XPost: alt.tv.hometime, alt.building.construction, alt.tv.home-imprvment 
 XPost: alt.home.automation 
 From: Some@Guy.com 
  
 Dll wrote: 
  
 > The readout doesn't mean anything.  I'd bet you're getting 2 C 
 > max accuracy. 
  
 I'm satisfied that when I bring that particular unit (with it's 
 internal and external transducer) along with several other (different) 
 units together in the same place, and see them display a temperature 
 within 1 degree (F) of each other, that there's little chance that 
 they're all out of whack by the same amount. 
  
 > Pretty scientific test you had going there...not! 
  
 My hypothesis was that spraying water on the roof would cause a 
 decrease in attic air temperature. 
  
 My temp display before applying the spray was showing 120+ degrees 
 (f).  Within 1/2 hour of applying the spray the temp went to 100 
 degrees and leveled off to about 98 degrees after an hour. 
  
 This was scientific in that 
  
 - I had reasonable confidence in my measurement device 
 - I varied only 1 parameter during the study 
 - there were no other variables that could have affected the 
   results (like a change in outside temp, cloud cover, etc) 
  
 During the entire time the roof-mounted exhaust fan was running. 
  
 > > This is with an attic fan going. 
 > 
 > Vent fans are tried and true energy savers. 
  
 I don't know what the temp would have been without the spray and 
 without the fan running, but I agree that a vent fan (combined with 
 proper soffit ventilation) is absolutely necessary to prolong shingle 
 life and reduce the heat load to the house. 
  
 --- SoupGate-Win32 v1.05 
  * Origin: you cannot sedate... all the things you hate (1:229/2)