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Old 06-03-2008, 04:57 PM   #6 (permalink)
EcoModding Lurker
Join Date: Apr 2008
Location: Colchester, CT
Posts: 38

POS - '97 Ford Aspire
90 day: 47 mpg (US)
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Thanked 1 Time in 1 Post
this is how A/C works in your car:

- The compressor increases the pressure (and temp) of the LP vapor (R-134a).
- It then goes to the condensor (the 'radiator' in front of the coolant radiator) where heat is removed (read temp dropped) until the R-134a condenses (still at or above ambiant temp). it is still at high pressure.
- the high pressure liquid then flows to the evaporator in the cab (usually under the dash or in a compartment in engine bay passenger side against the firewall)).
- in the evaporator, the R-134a aquires the 'latent heat of vaporization' from the ambiant air in the cab. this heat transfer cools the air flowing over the evaporator. this is when the R-134a gets cold (going from liquid to gas).
- the vapor then returns to the compressor.

Insulating the condesner-to-evaporator line will do nothing, as this liquid is warm already. the time spend in the line means that if there is much of a temp difference, the amount of heat transfered will be neglible (meaning you will spend more money on insulation than you save in gas and you will not be able to measure a any temp difference in the cab).

if you want your system to be more efficient, insulate the cab and ensure your system has the proper amount (not too much or too little) R-134a in it. If you converted from R-12 to R-134a, you will need a bigger condenser to get the same cooling since R-12 is much more efficient of a refrigerant than R-134a.

so, save your time/money for an eco-mod that will work
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