DIY: A/C Insulation

[texkid]

First off, I really should THANK Echo-hrs for the idea. If he never mentioned in the first place, I probably would've never know to do this to my car. I went to my mechanic for some help. After taking a look at my car, he definitely agreed that the Low Pressure line needed to be insulated.

I purchased a meat thermometer to get a reading on how its running BEFORE I started doing the insulation. Below is the reading with the A/C set to (4) on Recirculating, with all vents open; driving from work to home (roughly 20 minutes) ABOUT 50-DEGREES


Here is temp, with the car in the drive-way and windows half open. Its 120-freaking-degrees!


AND FINALLY, here is the temp AFTER the insulation driving for 15 minutes. A DROP OF ALMOST 10-DEGREES!



So, without further delay, on with the DIY.

Disclaimer: I am not responsible for what happens to your car. Do this at your own risk.

Tools:
- A pack of foam pipe covers (.75 cents at Wallmart)
- A pack of 6 inch wire ties or whatever you call them
As far as the zip ties are concerned, DO NOT tie them too tight like I did. Just enough tension to keep them in place is all that is needed.
- A meat thermometer
- A couple bottles of water
- SHADE!

Instructions:

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.






next: get your foam pipe insulation and check to see if it fits. If its too loose, you can trim off a bit. But just a BIT!

-Start at the firewall end since it is most difficult and cramped part of the job. At this point, it is recommended that the engine is cool to touch. I singed a couple of arm hair before I realized that. LOL!


-Run it as much as you can, once you hit that big, "drum" looking thing, cut and start tying it down. As far as that "drum" looking thing, you're just going have to get creative and find a way to cover it. But it does make a difference when you do.
As far as the zip ties are concerned, DO NOT tie them too tight like I did. Just enough tension to keep them in place is all that is needed.


-For the other side, grab a piece and run it from the front side and thread it under the engine mount. Tie that down very well and make sure nothing can hit the belt or the alternator.




-For the rest of the low pressure line, just keep tying it down until you hit the rubber hose. I shouldn't have to tell you this, but cut holes where needed such as the low pressure valve and that do-hicky you see below.


-AND YOU'RE DONE! Cut off the excess straps so they won't get tangled into anything.

[texkid]

Originally Posted by echo_hrs

Cool...Glad that it worked!...

Cheers

Thank-you good friend.

One thing I did notice is that the air seems to get cold faster at startup than before and it actually feels colder than before. Like my old Escort.

[BailOut]

That's a nice write-up but wouldn't it be easier to use a foam and foil wrap tape than zip tying ever few centimeters?

This is what I use on my hot water pipes in our garage, and on the above-ground segment of our sprinkler system:

http://www.homedepot.com/webapp/wcs/...3+90063+531155

[cali yaris]

that is an A+ DIY - thanks for posting it. Can I copy it to my e-magzine? I think even other car owners could figure out how to do the same thing.

[Sodium Duck]

Very good idea. Will be doing this on the weekend!

[texkid]

Originally Posted by PK198105

texkid, you kinda went apecrazy with the zip ties, you want the wrap to be resting on the pipe and not be squeezed you are taking out the air in the foam and therefore the insulator.Air is the best insulation. ideally you want it to be tight enough to not move but loose enough so there is air in the foam. ill post my pics when i get home

You are right. I need to redo it. I'll change the DIY to reflect that.

Originally Posted by BailOut

That's a nice write-up but wouldn't it be easier to use a foam and foil wrap tape than zip tying ever few centimeters?

I was thinking that. But my biggest fear was that this whole idea wouldn't work in the first place. And so I figured I shouldn't invest too much into it. The zip-ties were a good a idea at the time since if I were to screw up or it didn't work, it would have been easy to just cut the ties off.

Originally Posted by cali yaris

that is an A+ DIY - thanks for posting it. Can I copy it to my e-magzine? I think even other car owners could figure out how to do the same thing.

Sure, I don't see any harm in it.

[toast]

This is a great idea. I had forgotten that I had done the same thing to my old ranger many years back and it worked great. That beast was 14 years old when I got rid of it and the a/c was the only thing that still worked properly on it. +1 on the excessive zip ties though. All that crushing will reduce the insulation ability some and it's just more work than needed.

[AlexNet0]

that is a great idea, I always think about how the AC should be colder during the hotter days here in the summer.

[texkid]

Originally Posted by PK198105

i can now verify this as I did the same thing today during my break. It works very well and the air coming from the vents is definitely colder than before, also the interior cools down faster, now you can set your dial to 2 and be content as it will keep the same temperature.

We could also insulate the other pipe for even quicker cooldown but that is to be experimented further.

It would interesting see what temperature readings you're getting since you insulated the pipe past the rubber hose. If it is cooler than my reading then more foam insulators is in order!

If you want, you can replace my "AFTER" images with yours since I put on the zip-ties too tight. Just a thought.

[auxmike]

Is this a safe practice?
If so, why did'nt Toyota do it in the first place?
Wonder if that foam could MELT with the heat under that hood.....

[YarisSedan]

Lot of things the vehicle should have come with from the factory but they only install what is bare minimum required to cut production costs. Like for example all yaris should have a swaybar from the factory but it wasnt cost effective for a basic commuter car

[texkid]

Originally Posted by auxmike

Is this a safe practice?
If so, why did'nt Toyota do it in the first place?
Wonder if that foam could MELT with the heat under that hood.....

-Is it safe? I dunno. I am assuming as long as it doesn't come in contact with the belt or other moving parts, it'll be ok.

-Why Toyota didn't do this? Heck if I know. Costs? Research? Maybe they thought 50-degrees was enough? One thing I do know is that "most" of the domestic cars I've seen have the rubber hoses. I think maybe aluminum pipes last longer than rubber hoses?

-Melting foam? Probably not. That PCV line is foam as well and in some places comes in closer contact to the heat of the engine.

[YarisSedan]

Hmm i think i may do this mod but making it more clean and factory looking using bailouts idea.

[CTScott]

Originally Posted by auxmike

Is this a safe practice?
If so, why did'nt Toyota do it in the first place?
Wonder if that foam could MELT with the heat under that hood.....

I was thinking the same thing. There are high temp and ultra high temp pipe insulations, but they are pricey.

Polyethylene pipe insulation (which is the kind you get at home improvement centers) is only rated to 180F or 200F.

Silicone pipe insulation is rated for 500F, mineral wool can handle 800F, Flexible ceramic at 1500F, etc. McMaster-Carr has a wide selection of industrial pipe insulation.

The other issue besides temp rating is fire rating (ASTM E84 rating). We ran into an issue UL testing a battery pack because of insufficient rating on the closed cell foam we were using the keep the batteries from banging around.

[auxmike]

Wonder if it affects the warrentee too.....

[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

[texkid]

Originally Posted by CTScott

I was thinking the same thing. There are high temp and ultra high temp pipe insulations, but they are pricey.

Polyethylene pipe insulation (which is the kind you get at home improvement centers) is only rated to 180F or 200F.

Silicone pipe insulation is rated for 500F, mineral wool can handle 800F, Flexible ceramic at 1500F, etc. McMaster-Carr has a wide selection of industrial pipe insulation.

The other issue besides temp rating is fire rating (ASTM E84 rating). We ran into an issue UL testing a battery pack because of insufficient rating on the closed cell foam we were using the keep the batteries from banging around.

Hmmm....

At what temperature does the engine block reach when its running at normal range?

On the packaging, that the foam covers came in, it states that it is safe for temperatures as high as 212*F.

If I need better insulation, that's fine with me. I am willing to make a compromise and pay a little more so long as I am guaranteed that it'll keep the A/C cold.

[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.