. A DC powered digital battery charge level indicator 1105 is provided so that the building occupants can see the battery state from within the building and recognise when the battery may require maintenance or replacement. The charge indication unit is remote or has a common connection to building energy management system 1007 via relay to control trickle battery charging through various time and energy set point parameters.

Claims

Claims: I. An adjustable building ventilator for mounting at a roof of a building, the ventilator comprising: a plurality of vent blades mountable at an external facing region of a frame defining a duct through the roof of a building, the duct configured to convey air between an exterior and an interior of the building; wherein the blades are stacked on top of one another to form a stack of louvres; a blade mount configured to allow each one of the blades to move in an upward and downward direction relative to neighbouring blades and the frame; and an actuator connected to the mount and/or at least one of the blades and operative to move each one of the blades in the upward and downward direction between an extended configuration in which the blades are spaced apart from one another in the vertical direction and a collapsed configuration in which the blades are brought together to reduce the space between the blades in the vertical direction.
2. The ventilator as claimed in claim 1 wherein each blade comprises: a leading edge that is external facing relative to the duet and a trailing edge that is internal facing relative to the duct; and a flange extending from the leading edge and orientated transverse to the plane of the blade; and wherein a length of each blade in the horizontal plane increases from the lowest to the highest blade such that when the blades are in the collapsed configuration the flanges of neighbouring blades overlap in the vertical direction.
3. The ventilator as claimed in claim 2 further comprising at least one elongate guide rod, the guide rod allowing movement of the blades in the vertical direction relative to neighbouring blades and the frame.
4. The ventilator as claimed in claim 3 wherein each blade is mounted at a guide rod via its trailing edge.
5. The ventilator as claimed in claim 3 or 4 wherein each blade is mounted at the guide rod via a bushing such that each blade is capable of sliding along the length of the guide rod.
6. The ventilator as claimed in claim 5 further comprising a sealing gasket mounted at the region of the bushing.
7. The ventilator as claimed in claim 6 wherein each sealing gasket comprises a resiliently biased barb upwardly extending and capable for folding downwardly when contacted against an upper neighbouring sealing gasket when the blades are collapsed together.
8. The ventilator as claimed in claim 7 wherein each sealing gasket comprises a rubber material.
9. The ventilator as claimed in claim 8 wherein an upward facing surface of each sealing gasket is inclined relative to a horizontal plane.
10. The ventilator as claimed in any preceding claim further comprising a collapsible mesh extending from the lowest blade to the highest blade of the stack of louvres in the vertical direction and capable of collapsing when the stack of louvres are brought together to reduce the space between the blades in the vertical direction.it. The ventilator as claimed in claim 10 wherein the mesh comprises a deformable material.12. The ventilator as claimed in claim 10 wherein the mesh comprises a corrugated structure.13. The ventilator as claimed in claim 10 wherein the mesh is positioned at an internal region of the stack of louvres.14. The ventilator as claimed in any preceding claim further comprising at least one blade linkage connecting each blade in the vertical direction such that when an upper blade of the stack of louvres is actuated to move in the upward direction, a neighbouring lower blade of the stack of louvres is actuated to also move in the upward direction via the blade linkage.15. The ventilator as claimed in claim 14 wherein the blade linkage comprises a plurality of cables connected to each blade.16. The ventilator as claimed in preceding claim further comprising a head frame slideably mounted at the blade mount and connected to the actuator such that the actuator is operative to move the head frame in an upward and downward direction relative to the main frame.17. The ventilator as claimed in any preceding claim wherein the actuator comprises a piston arrangement operative by pneumatic, hydraulic, electronic or electromagnetic actuation.18. The ventilator as claimed in claim 17 further comprising an automated control module operative to provide automated control of the piston arrangement.19. The ventilator as claimed in claim 17 comprising a manual control configured to allow a user to control manually actuation of the piston arrangement.20. The ventilator as claimed in any preceding claim further comprising an input and/or extraction fan positioned within the internal regional of the ventilator.21. The ventilator as claimed in claim 20 further comprising a photovoltaic cell to provide power to the fan.22. The ventilator as claimed in any preceding claim further comprising a roof enclosure extending above the uppennost blade of the stack of louvres in the vertical direction to define a cavity above the stack of louvres.23. The ventilator as claimed in any preceding claim further comprising a heating assembly to provide heating of the bushings andlor blade mount.24. The ventilator as claimed in claim 23 further comprising a reservoir for a heating fluid to circulate in contact with the bushings.25. The ventilator as claimed in claim 24 wherein the reservoir is defined, in part, by each sealing gasket, the ventilator further comprising a heating element to heat the fluid within the reservoir.26. The ventilator as claimed in any one of claims 23 to 25 further comprising a heating element connected to the blade mount.27. The ventilator as claimed in any preceding claim further comprising at least one collapsible partition extending through the internal region of the stack of louvres in the vertical direction, the partition configured to collapse when the stack of louvres is moved to the collapsed configured to partition the internal space of the ventilator to create separate airflow channels in the vertical direction through the ventilator.28. The ventilator as claimed in claim 27 wherein the collapsible partition comprises an outer mesh frame defining an elongate duct, the mesh frame allowing the through flow of air; and at least one internal wall extending within said elongate duct to partition the internal space of said elongate duct along its length.29. The ventilator as claimed in any preceding claim further comprising: a master room controller; at least one external building sensor being at least one of a temperature, rainlsnow, wind, noise, humidity, particulate andlor air quality sensor; and a power supply.30. The ventilator as claimed in claim 29 further comprising a building energy management system coupled electronically with the master room controller.31. The ventilator as claimed in claim 30 further comprising a time clock.32. The ventilator as claimed in any one of claims 29 to 31 further comprising a signal conditioning unit.33. An array of adjustable building ventilators for mounting at a roof of a building, each ventilator of the array comprising: a plurality of vent blades mountable at an external facing region of a frame defining a duct through the roof of a building, the duct configured to convey air between an exterior and an interior of the building; wherein the blades are stacked on top of one another to form a set of louvres; a blade mount configured to allow each one of the blades to move in an upward and downward direction relative to neighbouring blades and the frame; and wherein the blades are moveable in an upward and downward direction between an extended configuration in which the blades are spaced apart from one another and a collapsed configuration in which the blades are brought together to reduce the space between the blades in the vertical direction.34. The array of ventilators as claimed in claim 33 further comprising at least one actuator connected to the blade mount and/or at least one of the blades and operative to move the blades in the upward and down directions.35. A building comprising a ventilator as claimed in any one claims 1 to 32.36. A building comprising an array of ventilators as claimed in claims 33 or 34.Amendments to the claims have been filed as follows Claims: 1. A building roof adjustable ventilator for mounting at a roof of a building, the ventilator comprising: a plurality of vent blades mountable at an external facing region of a frame defining a duct through the roof of the building, the duct configured to convey air between an exterior and an interior of the building; wherein the blades are stacked on top of one another to form a stack of louvres; a blade mount configured to allow each one of the blades to move in an upward and downward direction relative to neighbouring blades and the frame; and an actuator connected to the mount and/or at least one of the blades and operative to move each one of the blades in the upward and downward direction between an extended configuration in which the blades are spaced apart from one another in a vertical direction and a collapsed configuration in which the blades are brought together to reduce r ........ 15 the space between the blades in the vertical direction.2. The ventilator as claimed in claim 1 wherein each blade comprises: CO a leading edge that is external facing relative to the duct and a trailing edge that is C\I internal facing relative to the duct; and a flange extending from the leading edge and orientated transverse to a plane of the blade; and wherein a length of each blade in a horizontal plane increases from a lowest to a highest blade such that when the blades are in the collapsed configuration the flanges of neighbouring blades overlap in the vertical direction.3. The ventilator as claimed in claim 2 further comprising at least one elongate guide rod, the guide rod allowing movement of the blades in the vertical direction relative to neighbouring blades and the frame.4. The ventilator as claimed in claim 3 wherein each blade is mounted at a guide rod via its trailing edge.5. The ventilator as claimed in claim 3 or 4 wherein each blade is mounted at the guide rod via a bushing such that each blade is capable of sliding along a length of the guide rod.6, The ventilator as claimed in claim 5 further comprising a sealing gasket mounted at a region of the bushing.7. The ventilator as claimed in claim 6 wherein each sealing gasket comprises a resiliently biased barb upwardly extending and capable for folding downwardly when contacted against an upper neighbouring sealing gasket when the blades are collapsed together.8. The ventilator as claimed in claim 7 wherein each sealing gasket comprises a nibber material. r -159. The ventilator as claimed in claim 8 wherein an upward facing surface of each sealing gasket is inclined relative to a horizontal plane. C")(sJ 10. The ventilator as claimed in any preceding claim further comprising a collapsible mesh extending from a lowest blade to a highest blade of the stack of louvres in the vertical direction and capable of collapsing when the stack of louvres are brought together to reduce the space between the blades in the vertical direction.
11. The ventilator as claimed in claim 10 wherein the mesh comprises a deformable material.
12. The ventilator as claimed in claim 10 wherein the mesh comprises a corrugated structure.
13. The ventilator as claimed in claim 10 wherein the mesh is positioned at an internal region of the stack of louvres.
14. The ventilator as claimed in any preceding claim further comprising at least one blade linkage connecting each blade in the vertical direction such that when an upper blade of the stack of louvres is actuated to move in an upward direction, a neighbouring lower blade of the stack of louvres is actuated to also move in the upward direction via the blade linkage.
15. The ventilator as claimed in claim 14 wherein the blade linkage comprises a plurality of cables connected to each blade.
16. The ventilator as claimed in preceding claim further comprising a head frame slideably mounted at the blade mount and connected to the actuator such that the actuator is operative to move the head frame in an upward and downward direction relative to the frame. r 15
17. The ventilator as claimed in any preceding claim wherein the actuator comprises a v-piston arrangement operative by pneumatic, hydraulic, electronic or electromagnetic actuation. C")C\I
18. The ventilator as claimed in claim 17 further comprising an automated control module operative to provide automated control of the piston arrangement.
19. The ventilator as claimed in claim 17 comprising a manual control configured to allow a user to control manually actuation of the piston arrangement.
20. The ventilator as claimed in any preceding claim further comprising an input and/or extraction fan positioned within the ventilator.
21. The ventilator as claimed in claim 20 further comprising a photovoltaic cell to provide power to the fan.
22. The ventilator as claimed in any preceding claim further comprising a roof enclosure extending above an uppermost blade of the stack of louvres in the vertical direction to define a cavity above the stack of louvres.
23. The ventilator as claimed in any preceding claim when dependent on claim 6 further comprising a heating assembly to provide heating of the bushings and/or blade mount.
24. The ventilator as claimed in claim 23 further comprising a reservoir for a heating fluid to circulate in contact with the bushings and/or blade mount.
25. The ventilator as claimed in claim 24 wherein the reservoir is defined, in part, by each sealing gasket, the ventilator further comprising a heating element to heat the fluid within the reservoir. r i-1526. The ventilator as claimed in any one of claims 23 to 25 further comprising a heating element connected to the blade mount. C")(1 27. The ventilator as claimed in any preceding claim further comprising at least one collapsible partition extending through an internal region of the stack of louvres in the vertical direction, the partition configured to collapse when the stack of louvres is moved to the collapsed configured to partition an internal space of the ventilator to create separate airflow channels in the vertical direction through the ventilator.28. The ventilator as claimed in claim 27 wherein the collapsible partition comprises: an outer mesh frame defining an elongate duct, the mesh frame allowing the through flow of air; and at least one internal wall extending within said elongate duct to partition the internal space of said elongate duct along its length.29. The ventilator as claimed in any preceding claim further comprising: a master room controller; at least one external building sensor being at least one of a temperature, rain/snow, wind, noise, humidity, particulate and/or air quality sensor; and a power supply.30. The ventilator as claimed in claim 29 further comprising a building energy management system coupled electronically with the master room controller.31. The ventilator as claimed in claim 30 further comprising a time clock.32. The ventilator as claimed in any one of claims 29 to 31 further comprising a signal conditioning unit.33. An array of building roof adjustable ventilators for mounting at a roof of a building, each ventilator of the array comprising: r a plurality of vent blades mountable at an external facing region of a frame defining a duct through the roof of the building, the duct configured to convey air between an exterior and an interior of the building; wherein the blades are stacked on top of one another to form a set of louvres; (sJ a blade mount configured to allow each one of the blades to move in an upward and downward direction relative to neighbouring blades and the frame; and wherein the blades are moveable in an upward and downward direction between an extended configuration in which the blades are spaced apart from one another in a vertical direction and a collapsed configuration in which the blades are brought together to reduce the space between the blades in the vertical direction.34. The array of ventilators as claimed in claim 33 further comprising at least one actuator connected to the blade mount and/or at least one of the blades and operative to move the blades in the upward and downward directions.35. A building comprising a ventilator as claimed in any one claims I to 32.36. A building comprising an array of ventilators as claimed in claims 33 or 34.