Damper control in space heating and cooling

Abstract

An amount of time that air has been delivered from an air handler to a space is tracked, and based on the tracked amount of time, at least one turn-on time or one turn-off time of the delivery of air from the air handler to the space is controlled. Other features relate, among other things, to controlling a replacement air vent, and to user interfaces.

1 - 35 . (canceled)  
   
   
       36 . A method comprising 
 sensing flow of replacement air through a vent to an air handler,    opening and closing the vent to regulate delivery of replacement air to the air handler to achieve an intended rate of flow, and    based on the sensed flow, determining a clogging state of the filter.    
   
   
       37 . The method of  claim 36  in which the clogging state comprises the filter being clogged.  
   
   
       38 . The method of  claim 36  in which the clogging state comprises the filter being new.  
   
   
       39 . The method of  claim 36  in which sensing flow of replacement air comprises sensing a change in the flow over time.  
   
   
       40 . The method of  claim 36  in which determining the clogging state includes comparing the sensed flow to a threshold value of flow.  
   
   
       41 . The method of  claim 40  in which the threshold value of flow is set empirically.  
   
   
       42 . The method of  claim 41  in which the threshold value of flow is set based on the history of the sensed flow.  
   
   
       43 . The method of  claim 36  in which sensing flow of replacement air is done by measuring a rate of rotation of a fan drive by the flow, or by measuring pressure of the air, or by measuring a velocity of the air.  
   
   
       44 . The method of  claim 36  in which the vent comprises a replacement air vent or a return air duct.  
   
   
       45 . A medium bearing instructions to cause a machine to 
 sense flow of replacement air through a vent to an air handler,    open and close the vent to regulate delivery of replacement air to the air handler to achieve an intended rate of flow, and    based on the sensed flow, determine a clogging state of the filter.    
   
   
       46 . Apparatus comprising 
 a controller to (a) sense flow of replacement air through a vent to an air handler, (b) open and close the vent to regulate delivery of replacement air to the air handler to achieve an intended rate of flow, and (c) based on the sensed flow, determine a clogging state of the filter.    
   
   
       47 - 81 . (canceled)