How Important is a Dryer?
Personally I always use a dryer when changing a compressor or condensing unit but as I'm sure many of you have noticed not everyone does. It seems to me that I find more compressors that dont have dryers installed go bad than compressors that had dryers intstalled. But I have no real proof of it. I have seen systems that are quite old and dont have dryers installed and they are working just fine. Does anyone know of any conclusive proof that a dryer increases compressor life? I've wondered does it double the life, just add a little extra life or does anyone really know?
I also assume that if I see a unit without a dryer there is a pretty good chance a vacuum wan't pulled either.
If no trash gets in the system in the first place and there are no leaks and nitrogen was flowed while brazing there is no need for a dryer. Otherwise it's a good idea to install a dryer to catch the crap. I have had driers bust up and clogged up screens and such causing restriction though.
as far as Im concerned the ONLY thing that increases a compressors life is~~~~~attention to detail.
If you do your job right, De-burr the inside of the line set, protect the valves while welding, use nitrogen and pull a good vacuum. Then a compressor should last forever regardless of any filter/dryers.
Now! realistically? A compressor is a mechanical device, therefore it IS subject to failure.
BUT!!!! that is JMHO, YMMV
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Its important. Just like a oil filter on your car. Even manufacturers don't skimp now with 410.
How important? Well that depends on a myriad of variables. Acid level, particulates, moisture, etc.
I have no proof but, I believe a dryer would protect the compressor. If they are maintained compressors would last longer. What I mean by this is, If you have a clogged condenser coil the compressor over amps and runs higher pressures. This could create wax and such in the system. Or if you have low suction pressure because of a dirty filter, You would have some oil return problems and might get some metal shavings that clog the drier. Once the drier clogs you could replace it and all may be well again.
I will see if I can dig up some proof. Obviously manufacturers don't think they're that important because they're sending 15ton compressors with a 16 cu in drier on them. or a 5ton with a 4-5 cu in drier.
I don't have any conclusive proof either, but I know some things.
I've seen systems that had multiple failures of replacement compressors that stopped having failures when suction driers were added. Nothing else different, just suction driers.
I've seen sightglass moisture indicators change from Wet to Dry just by changing drier cores, no vacuum pulled, on rack systems, and the compressors didn't fail. But I can't think at this minute where to lay my hands on conclusive, as in written by a manufacturer, proof that moisture damages a system.
I used to work on domestic refrigerators. Never saw a refrigerator that didn't have a drier, and it seems to me that refrigerators last much longer than a typical HVAC system.
It makes sense to see systems, as they are installed today, fail in spite of having a drier since the usual place to put the drier is the liquid line at the outdoor unit. Slag or oxidation created during installation has to pass through the compressor before getting caught by the drier. I don't know it will leave the compressor. How do metal shavings that reach the crankcase or are created in the crankcase get pumped out?
I'm more inclined to have no opinion regarding whether or not a vacuum was pulled when I see a system with a drier. I've seen apartment units with driers but no vacuum pulled because the maintenance man believed the drier removed the need for a vacuum. And I have said something to this effect more than once, "I know the system is tight because of the pressure test. I can't wait for it to reach 300 microns. The drier will catch the rest."
Moisture creates acid in system.Suction line driers should be temporary and can create more problems if left in. A drier does not replace a proper evacuation, it does not remove noncondensables. I believe in replacing or installing a filter drier any time the system has been open. Call it cheap insurance.
Although i fully agree with jmac00 "attention to detail" just remember that there are wearable items in the compressor and could result in particals flowing through your system. Ever drain the oil out of a brand new engine or in this case a compressor and see little metal flakes
Originally Posted by SBKold
Last edited by beenthere; 12-05-2012 at 06:17 AM.
Reason: Fixed quote tags
We recently had sporlan guys at our shop for a class. It was great information and driers were a hot topic. Here is a link with a lot of literature. http://www.sporlanonline.com/catch-a...obi=non_mobile
Explore their site it has some neat stuff. There are a lot of selections for different contaminants. I would always add change or replace because you never know what is out there and might break loose.
How Important is a Dryer? Nothing is important until you need it, now what is the purpose of a drier again.
I install a drier everytime I open the refrigerant circuit. Just make sure the arrow is pointing in the right direction!