GB2316188A - Controlling ventilation apparatus by humidity measurement - Google Patents
Controlling ventilation apparatus by humidity measurement Download PDFInfo
- Publication number
- GB2316188A GB2316188A GB9627135A GB9627135A GB2316188A GB 2316188 A GB2316188 A GB 2316188A GB 9627135 A GB9627135 A GB 9627135A GB 9627135 A GB9627135 A GB 9627135A GB 2316188 A GB2316188 A GB 2316188A
- Authority
- GB
- United Kingdom
- Prior art keywords
- humidity
- ventilation
- period
- readings
- microprocessor
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D22/00—Control of humidity
- G05D22/02—Control of humidity characterised by the use of electric means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
- F24F11/63—Electronic processing
- F24F11/65—Electronic processing for selecting an operating mode
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F2110/00—Control inputs relating to air properties
- F24F2110/20—Humidity
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Fuzzy Systems (AREA)
- Mathematical Physics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Ventilation (AREA)
- Air Conditioning Control Device (AREA)
Abstract
Apparatus for ventilating a building or room space switches on a ventilator in response to humidity measurement by comparing the current measured value of humidity with the average of the humidity readings over a period of time. A second humidity reading is made after the ventilation has been operating for a period of time, and the time for which the ventilation is switched on is determined from the difference between the second reading and the average reading. As described, the ventilation apparatus 1 is controlled by microprocessor 6 which receives inputs from humidity sensor 2 and temperature sensor 7.
Description
VENTILATION CONTROLLING APPARATUS
This invention relates to apparatus for ventilating a building or a room space and
to a humidity sensitive control device responding to Relative, Absolute or
Specific humidity for such apparatus. The ventilating apparatus can be a
extractor fan, positive pressure fan, air heat recovery using simultaneous intake
and extract of air or any device able to dry and or change the moisture content
of the air and require control based on the water content in the air. The
ventilation apparatus to displace the existing air and thereby effect the water
content by dilution of the air with the make up air.
It is the object of this invention to provide quantitative control of a ventilation
system based on assessment of the water content of air.
It is known to provide buildings, or rooms within buildings, with ventilation
apparatus including a humidity-sensitive control device, arranged to activate the
ventilation apparatus. Examples of mechanism available to determine this
activation are as follows; a) only when the interior humidity level is above a predetermined threshold
(conventional humidistat) b) detection of rate of change of increase in humidity (GB 2 133 588) c) proportional extract ventilation rate in response to humidity level above a
predetermined threshold (conventional variable speed fan with humidity
controller) d) Detection of humidity with temperature change compensation (conventional
humidistat technology in general use since 1983 - known as night time set back).
e) Sampled, averaged and stored humidity level establishing a predetermined
humidity threshold above this level GB 9616699.6
All the above examples use the Relative Humidity (RH) scale to determine a level
when to operate ventilation equipment. This is fraught with problems arising
from the RH scale itself which gives a value of water content (usually as a %) in
relation to temperature, this giving an indicator of air saturation by moisture
content. By way of example cooking and tumble dryers produce copious
amounts of water vapour, however a local %RH controller would only register
a slight increase in %RH or in some cases a reduction of %RH, this is due to the
simultaneous increase in temperature causing the air to hold more moisture and
therefore not give cause to a rise in %RH. Other factors include changes in
weather conditions causing fluctuations of ambient humidity and temperature,
and geographic locations such as near the sea, lakes, rivers and within valleys.
Controllers that monitor only current or memorise one off readings of Relative
Humidity such as GB 2 133 588 and GB 2 298 057 produce a nomadic
response, as at the moment of sensing a variety of influences effect these one off
readings; Weather changes including pressure, temperature, and moisture
content of air. Gradual changes of humidity and temperature. Fast short peaks
of moisture (such as a kettle boiling below a sensor) or slow moisture
production (such as clothes drying).
Controllers relying on the %RH scale require large tolerances in the setting of the
control levels due to the effects of changing temperature and pressure. As the
existing controllers are not relying on the water content increase of the air alone,
erratic control results. The control is not quantitative in relation to the water
production to which it is meant to control. The results to the user are irritating
as they either have equipment running too long too short or not at all, and
apparently not duplicating previous control times.
Absolute and specific Humidity levels provide for true assessable levels of the
moisture content of air, a rise in moisture level would always cause a rise in
absolute humidity and at a constant pressure, a rise of specific humidity.
A direct relation between Relative Humidity and Absolute Humidity can be
achieved by not including the temperature aspect (measurement) when the
sensor detects humidity or by way of the example compensating a RH sensor
with a temperature sensor and calculating the Absolute Humidity in grams of
water per meter cubed of air.
A further more accurate humidity assessment is achieved by using an air pressure
sensor in conjunction with the Absolute Humidity level providing a Specific
Humidity reading of grams of water per Kilogram of air.
This invention is characterised by a control device which has a variable reference
point based on sampled humidity levels and to a means of determining a reliable
humidity reading to achieve the length of period a ventilation device should
operate following activation. The sampled humidity levels being converted and
stored as any of the following; 1. % Relative Humidity 2. Absolute Humidity 3. Specific Humidity
The processor operates the ventilator by relay when certain humidity conditions
are met. The processor software calculates the humidity average value over a
given period providing a base reference. When the humidity increases above a
set threshold level above the base reference, the ventilation apparatus is
activated. A second set of humidity readings occurs after activation of the
ventilation apparatus. The humidity difference from the base reference and the
average of the second set of humidity reading provides the basis to calculate the
total running time of the ventilation apparatus. Subject to the humidity not
returning to the reference base level in which case the ventilator will be
deactivated.
Ventilation apparatus in accordance with the present invention is characterised by
a control device which has a variable reference point based on a set of sampled
humidity levels such an apparatus is more sensitive to humidity control
requirements and is more universally adaptable than apparatus relying solely on
a humidity level or rate of change of humidity level. In its preferred form the
apparatus can successfully discriminate from household humidity production
and that from weather change, and temperature change, It is able to detect
humidity produced slowly, i.e. that caused by clothes drying and humidity
produced in a large room, that is humidity levels just above ambient humidity.
The ambient humidity(Reference base) being defined by the controller from an
average of humidity samples taken by the controller over a period of time.
A second set of humidity readings(Relevant Humidity) are taken the average of
which are compared with the reference base. The difference in these readings
provides a basis to calculate the ventilator running times.
This Relevant Humidity value provides a level obtained when the ventilation
system (whatever its efficiency) is operating and when the humidity source
status is obtained, as such a humidity level taken at this time has a direct
relationship between the efficiency of the extraction source and the humidity
producing source (although this source can be variable). Determination of a
ventilator control period at the time of this second humidity reading provides a
basis for the anticipated control period. The relevant humidity value is obtained
shortly after operation, typically three minutes, this is sufficiently short a period
to discount ambient changes due to weather and geographic position. At this
time the vapour diffusion levels to cooler parts of the building are being
contained as much as possible by the ventilator under control.
In its preferred form the apparatus can successfully determine control periods and
thereby optimise the ventilation unit for efficiency and condensation control.
A Ventilation control apparatus including a control unit and ventilator in
accordance with the present invention, will now be described, by way of
example, with reference to the accompanying drawings, in which:
Figure 1 shows the system schematically; and
Figure 2 shows the system schematically for specific humidity; and
Figure 3 illustration relationship between %Relative Humidity - Absolute
Humidity and Temperature
Figure 4 Absolute Humidity - Temperature threshold tables for controller
Figure 5 Absolute Humidity level vs. Running times of ventilator
The ventilation system comprises an extractor fan 1 mounted in an external wall
or window of a conventional domestic dwelling, close to the moisture sources
in either the kitchen or bathroom. The extractor fan 1 is electrically powered
and connected by wire to the output relay 9 of the control unit 11. The control
unit 11 includes a microprocessor 6, probe sense amplifier 3, probe log
converter 4, analogue to digital converter 5, Relay 9 and LED status indicator
8, and is connected to thermister 7 and humidity sensor 2.
The sensed Humidity is continually supplied to the microprocessor via probe
sense amplifier 3, the probe log converter 4 and A to D converter 5. The
microprocessor programming converts the Humidity readings to Absolute
humidity with as required the temperature input from the thermister, readings
from the humidity sensor are averaged over 30 seconds this average value is
then supplied for memory storage, these readings are then stored for two hours
the average over this two hour period is used as the base reference. The base
reference is updated every two hours with the average of the absolute humidity
reading taken over the preceding two hour period. During activation periods of
the extractor fan humidity readings for the base reference are suspended, this is
to avoid spurious ambient readings during the desiccation period.
A threshold level of absolute humidity above the base reference is chosen
sufficiently high to avoid ambient humidity variations that could occur over a
two hour period but low enough to activate the ventilator with moisture
production. The Absolute Humidity threshold level is altered at different
temperatures, as shown in Figure 4.
Once the Absolute humidity has gone above the threshold the ventilator is
activated, after 3 minutes of activation the Absolute Humidity level is again
compared with the base reference level, the level of Absolute humidity above
this base will determine the total running time as figure 5. Note the controller
can be set to operate for double the period expressed in figure 5 when used with
less efficient ventilation systems such as air heat recovery and positive air
pressure systems. this is achieved by cutting link 12 which adjusts the
microprocessor program.
If at any time during ventilator activation the absolute humidity level falls to the
same or less than the base reference level then the activation period is
suspended.
If at the end of a timed activation period the Absolute Humidity is above the
Threshold level then a further activation period is activated as Figure 5
Specific Humidity Controller as Figure 2, Operation as Absolute Humidity
Controller with Pressure input compensating for atmospheric changes of
pressure.
Relative Humidity as Figure 1, Operation as Absolute Humidity Controller
without thermister input. With the following control; The %RH is stored over
the two hour period and used as the base reference (being updated every two
hours). The base reference is compared with humidity samples taken after 3
minutes of ventilator operation (this sample taken over 30 seconds and then
averaged). The difference %RH between the base average and the sample after
3 minutes is used to calculate total running time.
For general extraction this would equate to 2 X % Relative Humidity(%RH)
difference = number of minutes the extractor operates.
For ventilation units such as positive pressure or air heat recovery the minimum
operation periods would be double, i.e. 4 X % Relative Humidity difference =
number of minutes of ventilation.
KEY FOR FIGURE 1
A control for ventilation apparatus 1, humidity sensor 2 the output of which are amplified by probe sense amplifier 3 this output is supplied to probe log converter 4 which is then supplied to the Analogue to Digital converter 5 this digital information then supplied to the microprocessor 6. Thermistor 7 connected to microprocessor 6.
The processor operates the ventilator by relay 9 when certain absolute humidity condition are met. The processor calculates the absolute humidity the average value over a given period is used as a reference, when the absolute value of humidity increases above a given threshold above this reference ventilation apparatus 1 is activated. A further humidity reading after a given time is taken while the ventilation apparatus 1 has been activated, the humidity difference from the reference and this further reading provides the basis to calculate the actual total running time of the ventilation apparatus 1.
KEY FOR FIGURE 2
A control for ventilation apparatus 1 humidity sensor 2 the output of which are amplified by probe sense amplifier 3 this output is supplied to probe log converter 4 which is then supplied to the Analogue to Digital converter 5 this digital information then supplied to the microprocessor 6. Thermistor 7 and pressure transducer 10 are connected to microprocessor 6.
The processor operates the ventilator by relay 9 when certain specific humidity condition are met. The processor calculates the specific humidity the average value over a given period is used as a reference, when the absolute value of humidity increases above a given threshold above this reference ventilation apparatus 1 is activated. A further humidity reading after a given time is taken while the ventilation apparatus 1 has been activated, the humidity difference from the reference and this further reading provides the basis to calculate the actual total running time of the ventilation apparatus 1.
Claims (12)
1. A ventilation controlling apparatus comprising a humidity sensor operable
to produce an electrical signal the level of which is determined by the humidity
of air at the sensor, and the microprocessor electrical circuitry coupled to the
sensor, wherein said microprocessor means stores the humidity, the average of
the humidity reading is calculated over a period of time the value of which acts
as a reference base of Humidity. When a predetermined threshold of humidity
exceeds the reference base of humidity said microprocessor means is arranged
to provide said ventilation output control signal.
2. A device according to claim 1, wherein a second humidity reading is taken
after a significant period following activation of the ventilation equipment. This
second humidity reading is compared by the microprocessor with the reference
base of humidity (determined within claim 1), the difference in humidity levels
provides the calculation bases for the time period of the ventilation output
control signal.
3. As claim 1 wherein said microprocessor means stores and averages the
humidity in small sampling periods, the average of the humidity readings in
these small sampling periods of time are compiled over a longer period of time
the average of which acts as a reference base of Humidity. When a
predetermined threshold of current small sampling period of humidity exceeds
the reference base of humidity said microprocessor means is arranged to
provide said ventilation output control signal.
4. A device according to claim 1, A second reading of humidity in a small
sampling period is taken after a significant period following activation of the
ventilation equipment. This second humidity reading is compared by the
microprocessor with the reference base of humidity (determined within claim 1),
the difference in humidity level provides the calculation basis for the time period
of the ventilation output control signal.
5. A ventilation system according to any one of the preceding claims, wherein
said microprocessor means is arranged to detect store and calculate based on
the Absolute Humidity, humidity readings adjusted by temperature sensor
readings to match as required the characteristics of the humidity sensor used.
6. A ventilation system according to any one of the preceding claims, wherein
said microprocessor means is arranged to detect store and calculate based on
the % Relative Humidity, humidity readings adjusted by temperature sensor
readings to match as required the characteristics of the humidity sensor used.
7. A ventilation system according to any one of the preceding claims, wherein
said microprocessor means is arranged to detect store and calculate based on
the Specific Humidity, humidity readings adjusted by temperature sensor
readings to match as required the characteristics of the humidity sensor used,
humidity readings also adjusted by air pressure sensor.
8. A ventilation system according to any one of the preceding claims, wherein
the humidity reference is compiled from any stored historical humidity data.
9. A device according to any one of the preceding claims, wherein the electrical
circuitry includes a storage stage compiled from any number of inputs to
achieve reference based on historical storage data, and then the value of
humidity in any form obtained from the historical storage to act as a reference
signal that is then to be compared with sensed humidity input.
10. A device according to any one of the preceding claims, wherein the output
signal is dependent on both the averaged stored reference value of Relative
Humidity and the sensed value of Relative Humidity.
11. A ventilation controlling apparatus according to any one of the preceding
claims, wherein a second humidity reading is taken after a significant period
following activation of the ventilation equipment. This second humidity reading
used to control said ventilation equipment.
12. A ventilation controlling apparatus for controlling ventilation
apparatus, the ventilation controlling apparatus being constructed and
arranged substantially as herein described and shown in the drawings.
12. A ventilation controlling apparatus according to any one of the preceding
claims, wherein the control output may be supplied to any equipment able to
alter moisture content.
13. A device according to any one of the preceding claims, wherein the
sampled humidity level is compared to Relative humidity level during or at the
end of the rate of change of humidity that led to a control period, the resultant
humidity difference representing the basis which determines the total control
period.
14. A device according to any one of the preceding claims, wherein the
sampled humidity level is compared to Relative humidity level at the start of the
rate of change of humidity and temperature either simultaneously or
interactively combined that led to a control period the resultant humidity
difference representing the basis which determines the total control period.
15. Apparatus for controlling ventilation in a building or room space, including
a control device according to any preceding claims.
16. Apparatus to control temperature using a temperature input instead of
humidity in accordance with any one of the preceding claims.
17. A control device for controlling ventilation apparatus, the device being
constructed and arranged substantially as herein described and shown in the
drawings.
18. Any novel features or combination of features as hereinbefore described.
Amendments to the claims have been filed as follows
CLAIMS 1. A ventilation controlling apparatus comprising a humidity sensor
operable to produce an electrical signal the level of which is determined
by the humidity of air at the sensor, and microprocessor electrical
circuitry coupled to the sensor, wherein said microprocessor stores the
humidity, the average of the humidity reading is calculated over a period
of time the value of which average acts as a reference base of humidity,
then when the measured humidity exceeds the reference base of humidity
by a predetermined amount said microprocessor means is arranged to
provide a ventilation output control signal.
2. A ventilation controlling apparatus according to claim 1, wherein a
second humidity reading is taken after a significant period following
provision of said ventilation output control signal the second humidity
reading is compared by the microprocessor with the reference base of
humidity, and the difference in humidity levels provides the calculation
basis for the time period of the ventilation output control signal.
3. A ventilation controlling apparatus according to claim 1, wherein said
microprocessor stores and averages the humidity in small sampling
periods, the average of the humidity readings in these small sampling
periods of time are compiled over a longer period of time the average of
which acts as a reference base of humidity, and when the average value
of humidity in the current small sampling period exceeds the reference
base of humidity by a predetermined threshold said microprocessor is
arranged to provide said ventilation output control signal.
4. A ventilation controlling apparatus according to claim 1, wherein a
second reading of humidity in a small sampling period is taken after a
significant period following provision of the ventilation output control
signal, this second humidity reading is compared by the microprocessor
with the reference base of humidity and the difference in humidity level
provides the calculation basis for the time period of the ventilation
output control signal.
5. A ventilation controlling apparatus according to any one of the
preceding claims, wherein said microprocessor means is arranged to
detect store and calculate based on the Absolute Humidity, humidity
readings adjusted by temperature sensor readings to match as required
the characteristics of the humidity sensor used.
6. A ventilation controlling apparatus according to any one of the
preceding claims, wherein said microprocessor means is arranged to
detect store and calculate based on the % Relative Humidity, humidity
readings adjusted by temperature sensor readings to match as required
the characteristics of the humidity sensor used.
7. A ventilation controlling apparatus according to any one of the
preceding claims, wherein said microprocessor means is arranged to
detect store and calculate based on the Specific Humidity, humidity
readings adjusted by temperature sensor readings to match as required
the characteristics of the humidity sensor used, humidity readings also
adjusted by air pressure sensor.
8. A ventilation controlling apparatus according to any one of the
preceding claims, wherein the humidity reference is compiled from any
stored historical humidity data.
9. A ventilation controlling apparatus according to any one of the
preceding claims, wherein the output signal is dependent on both the
averaged stored reference value of Relative Humidity and the sensed
value of Relative Humidity.
10. A ventilation controlling apparatus according to any one of the
preceding claims, wherein the control output may be supplied to any
equipment able to alter moisture content.
11. Apparatus for controlling ventilation in a building or room space,
including a ventilation controlling apparatus according to any preceding
claim.
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP97935687A EP0917677B1 (en) | 1996-08-09 | 1997-08-08 | Ventilation controlling apparatus |
CA002262657A CA2262657C (en) | 1996-08-09 | 1997-08-08 | Ventilation controlling apparatus |
JP10509502A JP2001500291A (en) | 1996-08-09 | 1997-08-08 | Ventilation control device |
AT97935687T ATE229664T1 (en) | 1996-08-09 | 1997-08-08 | REGULATOR FOR A VENTILATION SYSTEM |
PCT/GB1997/002155 WO1998007083A1 (en) | 1996-08-09 | 1997-08-08 | Ventilation controlling apparatus |
DE69717821T DE69717821D1 (en) | 1996-08-09 | 1997-08-08 | CONTROLLERS FOR A VENTILATION SYSTEM |
US09/242,085 US6230980B1 (en) | 1996-08-09 | 1997-08-08 | Ventilation controlling apparatus |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB9616699.6A GB9616699D0 (en) | 1996-08-09 | 1996-08-09 | Ventilation controlling apparatus |
GBGB9623525.4A GB9623525D0 (en) | 1996-08-09 | 1996-11-11 | Optimisation for ventilation controlling apparatus |
Publications (3)
Publication Number | Publication Date |
---|---|
GB9627135D0 GB9627135D0 (en) | 1997-02-19 |
GB2316188A true GB2316188A (en) | 1998-02-18 |
GB2316188B GB2316188B (en) | 1998-07-29 |
Family
ID=26309840
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9627135A Expired - Fee Related GB2316188B (en) | 1996-08-09 | 1996-12-31 | Ventilation controlling apparatus |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2316188B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2400457A (en) * | 2003-04-05 | 2004-10-13 | Ebac Ltd | Dehumidifier control system |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2209070A (en) * | 1987-08-25 | 1989-04-26 | System Controls | Humidity and ventilation control |
US4953784A (en) * | 1986-12-24 | 1990-09-04 | Kabushiki Kaisha Toshiba | Ventilator drive system |
US5232152A (en) * | 1991-10-30 | 1993-08-03 | Tsang Richard W B | Range hood fan with atmospheric humidity sensor |
-
1996
- 1996-12-31 GB GB9627135A patent/GB2316188B/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4953784A (en) * | 1986-12-24 | 1990-09-04 | Kabushiki Kaisha Toshiba | Ventilator drive system |
GB2209070A (en) * | 1987-08-25 | 1989-04-26 | System Controls | Humidity and ventilation control |
US5232152A (en) * | 1991-10-30 | 1993-08-03 | Tsang Richard W B | Range hood fan with atmospheric humidity sensor |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2400457A (en) * | 2003-04-05 | 2004-10-13 | Ebac Ltd | Dehumidifier control system |
GB2400457B (en) * | 2003-04-05 | 2006-10-11 | Ebac Ltd | Dehumidifier control system |
Also Published As
Publication number | Publication date |
---|---|
GB9627135D0 (en) | 1997-02-19 |
GB2316188B (en) | 1998-07-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0917677B1 (en) | Ventilation controlling apparatus | |
US6223543B1 (en) | Effective temperature controller and method of effective temperature control | |
US6186407B1 (en) | Humidity control based on an estimation using heating plant cycle, of inside window surface temperature | |
US8352082B2 (en) | Methods and apparatuses for displaying energy savings from an HVAC system | |
US6776817B2 (en) | Airflow sensor, system and method for detecting airflow within an air handling system | |
US4361273A (en) | Electronic humidity control | |
KR890006098A (en) | Temperature sensing fault detection device using heater energy counter | |
US7075041B2 (en) | Method for controlling a cooking process in a cooking appliance and cooking appliance | |
WO2011088270A4 (en) | Ventilation control system and method | |
EP0672374A1 (en) | Protection and control of continuous boiling water units | |
US11739948B2 (en) | Automatic oven with humidity sensor | |
KR20180121810A (en) | Closed control dehumidification method and apparatus for preventing condensation | |
US4793553A (en) | Infrared thermostat control | |
JP2000097480A5 (en) | ||
GB2316188A (en) | Controlling ventilation apparatus by humidity measurement | |
US4161660A (en) | Apparatus for producing a time-proportioned control signal electronically | |
RU2003114860A (en) | BOLOMETRIC HYGROMETER, PLATE OR FURNACE WITH ITS USE AND METHOD FOR REGULATING A PLATE OR FURNACE | |
JP2928151B2 (en) | Water vapor partial pressure conversion type humidity controller | |
GB2210966A (en) | Ventilating fan control arrangement | |
KR20210100995A (en) | IoT-based building insulation efficiency measurement system and method | |
KR910008824B1 (en) | Out-door ambient temperature determination | |
JP2914186B2 (en) | Control device for electrical equipment | |
EP0945772A3 (en) | Device for the high-precision control of a physical quantity such as the temperature or humidity in a household electrical appliance | |
López et al. | Temperature and Humidity Laboratory Remote Controller | |
GB2048519A (en) | Control apparatus for air drying equipment |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20061231 |
|
S28 | Restoration of ceased patents (sect. 28/pat. act 1977) |
Effective date: 20080723 |
|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20101231 |