OT: R-22 in heat pump

"Tom Gardner" fired this volley in news:LK- dnX6USIr9qzvQnZ2dnUVZ snipped-for-privacy@giganews.com:

No, Tom; unless you find an "underground" source, you cannot buy R22, or any other refrigerant that contains florinated compound without an EPA certificate (and usually an apprenticeship or affiliation with a licensed HVAC company). The wholesale guys are really tight about this, too. They stand to lose their licenses if the sell to you.

It is not reasonable that the unit should drain in two years. You have a leak. The correct procedure would be to fix that leak before fully recharging the system (you have to get the pressure up to near-operating conditions to find a "two year leak").

One thing that you might consider, but only if you're a brave soul, is to pump the system down and re-charge it with propane. Propane is _almost_ a drop-in replacement for R-22. It is slightly less efficient, but lots cheaper, even if you buy the non-mercaptan'd version from a gas supplier.

Really, if you try this, you should get the purified dried variety, unless you're also willing to replace your filter-drier (which you should probably do, anyway, after two drain-downs).

Before you squinch all up at the thought of using such a "highly flammable gas" in your AC, consider the toxicity of Chloroflorocarbons in the presence of flame, and also that most European "R-22 type" ACs now use propane as the refrigerant.

LLoyd

Tom, preferably you need license to get the refrigerant.......on the other hand if they don't ask for your license you may be able to get it. I work in commercial refrigeration but I am in southern indiana. Some agriculture equipment and some mobile equipment have used R-22. If you can find the R-22 at an auto store that is fair game. Your guages should have 1/4" flare fittings and that is still used widely except for the new R410 systems which I know nothing about. Commercial systems went thru a major change of refrigerants about 15-20 years ago and have somewhat stabilized. If you can get a 30# cylinder go for it. It will be cheaper to put a little in every couple of years than replace the whole unit. Also if you have it serviced ask if they will sell you the remainder of the 30# can. R-22 is being phased out in favor of the new R-410. No word yet on how or if the 410 will work in the commercial stuff I work on. Something called "new 22" is supposed to be in the works. Good luck with it Lyndell

----- Original Message ----- From: "Tom Gardner" Newsgroups: rec.crafts.metalworking Sent: Wednesday, April 13, 2011 7:48 PM Subject: OT: R-22 in heat pump

The bad news is that you need a license to buy R-22. The good news is that getting the license is incredibly easy. It will cost you about $25. You do have to take a test, but the $25 will let you take the test as many times as needed. Look on the internet for more information.

I have a friend who is in about the same situation. He has a refrigeration tech recharge his system. The last time it cost him $25 including the refrigerant, so it is not worth his getting a license and buying a 30 lb container.

Dan

Tom.

I needed some last year. Just called in and placed an order like I belonged. No questions were asked, they just took my money and sent out my product. I did buy a 30# can. I've done the same with R-502 and (earlier) R-12.

I watched when the pros did it. Then bought a set of gauges off eBay and do my own. I do have a guy that works for cash on the side. Remember Ben Franklin is everybody's best friend.

Karl

I don't know Ben. I do know that George Washington doesn't work

-nearly- as well.

-- The United States of America is the greatest, the noblest and, in its original founding principles, the only moral country in the history of the world. -- Ayn Rand

I think I would find the leak and have it fixed. That is probably going to be the best bet as your efficiency goes all to hell when you have a low charge. Worse, if moisture gets in it wreaks havoc on the expensive bits of your system. On an AC system in a house the whole system is sealed and should not loose *any* refrigerant. (In a car the situation is a bit different as you have seals and gaskets that are expected to ooze a bit over time.) R22 is still commonly obtainable but that could change. Better to keep a supply in the system.

The propane Is not a good idea. While it will work as a refrigerant, you do not have any safeguards built in to prevent mischief. As an example, I assume that your evaporator is in a combined unit with your furnace. If you spring a leak and the gas builds up inside the furnace and then the thermostat calls for heat, there will be a very big boom. Of course it is a sealed system and sealed systems never leak, right?

You might find an A/C guy willing to barter for some brushes or to have stuff machined. Try the barter section on your local craigslist.

Roger Shoaf

RS at work fired this volley in news:7f465d2d-97ac- snipped-for-privacy@g7g2000pro.googlegroups.com:

Y'know, I don't usually shoot back at guys here, even when they're spouting pure BS, and have not a second's experience with what they're explaining. But your post shows you've never even seen a typical home HVAC unit with the covers off, and here you are giving advice on what you _perceive_ might be good or bad.

1) Most home systems are "split" systems, NOT sealed package units -- unless you happen to live in a mobile home, then it's likely the other way. Split systems have the same sorts of potential leaks you claim only autos have. "Sealed" systems have the evaporator, condensor, and compressor in a single package, and all connections are brazed (or, unfortunately, swaged). Split systems often have mechanical connectors in the refrigerant lines. Even when the lines are soldered (and correctly), there are service ports and charging valves that can leak. (shouldn't, but can). Even "sealed" systems larger than a window unit have service ports. 2) Pure, low-mercaptan or mercaptan-free propane is packaged and sold as the refrigerant R-290 (even in the US). It's not used in domestic systems in the US because of the big chemical company lobbies which kept it rejected from the list of acceptable products here, so they could sell their proprietary refrigerants. It's used all over Europe, and poses no more danger than CFCs and HFCs do, just a different type of danger. It's also a _completely_ biodegradable, "green" refrigerant. And it's only a percent or three less efficient than the best azeotropes and near- azeotropic blends like R410A. It's a "drop-in" replacement for R22.

You probably have skills in something, Roger, but HVAC ain't one of your areas.

LLoyd

Then there is the hazard of someone taking a torch to a unit where the charge has not been properly evacuated.

"PrecisionmachinisT" fired this volley in news:xYSdnXy-guzlgDrQnZ2dnUVZ snipped-for-privacy@scnresearch.com:

Ok... so we have poisonous combustion products from one, and a fire hazard from the other. Those issues have been weighed already, and the US is on the verge of approving R-290. Then, of course, you'll have to have an EPA certificate to buy propane for your backyard grill.

LLoyd

Probably not for the backyard variety of propane.

--IIRC there is way too much moisture in it which would be fairly difficult for a non-tech-type to deal with, making "gas and go" from a barbeque bottle a very risky proposition for the average diy homeowner.

"PrecisionmachinisT" fired this volley in news:q9qdnaZWXMPTpjrQnZ2dnUVZ snipped-for-privacy@scnresearch.com:

Interestingly enough, the pre-packaged Coleman propane in the 14oz bottles is quite dry and pure. It has more mercaptans in it than is desirable (they can settle out and "gunk up" machines), but it's been used by amateurs quite a bit for recharging R-22 machines. Not recommended for capillary tube units for the reason of the goo.

I think they scrupulously dry it because the steel bottles are not corrosion-treated on the inside. Any moisture present would tend to acidify (like it does in an AC), and attack the bottles from the inside- out.

LLoyd

-

LLoyd,

I went to HVAC school. Even this does not make me an expert. But let us for a moment think about a home with the furnace in the basement, the condensing unit sitting on a pad outside the home. If a refrigerant leak was to occur in the evaporator located inside the duct there is no provision to detect this prior to the ignightor being engaged. In this example you would have an air fuel mix inside the duct and you would have a big boom.

I did a quick google search and found R22 in 30lb. cans @ $226, that is a cost of $7.54 per lb. Assuming that Tom needs 5lbs that is $37.67. If the HVAC guy charges double that is about $75.

Now I am not sure what the R290 will cost but unless someone is going to pay Tom to use it the most he could save is the $75. On the other hand reading from the Tecumseh guidelines he might need a new compressor they say:

"Compressor selecti "Expansion valve selection: The expansion valve manufacturers have designed product specifically for use with R600a and R290. Consult them for their recommendations."

Tecumseh further says:

"Since special safety considerations must be applied in the design of equipment using hydrocarbon refrigerants, such as R600a and R290, Tecumseh does not approve of, endorse, nor recommend retrofitting existing systems with R600a and R290."

"Special safety considerations". All to save $75 worth of R22? If I understand you correctly, that this is a good thing for Tom to consider. Have you checked to see if Tom's compressor is compatable with propane? His expansion valve?

You are entitled to your opinion, I do not claim to be an expert on retrofitting a home AC system designed to run on R22 to R290. I suspect however that the engineers at Tecumseh probably know their stuff.

So while I admit that my level of training does not make me an "expert", I think that Tom would be better off paying for a service call and having the AC guy fix his leak and charge up his system.

You might also read this:

Now consider the amount of propane refrigerant in a refrigerator vs. the amount in a home AC system. All to save $75?

So perhaps I am a blowhard, but I would prefer not to risk my home or Tom's home just to save a few bucks on gas.

Roger Shoaf

or maybe new connectors on propane tanks?

RS at work fired this volley in news:906c3412- snipped-for-privacy@w7g2000pre.googlegroups.com:

Sure... I agree with that completely, but THAT wasn't your objection. Your technical objections have all been weighed by the _real_ experts (neither you nor me), and they have decided that R-290 probably will be accepted for domestic HVAC equipment within a few years.

Is it worth his cost to do it himself? Might be... Tecumseh has to justify selling new Ex-valves, compressors, and reversing valves somehow. Designing them _just_so_, so they're _optimized_ with either 600a or 290 (can't be both, they have different curves) will make them money.

But the truth is, propane works just fine in most R-22 systems, with the exception that mercaptan loading must be low in capillary tube systems, and the efficiency of an expansion valve system may drop off 3-5%.

Had you originally argued that it wasn't worth his effort for the price, you'd have gotten no argument -- but you started objecting on technical grounds.

LLoyd

"Stormin Mormon" fired this volley in news:io7tb2$48h$ snipped-for-privacy@dont-email.me:

Yeah, like non-condensibles in the system.

High high, and high low, too, and no cooly.

LLoyd

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 Dan

I was wrong. I did not remember correctly. The easy to get license for $25 is only good for small appliances. Not good for central air conditioners.

Dan

Tom, I forgot to mention that if you get the refrigerant and try to charge it yourself........look on your manifold guages for the R-22 scale (that gives you the temperature of the refrigerant at a given pressure) .The suction side (low pressure side) needs to be above freezing (32 degrees F) (perhaps 65-75 psi) high side will be 200-300 psi depending on a lot of things, house temp- ambient temp-condenser coil being clean etc. I am not encouraging or discouraging you from fixing this yourself. I know you are not afraid to tackle a project. I just feel better if you are informed. If the condenser (outside fan) is running and the condenser is cleaned and the inside coil is clean and free of ice, and to get the suction pressure above freezing, the head pressure (high side) goes much higher than 300 psi........please call the pros and find out what is wrong. Feel free to send an e-mail on or off list. I will help if I can. I usually check e-mail in the evenings. Good luck Lyndell

Thanks! I did call my bud, he's in Texas now, and he said to tighten the Schrader valves and replace all the caps with new ones with O-rings. He said the odds are 90%+ that's where the leaks are. My manifold gauge set doesn't have a scale for R-22 so I'll have to use the pressure reading and a chart. He also said he'd walk me through on the phone any time. Another bud called his bud and he dropped off a full tank of R-22...he mentioned he might be able to use some brushes. Imagine that! It's good to have friends! I'll let you know how it all unfolds as soon as we have a nice warm day. My bud said to do the job when it's at least 65 degrees outside, it's a lot easier.

I was wrong. I did not remember correctly. The easy to get license for $25 is only good for small appliances. Not good for central air conditioners.

Dan

A bud dropped off a 30 lb cylinder. Wasn't that nice?