I cut down the cool down time in half for the A/C. In the afternoons in south Florida, it gets into the 90's and the air condictioning takes some time to cool off.

Checked the charge in the system and it was ok. Wraped all the A/C lines with tube insullation and tied it in place with zip ties. It now cools down in half the time and stays cooler all the time.

 

Good idea...I did that several years ago...sounds like the same way you did.

Tom Piper

 

Any pics; great idea!

 

Also, for you auto climate control panel peeps, you can reset your A/C's pre-programmed defaults by pulling the Radio and Courtesy Lamp fuses for one minute, then replacing.

I sometimes forget to do that after I unhook my battery to clear codes or other maintenance, then wonder why the A/C function on my Auto Climate Control doesn't blow as cold as it should.

Pulling the fuses for one minute (as mentioned in my owner's manual) always does the trick.

 

Thanks.

 

Are you talking about the black, foam insulation similar to the ones found on residential/commercial central air units?

I was gonna' do that but had possible fire safety concerns. Does that stuff hold up well to engine heat?

 

I am interest in what type of insulation you used - any issues about condensation being traped in the insulation and rusting out the pipes?

 

That's what I used -- black foam.

Mine has been on for about five years with no problems.


Tom Piper

 

I've had no problems in about five years.

Tom Piper

 

Yes, it is residential/commercial central air insulation. Its about $1.49 at Lowes for six feet. And so far it holds up well under the engine heat.
I also used plenty of zip ties when going around curves in the tubing.

 

I don't know this for a fact, but I use the black zip ties because I think they are more durable.
I know they hold up better in sunlight -- I think UV damages the white ones.

Also, you don't want to pull the ties too tight -- just enough to hold.


Tom Piper

 

Did you wrap both lines in insulation or just the liquid return (cold) line?

I'm no HVAC expert, but what purpose does it serve to wrap the high pressure (warm) line in insulating material?

 

I wrapped just the low-side line.

Tom Piper

 

No chance of that, they are aluminum.

 

An engine heat fire was my only concern. Thanks, guys. You just gave me another neat weekend project!

 

One thing that should be noted is make sure you get central ac insulation and not water pipe insulation. I'll have some on the 85 this weekend. I use this same stuff on my 77 around the radiator and it works great.

 

What were the operating pressures before and after?

 

I did this about 5 years ago, I never checked the before and after pressures.

My motivation was:
Why waste the cool return flow from the evaporator to the air under the hood?
I wanted to use it to keep the compressor cooler hoping for an increase in life.


Tom Piper

 

I've got a thermometer. I'll post my ambient vent temp readings after I perform this mod.

With 90+ weather on the way this week, I couldn't pick a better time than now to do this. The principle is sound.

 

Compressor durability is a function of lube, not pressure wherein it simply shuts down (too high or too low). Negative pressure - vacuum - can effect the shaft seal - but that shouldn't happen unless it's horribly plugged up or if there's moisture (improper evacuation and charge). Design is sufficient to maintain an average high side of about 200 psi, which keeps the Evaporator just above freezing - 25 to 30 psi under allmost all conditions. Since pressures determine vent temps, a significant drop in pressure, would indicate its overcharged, or airflow is restricted through the evaporator (and after 10 or more years, the factory filter may be plugged up) or airflow is restricted through the condensor. There's a reason the line isn't insulated by the OEM's - it traps moisture which leads to corrosion, most often, connections that won't come apart when servicing the system (though when I swapped out my main hose, it's because it was welded to the Accumulator and it wasn't insulated). And much below 60 degrees, you need engine heat to warm it up -that gets your Defroster working sooner. Given the age of our Vettes, there's probably little to worry about if you do this - most are overdo for service or will simply give up a component because of age anyway. I'd just take a different approach and check the pressures (which for a lot of our cars, shows that it really needs a partial or complete rebuild).