At the ASHRAE forum “High-Temperature Heat Pumps: Where Have All the Good Refrigerants Gone,” it was acknowledged that although U.S. use of HTHPs has died down, rising fuel prices could resurrect the market for these extremely efficient systems.

It could, that is, if there were refrigerants ready to replace R-11 and -114.

In Europe, researchers are looking into CO2 for use in high-temp applications. But in industry, “There is no suitable refrigerant to replace 11 or 114,” stated a forum attendee.


Propane (R-236fa) was mentioned as a potential candidate for replacing 114; 245fa could replace 11.

But “For the time being, these are not readily available to the market,” it was stated. “There won’t be an industry production of [the propane refrigerants] because the market is so small.”

There is a similar predicament for HCFC-124, which is used in a/c systems for foundry crane cabin enclosures, and which will be phased out in Europe in 2001.

“I think everyone came here looking for answers,” remarked an attendee.


In light of an absence of viable replacement refrigerants, the discussion turned on the potential of modifying the existing equipment using 11 and 114 to handle pressures found in CO2 systems.

For service water heating, output temperatures range from 120° to 140°F. On the source side, condensing water is about 90° (50° for chilled water).

Food processing systems need an output temperature that is constant; the input can fluctuate. So it could be a matter of changing the instrumentation, more so than the refrigerant.

Refrigeration system manufacturers are looking for a refrigerant that can handle high discharge temperatures. HFCs run lower discharge temperatures.

In addition, it was pointed out that compressor technology would need to be further developed.

There’s no doubt that reciprocating and centrifugal technology is highly efficient. However, the higher first cost, combined with refrigerant phaseouts and energy costs that have been lower, drove out the products.

“We’re trying to promote a technology when we don’t have a product to use,” stated an attendee. “What’s needed to get back to where we were?”

So, perhaps we need niche market manufacturers to provide the product — with a usable refrigerant.

Sidebar: R-114 talk on the show floor

Gib Gaeke, with Hudson Technologies, commented that “Most of the 114 we process goes to Lockheed if the price is low enough.”

Also, “There’s a lot of 114 in Canada that’s begging to get out.” Import restrictions and the costs associated with bringing it over are pretty much keeping it in Canada.

According to Alan Rorr with Refron, “Nobody’s returning 114.”

Similarly, “We’d like to get a lot of 502. People are holding on to it.”

It’s possible to use 141b for 11 in some applications, mentioned Eric Delhoume with Carlorie S.A., and 124 for 114. CO2, while still experimental, may be possible in a few years as a secondary refrigerant.