BigBlue13

Yeah crystaline is about $200, I got color stable for $100

gwpfan

No short of a poor wrap job and being in a acidic environment.

One could, but that gap is going to be where your going get condensation in the the insulation as well so it'll also be a detriment.

It would only really be a factor if you were in an acidic environment and you had condensation on the line pooling up in an area and in turn that acidic condensation corroding the pipe. Very, very unlikely. I have seen pipe that the upper side the insulation got torn back/off and then it drained down to the low end behind the insulation yet in place and then pooled up and left some poor looking water marks on the pipe. Pipe though didn't seem to actually have a negative effect. Acidic environment may be like a chemical plant, areas with high sulfur in the air, etc.

A seal is better than non-sealed as where ever you have a gap in the insulation that is where water will condense. The water comes from the humidity in the surrounding air, but if the pipe insulation is a perfect seal around it, you won't get air in from the surrounding air and therefore no condensation/water on the pipe. Granted it is unlikely one will get a perfect seal, but with a good seal the amount of condensation will be so minor that the effect will be negligible.

I removed a fair amount of refrigerant pipe, some over 30 years since installed and granted that's all copper, but I can say the stuff with insulation looks and is in far better shape than the stuff without. By no means am I a metal corrosion expert but some metals work in such a manner that the corrosion will actually act as a protective layer. Granted definitely not iron.

All that said wrap the larger pipe, seal it up as good as possible and don't worry about corrosion on that.

NateC

Thanks so much to all for the advice and thoughts. I see now that insulating the line is definitely the way to go. I'll be doing it as soon as I can carve out some time.

3kushn

I'm not a metal expert either but I know for a fact that aluminum oxide is one of these cases.

GTXKen

x2

GTXKen

Thanks to the OP and others for this. Funny, I just rewrapped the line on my home compressor the other day, this should have been a no brainer. I haven't had any real issues with my F150s a/c but I have noticed its not as cold as the air in my 95 Vision

slimcubby

iTrader: (1)

So I did the mod and YES it does make the air colder.

One thing though... Our air compressor still sucks and any temp over 80* outside still makes the air kick off from ac then back on.

kevinr7290

iTrader: (1)

Did you just wrap the line in foam or did you wrap it in insulating tape too?

slimcubby

iTrader: (1)

Just the armaflex high density foam.

hddude103

While you think this is a good idea, I will have to disagree. Let me explain. Basically lets start at the compressor discharge. Hot high temperature gas is leaving and going into the top of the condenser, that large black coil in front of your radiator where that high temperature is rejected to the air with the help of the fans and moving air across this coil. As the heat is removed, the gaseous refrigerant is converted to a high pressure, lower temperature liquid. That liquid then travels through the small pipe to the expansion device which could be a TXV or an orifice tube where this HPL is sprayed (atomized) into the bottom of the evaporator, that is the part that removes heat from the cabin. In the evaporator HPL is converted to a low pressure gas as it absorbs heat causing the cooling effect. That LPG is then routed into the compressor via the large pipe. Sometimes there is a filter dryer( a large aluminum canister) installed. In the evaporator vaporized refrigerant is converted to a gas based on the amount of ambient heat across the coil. Lets say that at 70F the conversion is finished 2/3 of the way up the evap coil. As the cabin temperature comes down the conversion to a saturated gas happens later or farther up the coil which is effectively closer to the compressor. As the temp gets lower, the less heat is absorbed and the saturated refrigerant is allowed to travel closer to the compressor. Technically this is called superheat. Superheat is there to insure the evap is operating at capacity AND to make sure that all refrigerant is converted to a gas prior to entering the compressor. While the compressor is a pump, it does not like liquid refrigerant. It likes cool dry refrigerant gas. By adding insulation to the large suction pipe you have reduced the ability of the system to absorb heat from the engine compartment thereby assuring all liquid refrigerant is converted to a gas prior to entering the compressor. Bad idea, bad, bad, bad... Now, about the other side of the system, the hot high pressure liquid small pipe. That hot liquid is sprayed into the evap and absorbs heat, the lower that temperature the better as it will flash faster and absorb more heat sooner in the evaporator. Naturally there are all kinds of calculations and gauge readings that go on refrigerant systems, but you now have the basics. Insulate the small line and leave the large one alone.
Okay, I know, I know, The large pipe (suction) is insulated in my home unit. The reason for that is keep the suction line cool enough to allow low temperature gas to cool the compressor that is 25-45 feet from the evaporator. Super heat is calculated AT the evaporator, anything extra provides cooling for the compressor. Without insulation on the suction pipe at your house will the suction gas temperature rise and not cool the compressor which you will then soon replace. I do hope that I have helped someone here. The 3/8 copper liquid line at you house is not insulated where it can reject heat along its 25-45 foot run getting cooler as it gets closer to the evap.

HVAC/Refrigeration is a fascinating science