Question about cars AC

[DrDusty86]

I was thinking about putting rubber hose around the metal line (low pressure??) side of the AC. This sweats and gets super cold..It's normal I take it. So, my thinking is to insulate it from the engine heat to make it more efficent. I would slice some heater hose long ways and slip it over the line.

I would think this could potentially lessen the load on the AC system making components last longer and make the vents a few degrees colder.

My logic is somewhat basic for this, think of a cold beer can in 80* temps, it sweats a lot and gets warm FAST..eeewww warm beer..lol NOW, put the same beer can in a cuzzy to insulate it..it stays colder MUCH longer.

Would wrapping my metal AC line with heater hose make the system last longer and provide cooler vent air?
Dusty

 

[SteveSRT8]

I have used the split foam hose type insulation in many hot rods. It really works, and it's very cheap. It's about 1/2 inch thick foam, excellent insulation qualities.

get it at a home improvement store for next to nothing.

Note this only works on the expansion side.

 

[Drew99GT]

Some people think it's a waste of time, but many cars have the low side line insulation from the factory.

The argument against doing it is the low side line coming out of the firewall is past the evaporator and the entire A/C circuit is a close loop phase change.

But, I have read where people have dropped their vent temps by a degree or two wrapping the line.

 

[Dakota1820]

i used the foam insulation it helped some not a lot but it was only a couple bucks so it wasn't a bad improvement for the money

 

[The_Jeff]

This was hashed out here before and there were concerns about trapping condensation and causing corrosion.

But then you see stock systems do it.

 

[HTSS_TR]

Cost vs benefit: Cost is very little in both money and time, benefit is hard to verify.

Since cost is so low, I would try it.

 

[JHZR2]

My 30 year old MB cars, which have original AC and do not need to be topped up regularly (at all) have insulation on the lines where they cross warmer sections of the engine bay. On smaller cars this may well make sense.

I'd prefer to have something that would bond to known good/clean metal, versus just plain pipe insulation, as trapped moisture is a concern. Also the type of insulation used would be a consdieration also so that moisture cannot be trapped or mobile in the insulation.

Id prove the concept with some of the better closed-cell rubber insulation from HD or lowes, and if you can actually tell the difference under identical, controlled conditions, then id look to get the right materials to do the job correctly.

let us know!

 

[mechtech2]

Yes, insulate the lines from ambient engine heat.
The foam split tubing used for home water lines works better as an insulator than heater hose.

 

[Eddie]

Get the kind that is split the length of the insulation and has glue, so you slip it around and press together. I did need to use wire ties in some cases where the bends were sharp.

 

[simple_gifts]

+1 on doing this on small cars.

I noticed on the new Camry my brother rented the cat is virtually 6 inches from the exhaust manifold, right behind the radiator.

This bodes well for very high under hood temps.

 

[sciphi]

Thanks for the idea! I'll have to do this on both cars.

 

[DrDusty86]

It seems like foam would disintegrate from the heat, No??

Also, will it put more stress on the AC system from doing this or will is be easier on the system?

 

[yonyon]

One of my cars has a low side pipe that runs over 12 feet from one junction to then next. I wrapped most (there's less than a foot uncovered) of that length in the split foam pipe wrap from Home Depot in hopes of having slightly lower outlet temperatures. I didn't get any temperature drop at all, but I got a load drop. Acceleration with AC on is noticeably better and I expect that means I'm burning less gas.

Of course, this car is probably of a very different configuration from yours, so...

 

[JHZR2]

Well remember that cooling is really from the phase change, and so if the expansion valve has a fixed orifice, I suppose only so much can transit through at a given pressure and flow.

So you may be stuck there.

But youre right - less phase change/evaporation in the lines, so more heat can be removed in the evaporator longer before the pressures trip the compressor... That's sensible to me.

 

[DrDusty86]

JHZR2,
Do you think this is better for the system..IE lessen the load on the compressor and will make it last longer?

Not only am I looking to lower vent temps, I'm wanting to make the compressor and clutch last longer. Any little tricks would be helpful.
Dusty

 

[yonyon]

What is your car anyway?

Originally Posted By: JHZR2
Well remember that cooling is really from the phase change, and so if the expansion valve has a fixed orifice, I suppose only so much can transit through at a given pressure and flow.

So you may be stuck there.

But youre right - less phase change/evaporation in the lines, so more heat can be removed in the evaporator longer before the pressures trip the compressor... That's sensible to me.


Fords would be the notable exception there. The replaceable orifice tubes come in five (I think it's five) different sizes with the most common color orange being the middle size. If one wishes to go larger than even the largest size, there's still the option of going to a GM orifice tube which will also fit. An older system may also have an adjustable low pressure cycling switch which adds one more means of tuning the system. Unlike a thermostatic expansion valve or variable displacement compressor, it's still a static tune, but tuneability is tuneability.

 

[DrDusty86]

This is my Zx2 Escort... it blows 43* and the compressor is quiet..just wanting to keep it quiet and extend the life of it.. oh drop vent temps too.

 

[yonyon]

What year?

 

[DrDusty86]

99'

 

[yonyon]

I think that would come with a red tube. A blue tube would be larger and orange would be smaller. The larger tube might give better performance on the highway and the orange at idle.