XPost: rec.arts.comics.strips   
   From: psperson@old.netcom.invalid   
      
   On Sun, 11 Jan 2026 17:23:03 -0500 (EST), kludge@panix.com (Scott   
   Dorsey) wrote:   
      
   >Thomas Koenig   wrote:   
   >>   
   >>What is R-20 and R-30?  Another kind of liberty unit? :-)   
   >   
   >Yes, it's a measure of thermal resistance.  Ironically, it appeared in the   
   >US at a time when we were actively moving toward the metric system, back   
   >in the seventies.   
   >   
   >Nobody outside of construction folks actually use it.  It was never mentioned   
   >in my thermo class.  I saw how it was calculated and it was kind of a mess.   
      
   Can I take it that actually measuring the effect with various   
   materials is not how its done?   
      
   (eg: closed room, various panels, heat/cold source on the outside,   
   thermometers on the walls/windows inside and out at the same height)   
      
   The /real/ question is: how is the thermal efficiency claimed for a   
   given oil furnace computed? Does someone just pull it out of his *ss   
   or is it something Marketing comes up with? Particularly measure   
   claiming to take into account the existing ducts.   
      
   Note that the thermal efficiency of a radiant electric heater is,   
   IIRC, 100%. I once explored this a little bit to try and figure out   
   the relative economics, but got lost in the details. Also note that   
   the current push against oil furnaces, at least up here, is based on   
   air pollution, not inefficiency or inadequacy.   
   --    
   "Here lies the Tuscan poet Aretino,   
   Who evil spoke of everyone but God,   
   Giving as his excuse, 'I never knew him.'"   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)