Micro CoGen.

Refrigeration => compressor driven systems => Topic started by: BioHazard on May 30, 2011, 10:54:26 PM

Title: Refrigerant compatibility
Post by: BioHazard on May 30, 2011, 10:54:26 PM
I'm experimenting with a 10k BTU window air conditioner to make it water cooled and I'm going to have to recharge the refrigerant. It says on the side the original refrigerant is R-22, but does that mean it's the only thing I can use? What is the difference between commonly available refrigerants? I know R-12 is "bad" but can still be found, can I use that, and would it work better? Or for that matter can I use R-134A meant for car A/C systems?
Title: Re: Refrigerant compatibility
Post by: WGB on May 31, 2011, 05:09:01 AM
Look up Hotshot brand.
http://www.icorinternational.com/findreplacement.php

No metering device or oil change needed to replace R-22, thats a big deal.
One thing is A/C in a high backpressure unit, depending on how cool you want your water you might have a few issues.
Title: Re: Refrigerant compatibility
Post by: gregger2k on May 31, 2011, 08:30:05 AM
If you are a bit adventurous straight propane is a good match for replacing R22. http://autorefrigerants.com/22a.htm (http://autorefrigerants.com/22a.htm)
It's pressures are very similar to R22 and it is more efficient. It is a direct replacement.
I replaced the R12 in my Chevy truck with a 70% propane 30% butane mixture and it worked great.
Isobutane is a better single component replacement for R12 though but it is harder to find.

Europe has been using hydrocarbon refdridgerants for a while in there fridges and it is quite safe. GE has even applied for aproval for use in the US http://www.sustainablebusiness.com/index.cfm/go/news.display/id/17030 (http://www.sustainablebusiness.com/index.cfm/go/news.display/id/17030)

I think it is not expensive enough for big business to make money on so they fight approval. Hydrocarbon refrigerants are  enviro-friendly with no ozone depleting and minimal global warming potential. It breaks down in the atmosphere in 6 montha vs 12 something years for R134a.

Greg
Title: Re: Refrigerant compatibility
Post by: mike90045 on May 31, 2011, 12:03:38 PM
Quote from: gregger2k on May 31, 2011, 08:30:05 AM
If you are a bit adventurous straight propane is a good match for replacing R22. ....

Hydrocarbon refrigerants are  enviro-friendly with no ozone depleting and minimal global warming potential. It breaks down in the atmosphere in 6 montha vs 12 something years for R134a.

So, I guess you can still look for a leak with a match ?  The R-22 would put out a flame, I guess propane/butane will enhance the flame ?
Title: Re: Refrigerant compatibility
Post by: BioHazard on May 31, 2011, 02:38:03 PM
Interesting...I've heard about people experimenting with propane refrigerant but I always have the feeling in the back of my mind something is going to blow up. Then again I'm not scared to make my own propane tanks... ;D ::)

What is it exactly that makes a "10,000 BTU" air conditioner 10,000 BTUs? What is the limiting factor? Is it the refrigerant? The compressor? Evaporator/condenser? If I used a refrigerant that claims to be "more efficient", does that mean I'm getting more than 10k BTUs?

I'm actually modifying it so the hot side is cooled with creek water, not making cold water.
Title: Re: Refrigerant compatibility
Post by: Tom Reed on May 31, 2011, 02:42:58 PM
In a well designed A/C system the components are matched, but the primary limit is the compressor HP.
Title: Re: Refrigerant compatibility
Post by: billswan on May 31, 2011, 09:26:34 PM
Quote from: gregger2k on May 31, 2011, 08:30:05 AM
If you are a bit adventurous straight propane is a good match for replacing R22. http://autorefrigerants.com/22a.htm (http://autorefrigerants.com/22a.htm)
It's pressures are very similar to R22 and it is more efficient. It is a direct replacement.
I replaced the R12 in my Chevy truck with a 70% propane 30% butane mixture and it worked great.
Isobutane is a better single component replacement for R12 though but it is harder to find.

Europe has been using hydrocarbon refdridgerants for a while in there fridges and it is quite safe. GE has even applied for aproval for use in the US http://www.sustainablebusiness.com/index.cfm/go/news.display/id/17030 (http://www.sustainablebusiness.com/index.cfm/go/news.display/id/17030)

I think it is not expensive enough for big business to make money on so they fight approval. Hydrocarbon refrigerants are  enviro-friendly with no ozone depleting and minimal global warming potential. It breaks down in the atmosphere in 6 montha vs 12 something years for R134a.

Greg

Yup I am using it in 2 older farm tractors and it works fine.

And yes in my central air in my house it has been in use for about 10 years and no big booms or flash fires.

Probably should not admit that but..............

Now guys be careful just because I am making it work does not mean every one will have no problems.
I just might be classified as adventurous  :o
Billswan
Title: Re: Refrigerant compatibility
Post by: gregger2k on May 31, 2011, 10:22:27 PM
I'm glad I am not the only one ::)
Greg
Title: Re: Refrigerant compatibility
Post by: TimSR2 on May 31, 2011, 11:24:57 PM
All my cars have the RedTek r12A propane/butane/isobutane mix in them for  years now with no problems.

The flammability issue is a red herring ....  all refrigerant gases are full of aerated refrigeration oil and will produce explosive gas if vented!  Might as well just use HC coolants, easier on the environment and a fraction of the price. Dupont may not be happy.....  ;-)
Title: Re: Refrigerant compatibility
Post by: mobile_bob on June 01, 2011, 12:17:53 AM
if your going to use propane, be sure to use a new drier
garden variety propane for the grill will surely refrigerate just fine, but it is not
generally dry enough to keep from iceing up the expansion valve or tube

there is often times a bit of moisture that gets into the mix, which is really hard on internal parts of
an A/C system.

so i have heard, no personal experience with the use of propane.

bob g