DIY: A/C Insulation

[n00b]

Ok, I guess I should finally post.

Lets start with what the hell we are insulating. It is the low pressure line going from the firewall to the rubber hose before it hits the condensor. Its marked with a pink line at the firewall and has a pressure valved labeled "L". When run the A/C, this line should be the only one that is COLD to the touch. The smaller line that sits below it should be open to air as it is taking hot air out of the cabin and back to the condenser.

That is wrong.

The LOW pressure line is for refrigerant going to the COMPRESSOR. The HIGH pressure line is for refrigerant going to the EVAPORATOR.

Both lines should be insulated. Insulate the low pressure side to keep the refrigerant a bit cooler going into the compressor and insulate the high pressure side to prevent the refrigerant from absorbing heat from the engine bay.

Your pipe insulation may melt (I don't know how hot this line gets) if you insulate the line going from the COMPRESSOR to the CONDENSER

low > compressor > condenser > high > evaporator > repeat