[TR] Installing Heat Shield

[Dave1massey at cs.com]

In a message dated 8/23/2010 12:53:10 AM Central Daylight Time, 
tom628 at verizon.net writes: 
> Scott: I'd think you'd want the foil side up.  If you place the foil 
> against 
> the hot surface, it's just a conductor and gets as hot as the floor.. With 
> 
> the felt down against the floor, the felt acts as an insulator, and then 
> the 
> foil reflects that heat and reduces transmission into the interior of the 
> car.  JMO
> 

One would think.  The best place for the foil (which reflects infrared 
(radiant) heat) is under the floor board.  That is where they put it on the 
Spitfire.  But it needs to be waterproof and most of what you buy is not.

But since it is not waterproof, the next best thing is to located it under 
the carpet.  Laying the foil side against the floor boards puts it in 
contact with the sheetmetal but the contact is less than perfect and there will be 
gaps.  And the mode of heat conduction through the gaps will be via 
radiation and in this case the foil will reflect the heat back.

But practically speaking, I don't think it makes much difference either 
way.  The backing insulation is what is really important so get that in there 
with or without the foil, foil up or foil down.

Dave