Restaurant reach in cooler

[Stormin Mormon]

Last couple days, I've had the chance to work on a reach in cooler, at a restaurant. Under a counter. The old guy who runs the place says it needs freon every six months. The aluminum evaporator gets wet, and probably has a lot of pinhole leaks. I checked all the fittings, and find no leaks at fittings or braze joints. Metering device is TXV, and the system has a receiver.

The system is probably 30 plus years old. The evaporator is above the compressor. About 8 inches higher, and maybe six feet to the side.

Since the evaportator his higher, perhaps oil return isn't an issue. Since it runs off a TXV, maybe it will adjust to the lower heat capacity of 134a. Has anyone else tried such a conversion? I'd much rather be feeding it 134a, compared to some other gas or blend.

[Noon-Air]

The thing is 30 years old.... they don't last forever. time to replace the POS

[Stormin Mormon]

The question is.... if I put 134a into an old R-12 system, will that cause any big problems? Oil return, or not supplying enough juice, or starving the evaporator (and not cooling the box) or, anything else?

It's leaking some where, cause the box needs refrigerant added every six months.

[Stormin Mormon]

I agree with that concept. Problem is, that NYS economy is really bad. And there isn't enough cash flow to justify a new cooler.

[olddog]

But there is enough $$ to keep fixing a 30 y/o cooler? Sounds like poor logic.

od

[Stormin Mormon]

Sounds like short term thinking. Few bucks now, instead of a lot of bucks now. Over the years, the new cooler is probably cheaper.

[olddog]

In the mean time the guy is using a cooler that may or may not work. When the public health is at stake I think he should do the right thing and have equipment that is working properly. Just sounds like some cheap restaurant manager trying to turn a monthly profit so he gets a bonus.

IMHO

od

[Stormin Mormon]

Taking his report, and running with it. That means he has a cooler full of warm food twice a year.

[Don Ocean]

If its an R12 unit.. Use R409, R414B, R416A or a dozen other alternatives. Slip in an ounce or so of Pag oil per manufacturers specs. Go to Atofina,Icor, or other pertinent Websites.

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[Don Ocean]

Yes! There are drop in replacements. Tghere are minisculibility issues that are resolved by using a drop in. Chemicals to cleanse mineral oil out and to replace with PAG is close to $100 your cost, plus lost time.

Oil return, or not

Find the leak. Fix the leak. do the usual evac and fill and be on your way. If the system is really old and defunct replace it with new and more efficient.

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[Stormin Mormon]

Hotshot, like 409a, needs to be dispensed as a liquid. It's a three gas blend. I'd ideally like a gas that is a single gas. Like 12, 22, 134a. So I can charge the system wtih vapor.

[Stormin Mormon]

Looks like that's going to have to be the best answer. I put in 409A the last time, see how long that charge lasts. It is looking like I'd best to plan on adding several ounces of

409A every couple of months. Since the charge weight is well under 50 pounds, it's legal to keep topping it off.

[Stormin Mormon]

That figures. I did beep all the fittings and braze joints. No leak found. So, it's very possible some tiny leaks in the evaporator. The old guy who runs the place would rather buy a couple ounces of refrigerant couple times a year, instead of replace the evaporator.

[HVAC]

Please give the name and city which this restaurant is located.

[Steve]

Then your not charging enough for refrigerant, or your time. The owner will have to feel pain in his wallet before he *does* anything. At the same time, your not charging enough to replace the evap on that old POS. You got to charge enough to make him *WANT* to replace the system, and be happy about writing the check for replacement.

[Steve]

Just because its "legal", doesn't make it right.

[TheKing]

PAG oil if for automotive use. POE oil is the correct oil for 134a in refrigeration.

[Stormin Mormon]

That sounds like valid business advice. Thanks.

[Don Ocean]

How are you charging R134A? As for dispensing any mixed gas.. send as a liquid to the gauges and then use an inexpensive device on your gauges to transfer it to a gas as it is charging. In many cases you can charge by liquid by carefully charging slightly over the target pressure. 20 lbs over in automotive seems to work for residential/commercial as well. Weighing it in is the best. It is time you learned to charge with liquid etc.

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[Stormin Mormon]

How are you charging R134A?

CY: I havn't yet used 134a on the restaurant cooler. I'd like to, it's so much easier to charge.

As for dispensing any mixed gas.. send as a liquid to the gauges and then use an inexpensive device on your gauges to transfer it to a gas as it is charging.

CY: I've got one of those "chargefaster" orifice gadgets. I'm not all impressed. Tends to freeze over, and shut the flow down.

In many cases you can charge by liquid by carefully charging slightly over the target pressure. 20 lbs over in automotive seems to work for residential/commercial as well. Weighing it in is the best. It is time you learned to charge with liquid etc.

CY: I do have a scale, and do try to charge by weight. With a sight glass in my gages, I can feed liquid, hold the gages on their side, and the vapor goes into the blue line. It's a bit of a PIA compared to open the tank and stand back and watch.