System and method for ventilating a defined space

Abstract

The present invention relates to a system ( 100 ) for ventilating a defined space ( 102 ), such as for example an enclosed or at least partly enclosed basement, crawlspace or attic. The system ( 100 ) comprises a control unit ( 110 ) connected to at least one inside sensor ( 104 ), at least one outside sensor ( 106 ) and a controllable fan ( 108 ), the control unit ( 110 ) being configured to operate the controllable fan ( 102 ) if the absolute humidity (AH out ) outside of the defined space ( 102 ) is lower or equal to the absolute humidity (AH in ) within the defined space ( 102 ), and the temperature (T in ) within the defined space ( 102 ) is above a predetermined temperature when the temperature (T in ) outside of the defined space ( 102 ) is below the temperature (T in ) within the defined space ( 102 ). Advantages of the invention include energy efficient ventilation of the defined space and a high level of protecting from moisture related problems.

1 . A system for ventilating a defined space, comprising:
 at least one inside sensor configured to measure temperature and relative humidity within the defined space;   at least one outside sensor configured to measure temperature and relative humidity outside of the defined space;   a controllable fan adapted to ventilate the defined space; and   a control unit connected to the at least one inside sensor, the at least one outside sensor ( 106 ) and the controllable fan, the control unit being configured to determine absolute humidity within the defined space and absolute humidity outside of the defined space, wherein the control unit is further configured to operate the controllable fan if:   the absolute humidity outside of the defined space is lower or equal to the absolute humidity within the defined space, and   the temperature within the defined space is above a predetermined temperature threshold when the temperature outside of the defined space is below the temperature within the defined space.   
     
     
         2 . The system of  claim 1 , wherein the control unit is further configured to only operate the controllable fan if also the temperature outside the defined space is above a predetermined temperature threshold when the temperature outside of the defined space is below the temperature within the defined space. 
     
     
         3 . The system of  claim 1 , wherein the predetermined temperature threshold is within the range of 3-10° C., preferably 4-8° C. and most preferably 5-6° C. 
     
     
         4 . The system of  claim 1 , wherein the defined space is at least one of a basement, a crawlspace, a boat, an attic, a storage room, a caravan, a trailer, a cabin, a container. 
     
     
         5 . The system of  claim 1 , wherein the system comprises at least two outside sensors arranged on opposite sides of the defined space. 
     
     
         6 . The system of  claim 1 , wherein the system further comprises at least one controllable valve connected to the control unit, and the control unit is further configured to close the at least one controllable valve if the absolute humidity outside of the defined space is higher than the absolute humidity within the defined space. 
     
     
         7 . The system of  claim 6 , wherein the system further comprises a dehumidifier connected to and controllable by the control unit, the control unit further being configured to close the at least one valve and operate the dehumidifier if the relative humidity within the defined space is above a predefined humidity threshold. 
     
     
         8 . The system of  claim 7 , wherein the predetermined humidity threshold is within the range of 50-90%, preferably 60-80% and most preferably 65-75%. 
     
     
         9 . The system of  claim 1 , wherein the system further comprises an operator accessible logger connected to the control unit and configured to log data from the inside and/or outside sensor(s). 
     
     
         10 . A method for ventilating a defined space, the method comprising the steps of:
 acquiring temperature and relative humidity within the defined space using at least one inside sensor;   acquiring temperature and relative humidity outside of the defined space using at least one outside sensor;   determining absolute humidity within the defined space;   determining absolute humidity outside of the defined space; and   operating a controllable fan if:   the absolute humidity outside of the defined space is lower or equal to the absolute humidity within the defined space, and   the temperature within the defined space is above a predetermined temperature threshold when the temperature outside of the defined space is below the temperature within the defined space.   
     
     
         11 . The method of  claim 10 , wherein the controllable fan is operable only if also the temperature outside the defined space is above a predetermined temperature threshold when the temperature outside of the defined space is below the temperature within the defined space. 
     
     
         12 . The method of  claim 10 , further comprising the step of logging data from the inside and/or outside sensor(s). 
     
     
         13 . The system of  claim 1 , wherein the predetermined temperature threshold is within the range of 4-8° C. 
     
     
         14 . The system of  claim 1 , wherein the predetermined temperature threshold is within the range of 5-6° C. 
     
     
         15 . The system of  claim 7 , wherein the predetermined humidity threshold is within the range of 60-80%. 
     
     
         16 . The system of  claim 7 , wherein the predetermined humidity threshold is within the range of 65-75%.