kat09

I'm new to forum. I've read on here a lot of guys are fooling w/ their A.C. systems,the one thread is 17 pages long about insulating a line!! I'm a retired heavy equip. mech. I've got a link here for you. http://www.rdac.com/resources/product-literature

STingray1300

Boy, I wish I had the time to peruse through all that...

Simply put, get some 1/2" foam pipe insulation and install on the cold a/c line. It does help.

But if you've got any pointers, I'm all ears!

Phill1060

That was a fun read thanks! So do we have a expansion valve or accumulator system?

jgohlke

It was an interesting read. The way it works is very counterintuitive if you don't know anything about it and you just look at, feel the hot and cold bits and try to use some common sense to figure it out.

Thanks for posting.

gwpfan

It's more than about insulating a line, but yes that's the just of it.

Some of it was education, such as what an accumulator does, but the link to the manuals is very nice, I briefed it, but it all seems there. Thanks

STingray1300

Did you mean gist ?

Sorry, I just need clarification.

mrgooden

I would hope we have an accumulator, never worked on an AC system without one. As for an expansion valve, it all depends. The last AC I used to maintain used 125LBS of R22, had 3 Evaporators, 1, condensor, and 8 expansion valves.

Richard

Al Kohalic

Lol, we hold A/C training/certification classes every year for our customer's heavy duty technicians and even for people in our own dealership service department. The classes are actually taught by a RedDOT factory rep since that is who we get our products from and re-badge them in our own label. Every time we hold a class, it is quiet funny to see how little so many of them know about HVAC yet they proclaim to be know-it-alls. Their basic answer to any HVAC repair work is to just replace the compressor when a $3 orifice tube that was clogged was the issue. It also amazes me how many of those know-it-all technicians(usually the young ones) will over fill an HVAC system with refrigerant thinking more is better when they are actually making it worse. I actually quizzed one of them before the class asking him if I should add store bought refrigerant that claim to make my A/C colder. The dumb-*** actually said yes, and I actually enjoyed telling him why he was wrong since he tried to belittle one of my parts guys in front of a customer. I am not against technicians at all, but after working with just about every heavy duty truck make along with working at Cummins I can honestly say that not every technician knows everything especially the young ones that act like they do. Usually in the heavy duty world, or at least the dealers that I have been at, a technician will speciallise in one certain area like engines, drive train, PTO pumps, or electrical. We have very few jack of all trade technicians and even they will learn a thing or two from the guys that specialize.

As far as insulating the low side line, the objective is to keep as much engine bay heat from soaking into the metal hose before it gets into the evaporator where you want the heat to sink in. Just as heat will flow into the ice cubes of that drink in the diagram of the links you posted, so will it sink into the cold metal low side hose. Insulating the line is just a way of keeping the freon from the compressor to the evaporator as cold as possible before it goes into the evaporator. After all, an evaporator itself is a bunch of small cold tubes with fins soaking up heat and exchanging hot air with cold air. The low side metal line going into the cab is just a big cold line that still can soak up heat in the engine bay causing the freons temps to rise before it gets to the evaporator.

STingray1300

Perfect Al...

gwpfan

All the above.

The gist was just.