This has probably been done before but... This weekend I recharged my ac system with r134. While doing this I noticed the reciver/dryer gets cold, DUH. I did know it gets cold but....
Today I was thinking about how to get the car a little cooler keep the reciver as cool as possible and prevent engine heat from soaking into the receiver.
I ended up wraping the receiver in heat reflective insulation and after a few minutes I noticed a small yet noticalbe difference in air temp. Mod worth $8? I think so.

 

Your idea also works very well on the older R-12 stuff, too. I wrapped my receiver with this foil-covered foam tape and ran pipe insulation from the receiver to the compressor. It seems to work and the High-Low pressure gages agree. The High Side doesn't have to remove the underhood heat picked up between the evaporator and compressor and the high side reads slightly lower as a result. The low side is about 1/2 PSI lower overall on a hot day. In Florida, every little bit helps!

 

I did the same. It does work nicely. The only thing to watch for is you can't run it quite as long as before, things tend to freeze up quicker. Maybe not in your hot climates but here in Idaho mine does. And it is costly. I am ok around town but on trips I need to shut it off now and then just to let things thaw a little.

 

Or when you or your ac tech recharges the system just add and extra pound or two of refrigerant...makes for a nice and cold system

 

1987fbrd, your system should not be freezing up, it sounds like you are low on refridgerant, a sure sign is freezing up the system.

 

Just a few thoughts on your insulation adventures.
That is not a reciever/dryer. It is an accumulator and it is plumbed in on the low side. (reciever/dryer's are on the high side)It pretty much does the same thing, just on the low side.

You guys are wrapping insulation around the low side components that carry low pressure GAS to the suction side of the compressor. ( Keep GAS in mind.)

When the compressor is working, it produces high pressure, high temperature GAS, which is piped into the top of the condenser core in front of your radiator.
The GAS is cooled (yes it is still hot) and comes out of the bottom of the condenser as a pressurized LIQUID.
It is then piped to an orifice tube in the evaporator inlet.
The orifice tube is a calibrated "hole". One side has high pressure liquid, the other low pressure liquid and GAS. (the orifice tube is at the bottom of the evaporator core)
When the high pressure, high temperature liquid passes through the orifice tube, the drop in pressure causes it to cool rapidly. The evaporator will partially fill with liquid, and absorb heat from air being pushed though the fins of the evaporator, this heat transfer causes the refridgerant to become a low pressure GAS that is plumbed to the accumulator. (evaporator-evaporate see the connection?)
The accumulator recieves GAS and SOME LIQUID, it acts as a storage container and moisture absorber.

Now, you guys are insulating the accumulator and low side hose to the compressor (keeping the refridgerant cold), thus lowering the pressure in the evaporator, accumulator and the low side a/c line to the compressor. This makes the pressure differential at the orifice tube greater. (lower pressure in the evaporator) Allowing the evaporator to fill up more with liquid.
This will cause more liquid to be in the accumulator than GM intended. If this liquid is allowed to go to the suction side of the compressor in a large enough quantity,,BOOM.
You just bought a compressor, because you can't compress liquid.
The accumulator is used to help EVAPORATE the liquid refridgerant before it is sent to the compressor.

Blueiroc, If you put in more than what the engineers intended, it will also cause the evaporator and accumulator to flood with liquid and..... BOOM compressor city again in the worst case, reduced cooling in the best.

1987fbird. You may want to change your pressure cycling switch.
When the compressor reduces the low side pressure to 25psi, it cuts off power to the compressor clutch. when the low side reaches 46psi the switch turns power back on. This constant cycling keeps the evaporator core discharge temperature at 33*(or thereabouts).

I'm not saying you are going to expeience catastrophic ( i've wanted to use that word all evening ) compressor explosions, but I would not alter the factory engineering. GM spent alot of money figuring this crap out.

We use insulating tape on some big truck applications, most of the time on the expansion valve.

Just my .02

 

I agree 100%. You guys are asking for the boom. Especially adding more than what it holds, thats a no no. Have any of you put a temp guage up to your vents and what was it at without the insulation? Mine was just recharged and pushes out about 40 degrees which is plenty.