XPost: alt.home.repair   
   From: bashley101@gmail.com   
      
   On 1/27/23 7:00 PM, Xeno wrote:   
   > On 13/1/2023 11:04 am, micky wrote:   
   >>   
   >> Doesn't this make their legs hot?   
   >>   
   >>  From time immemorial and certainly in 1950, a car heater was turned on   
   >> and off and the temperature adjusted by a valve in the hose that sent   
   >> hot water to the car's heater core under the dash.   
   >>   
   >> But that meant when you turned on the hot water, it took time heating   
   >> the core before the core would radiate heat.  Even the hose leading to   
   >> the core probably cooled off the coolant somewhat.   
   >>   
   >> In the 70's? or 80's or 00's? some designers started sending hot water   
   >> to the core all the time and using an air blend door to determine if   
   >> cold/room temp air came out of the vents or if warm/hot air did.  Then   
   >> it only took 3 or 4 seconds to change the temp of the vent air.   
   >>   
   > The reason for the design change, and the elimination of the mechanical   
   > water valve, was the move to factory AC as standard, in particular -   
   > climate control. The delay you speak of is the reason that valve had to   
   > go. It was far more practical to adjust temperature with a blend door   
   > where temperature change was, for the most part, instantaneous. Couldn't   
   > achieve that if you relied on controlling water flow. Getting rid of   
   > that water valve was once of the best things that ever happened to car   
   > heaters. It was the source of many issues and without it the heater core   
   > gets a continuous flush every time the car is driven.   
      
   THANK YOU!  It seemed insane to heat/cool the car by ALWAYS using a   
   combination of hot/cold air.  I first noticed this on my mom's 1988   
   Caddy, but I figured that insanity was the norm for Cadillac.   
      
   --   
   Cheers,Bev   
      "It is a matter of regret that many low, mean suspicions   
       turn out to be well-founded."       -- Edgar Watson Howe   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)