Alternative Refrigeration and Refrigerants

[Acuario]

An interesting paper, it almost read as if he was discarding R410A because if its high GWP - interesting that it now seems to be the refrigerant of choice in mini splits.

Another interesting point was (for another thread!) the mention of automotive air conditioners being modified to run on propane - anyone know how this is done?

Acuario

[doug30293]

Originally Posted by Acuario

Another interesting point was (for another thread!) the mention of automotive air conditioners being modified to run on propane - anyone know how this is done?

Propane (R290) is frequently used in auto AC with excellent results. It was a hack for older cars when R12 became unavailable. No modifications required.

I don't know of anyone using R290 in a newer vehicle that was designed for R134A but I suppose it would work. I did read of someone blending R290 into a working R134A system.

There is a research paper on the web describing R290/R134A blends. IIRC, the goal was improved oil transport and the ability to use mineral oil instead of synthetic.

I am currently weighing the benefits of dual compressors against an automotive compressor and inverter drive.
Automotive compressors are certainly durable. I'm not sure how poorly they compare with hermetic pumps for efficiency.

[AC_Hacker]

Originally Posted by Acuario

An interesting paper, it almost read as if he was discarding R410A because if its high GWP - interesting that it now seems to be the refrigerant of choice in mini splits...

Through web searches, I have run across mini-splits that use organic refrigerants that are manufactured in China. I have also come across mini-splits that heat water, and are using R290 for refrigerant, being sold in Australia.

So, I think that the choice of R410a is related to the profit to be made from a patented refrigerant.

How else can the headlong rush over the global warming cliff be explained?

-AC

[jeff5may]

The super-kool, frosty-freez, amped up automotive recharge cans sold in auto parts stores everywhere are basically R134a with varying amounts of R290, R170, and R600a blended in. The higher the performance level, the more the R134 is tainted with hydrocarbons. BOC/Linde has Care 30, a blend of butane and propane, blended for R134 systems.

[NiHaoMike]

Originally Posted by AC_Hacker

So, I think that the choice of R410a is related to the profit to be made from a patented refrigerant.

R410a is a mixture of R32 and R125. The R125 greatly increases the GWP and slightly decreases the efficiency. There was a claim that it reduces the cost in order to make R410a cost competitive with R22 but that's debunked as R32 is actually cheaper than R125. I'm sure the real reason is to raise the GWP in order to allow them an excuse to phase it out once the patents expire!

[AC_Hacker]

For what it may be worth, here are some Pressure Temperature Graphs for some HC gases (also Ammonia) that have been used as refrigerants:

PROPANE (C3H8) P-T GRAPH

BUTANE (C4H10) P-T GRAPH


ISO-BUTANE (C4H10) P-T GRAPH

PROPYLENE (C3H6) P-T GRAPH


AMMONIA (NH4) P-T GRAPH

Best,

-AC

[AC_Hacker]

Here is a pretty cool Stirling Engine project.

Stirling Engine SV2 MKII by Kirk Engines, Inc. - YouTube

-AC

[jeff5may]

Originally Posted by Mobile Master Tech

Your refrigerant should be easy to obtain, inexpensive, easy on the environment and easy to comply with requirements.

The US since April 2015 is allowing flammable refrigerants in many types of equipment and removed the requirement for R290 and R600 to be recovered as described HERE. Other refrigerants would require recovery/recycling equipment, more stuff a hacker doesn't need if using R290.

The reason other refrigerants require recovery/recycling equipment is the potiential environmental damage. Most refrigerants have a Global Warming Potential of more than 3,000. This is the EPA's SNAP APPROVED REFRIGERANT LIST for HVAC. Notice the GWP. R424a's is 2,440. R134a's is 1,430. R290's is "3"!

Many refrigerants would work well with components designed for other refrigerants, but R290 can be had from your barbecue grill or a bottle from the grocery store, plus the flammability is less of an issue than previously thought. R134a is inexpensive and can be had without a license from any auto parts store. Other good possible refrigerants (such as R134a blends, R424a, etc etc) have extra requirements, require a license, are expensive, or harder to get. I'm going to be using R290, myself.

WHAT?? This ruling has been out for nearly a year?? This changes everything! "Ben, why didn't you tell me..."

Are you sure you're not a Jedi master?

This HCR-188-C line looks REALLY GOOD as a next-generation solution to the current ozone depleters and greenhouse gas refrigerants. The C1 formula has already been approved as a substitute for R-134a, and looks to perform better at higher temperatures.


Adding to the sweetness, Mr. Maruya (and his trust) is in the approval process for the C2 formula. Designated as R-443a, it does its job in the R-22 range.

[jeff5may]

Award-Winning Product Development

In January 2013, after significant beta testing at customer sites across the US, Stirling Ultracold introduced the Model SU780U to fulfill a market demand for a large (27.5 cu.ft.) upright ultra-low freezer to replace conventional cascade freezers. Successful deployment of the SU780U and independent customer performance testing generated critical praise from biorepository and pharmaceutical experts worldwide.

In May 2013, Stirling Ultracold received the International Society for Biological and Environmental Repositories’ (ISBER’s) Outstanding New Product of the Year Award for its Model SU780U ultra-low temperature freezer. The award, given to one product annually, recognizes the company’s development and introduction of the world’s most energy efficient ultra-low temperature freezer, the Stirling Ultracold SU780U.

M100 free-piston stirling engine carries a 7 year warranty
Cools to -86 degC
Uses helium as refrigerant

[MEMPHIS91]

I love my R290 its cheap, easy to use, and lets you know if you have a leak (lol).
But in my recent experience, 80% R1270, and 20% R290 worked amazingly well. Though I saw slightly higher amp draw from the compressor my COP jump .7 from just using plan R290.

I have more data on this in the hot water heater build when I finally get the time to post again.