XPost: alt.tv.hometime, alt.building.construction, alt.tv.home-imprvment 
 XPost: alt.home.automation 
 From: philscott@philscott.net 
  
 "Some Guy"  wrote in message 
 news:42BEF3E8.85790470@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. 
  
  
  no suprise...sure water cooling works...did you say that was 
 on an 85F day?     so you cooled the roof to within 15 
 degrees.    Venting with enough air would have taken the attic 
 temp closer to the air temp that was used for venting.  as a 
 wild guess your load vs the cfm....90 deg F. maybe 98 or even 
 warmer...depends on how big fan is and type of roof 
 construction. 
  
 again. its the temp inside the first 1/2 inch of attic 
 insulation thats most relevant. 
  
 You have 'what works' confused with whats practical. 
  
 Phil Scott 
  
  
 > 
 > 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)