Kiln Compressor Replacement

[GeneWengert-WoodDoc]

A comment for the younger folks...R22 and R12 were amazing refrigerants as they were efficient gasses, operated over a wide temperature range,  and provided for wonderful lubrication as well.  They were also inexpensive.  They also were really good at destroying the ozone layer miles above the earth's surface.  

The replacement gasses provided good operating characteristics, and some even worked at much higher temperatures, without the negative ozone effects.  But the newer gasses did not provide the same outstanding lubrication, which means compressors now had a shorter operating life...but their life was still quite long.  We were spoiled by the the thirty years and longer life with the previously used gasses.

To encourage people not to use R22 and R12, the government put a heavy tax on them making them more expensive than the replacement gasses, and required a license, plus required old compressors to be handled carefully so any old gas could be recovered in a environmentally safe manner.  

Unfortunately, so-called developing countries wanted to use the old, ozone depleting gasses from a cost standpoint...and they did and they do.  It makes electric compressor household refrigerators and air conditioners much less expensive.

[K-Guy]

Stan, in the even that I ever need to replace the refrigerant in my 2003 vintage L200, what would you recommend as a replacement?

@scsmith42 
Better to wait till you need it. What's still on the market or easily available to may change. The best to use in my opinion is R-416A because it does the work at lower pressures than others. On the other hand, some claim they get better performance out of the R-134A.

[Al_Smith]

I suppose there are pros and cons regarding any type of refrigerant .Just think if it were all ammonia systems .Talk about stink !
Being a one time submarine sailor from my training I know that freon and oil can be a killer .Turns it into phosgene gas =grave yard dead .
I've heard the heat from a cigarette and freon can be deadly also .--just a word to the wise---

[YellowHammer]

FYI,
This stuff is the best I've used for finding leaks.  It's essentially a polymer syrup that when sprayed on a fitting will show the tiniest leak.



 

[Al_Smith]

I've got a sniffer myself,it works .

[GeneWengert-WoodDoc]

I have heard from a lot of people that like  R-134A. 

[YellowHammer]

The standard building air conditioner systems have a much milder requirement because they stay at a much narrower range of operating temps.  So thensystem has to work within a dwadbnd of typically 3 or 4 degrees, say 68 to 72 degrees.

R134a is an automotive refrigerant for much higher temperature and harsher environment, such as a vehicle parked in the sun in the summer at 120F that need to be brought down to 70.  So it can handle the typical scenarios of DH kiln drying, I.e. a wide range of operating temps.  

It also seems to have a lower precursor at higher temps, so allows the L53 compressor to operate at higher temperatures, saftely without tripping the high pressure safety switch.  

[Al_Smith]

Oh I can tell some stories but will only mention one .First I'm not an expert but over about 50 years have done the electrical work on huge industrial applications.The granddaddy of all of them was an ammonia system  on a turkey processing plant in St Henry Ohio about 35 years ago.

The main compressor was 500 HP  with 4 100 HP that could be staged in and out depending on the load .It had a blast freezer that could fast freeze 3 tons of turkeys to 30 below in half an hour .The liquid line on that thing was 5" .To charge the system it took two tanker trucks of ammonia .

I didn't like the contractor and had no use for the foreman but agreed I'd stay long enough to get the system on the line which I did .The turkeys were to start arriving the next week after I pulled the pin and this turkey went on down the road . I could work any where for anybody but I wasn't going to deal with that .Yuck !    ;D

[scsmith42]

Stan, in the even that I ever need to replace the refrigerant in my 2003 vintage L200, what would you recommend as a replacement?

@scsmith42
Better to wait till you need it. What's still on the market or easily available to may change. The best to use in my opinion is R-416A because it does the work at lower pressures than others. On the other hand, some claim they get better performance out of the R-134A.

Thanks Stan.  

[xlogger]

Robert on the first picture that shows your frosted line and drips on your coils was your kiln empty? I can't get my to do that with wood in there and plenty of humidity, my glassed fog up when I walk in. I get very little moisture non my coils with a little drip but nothing coming out of hose to outside (wood showing 10-12%). Stan now thinks maybe my compressor is not running as good as it should. Like you I'm tried of pay my guy to come out, might be cheaper to get another unit.
Stan, I took my amp reading on wires and left you a message yesterday with reading I got if I did it correct. Do they sound right?

[YellowHammer]

Yes, the kiln is empty, and the water is coming from just ambient air with the doors open.  I've never recharged the system where the line didn't frost up, indeed, thats how I know its working correctly, and I've never closed the doors and called the job done without water dripping into the catch pan and running out of the catch tray.

So here in Alabama, both in winter and summer, when a charge is weighed in, frost will form more and more as the freon goes in.  It happens while charging, real time.  When I'm at full charge, the frost line should go right to the bulkhead, and thats where it should end, so as not to freeze up the coils, but to get maximum condensation.  

Then, within a matter of minutes, I will see water condensing on the coils and by the time all the tools are put up, the water is dripping.

I'm not sure how to troubleshoot the performance of the compressor, mine failed completely, it just stopped working, so was easy to identify as a problem.  I assume that a lack of compression would be a common failure characteristic, though.  

The compressor isn't too expensive for this unit, and I got it from Nyle, but I understand how the house calls from the HVAC guys can really eat up the cash.  Luckily, I have some help, my regular guy lives just down the street and my nephew-in-law is a certified HVAC serviceman and instructor, and his family owns a large HVAC supply place.

[xlogger]

Talked to Stan again today, he suggest recharging it again. This time put in 400# pressure and look for leaks. We did 200# last time and it held there for about 15 minutes so he put in 20 ozs of 134A. It seem to be working but in a few hours not so good. I'm going to unload the kiln this time and take the front panel off and check it again  >:(.$$$.
On what you said about checking out the compressor I check the amps and #9,10,11 wires and told Stan. He said amps were correct so ruled out a problem with compressor.

By the way Robert did you cut out the bottom of your new one to circulate more air?

[YellowHammer]

These little leaks are a bear to find.  I've used a freon sniffer, soap bubbles, professional leak polymer which was the best, and also propane torches as the freon makes the flame turn green.

You could also ask your guy to go ahead and make sure he puts more oil into the system because it gradually bleeds out.

So very closely look for the traces of that oil, it will make the copper tubing look a little wet.

My new kiln will come in Monday and I will cut a hole in the bottom.