DIY: A/C Insulation

[texkid]

Originally Posted by n00b

Ok, I guess I should finally post.

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

Ah crap! I knew I had the idea backwards. But....I am still getting colder air.

Side Note: It's a PIA to reach that high pressure line. If I can get some kind of reassurance that it'll make a significant difference, then by golly I'll grease up my body to squeeze in there if I have to.

[texkid]

Update:

Yes, I had the circulation backwards.

However, I did some more research. Insulating the high pressure side will not improve cooling. Some mechanics sites say it'll do nothing....others say it'll put more pressure on the compressor, and blah, blah, blah.

Personally, I have not seen ANY positive results on insulating the High Side. In the meantime, I am going to research for insulation that withstand higher temps.

[auxmike]

Those foams you installed are in the vicinity of the very hot exhaust manifold.
212F is what water boils at. It's not really that hot when thinking in terms of an engine.
I'll pass on this one myself....

[metalshark]

Originally Posted by texkid

Update:

Yes, I had the circulation backwards.

However, I did some more research. Insulating the high pressure side will not improve cooling. Some mechanics sites say it'll do nothing....others say it'll put more pressure on the compressor, and blah, blah, blah.

Personally, I have not seen ANY positive results on insulating the High Side. In the meantime, I am going to research for insulation that withstand higher temps.

You don't want to insulate the High pressure line. Doing so will cut the sub-cooling of the High pressure liquid returning from the condenser and will decrease efficiency and mileage as a consequence.

[Yaris Hilton]

I think if it would make a big improvement, the factory would've already done it.

[bobolinko]

Originally Posted by Yaris Hilton

I think if it would make a big improvement, the factory would've already done it.

That's why I hesitated and waited so long to do it... My thoughts were like yours. However, summer heat is just around the corner, and a FEW degrees make a big difference when you're just above the "comfort zone" temp wise...

My Co-Worker was also skeptical, but after we went to lunch in my car, he decided to do it on his Tacoma as well, and even on his wife's car too. We FELT and SAW the difference and figured it could translate into a better fuel effeciency rating if the compressor would not kick in as often.

At any rate, I like the feel of the colder air blowing on my face while I sit in traffic, waiting to move 15 feet more before the light changes.... LOL

[Yaris Hilton]

Yeah, any improvement's a good thing. Gridlock in summer is grim without AC. Especially when straddling a big air cooled Harley engine.

[YarisSedan]

A/C temp is directly affected by outside ambient temperature. So from different times of the day and different days you are going to get different results.

I get cars in my shop on extremly hot days saying thier ac is not cooling as efficently as before. But yet thier a/c is fully charged. So charging wont make a difference.

[eTiMaGo]

what an interesting idea, can certainly be useful here in our hot hot tropical days, the AC can really struggle sometimes...

I have a friend who works at an airconditioner repair workshop, maybe he can get his hands on the high-temp stuff

[Sodium Duck]

I just sent off some e-mails to companies about their mineral wool pipe insulation for pricing. I'm having trouble finding this stuff.

[CTScott]

Originally Posted by Sodium Duck

I just sent off some e-mails to companies about their mineral wool pipe insulation for pricing. I'm having trouble finding this stuff.

Check out McMaster Carr:

http://www.mcmaster.com/#pipe-insulation/=2hwsny

[Sodium Duck]

NiNjA pOsT!

[Sodium Duck]

Thanks Scott!

How long is this pipe by the way?

Hmm, that site has a 2'x4' sheet for 6 bucks, not bad.

[mrbond]

Fantastic idea! I did this yesterday after I got home, except I used fewer zip ties and employed the use of aluminum tape. With the aluminum tape, the air temperature recorded on the meat thermometer was 37 degrees! Best cheap thing I've done to my car hands down.

[Sodium Duck]

Did you do both lines?

[mrbond]

You mean the high pressure and low pressure? No, just the low pressure going into the cabin. My hands aren't small enough to work with the high pressure lines.

[texkid]

Originally Posted by PK198105

here is what i did:

i covered the rear return line with high temp aluminium tape. Temp resistance up to 180C

Where did you find the aluminum tape? Was it easy to apply?

[texkid]

Originally Posted by PK198105

the local Rona in the vents and ac department. its like regular tape but with aluminium in it. very easy to apply. but gets pretty hot to the touch after you drive for a while

How's the air running? Same as with other setup? Or cooler?