Water Chiller: What are the Trends in Refrigerants?

Most wine, beer and milk are made by a process that uses a water chiller. It is essential to take away the heat produced by mixing, cooking and pasteurization. Chilling systems are also indispensable in the medical industry. In particular, magnetic resonance imaging uses water chillers to take away the heat generated by the equipment. The air conditioner in most shopping centers and offices is also provided by a chiller located outside of the building. Finally, chillers are also used in ice-skating and curling facilities.

Clearly then, chillers play an important role in industrial and commercial activities. The applications are quite varied and consequently require different types of chillers. This affects some of the choices in the design stage, such as the size, the compressor and the refrigerant. Regarding the latter aspect, the refrigerants currently used in low-medium capacity chillers are R-410A and R-407C, whereas R-134a and R-123 are the predominant refrigerants in larger applications. However, the phase-down of high GWP refrigerants and the accelerated increase in prices of HFCs are forcing manufacturers to look for alternative solutions.

The objective of this phase-down in different countries is the same, however the actual rules differ. The aim of this post is to analyse which refrigerants are allowed for glycol water chiller in the European Union, the United States, Japan, China and Canada, and to thus try and predict what the trends will be in the coming years. This is a very important issue not only in relation to the variety of applications, but also for the HVAC cooling system market: of the total of 4.687 billion euros invested on the European market in HVAC in 2016, 46.3% was accounted for by chillers (Eurovent Market Intelligence data).

Chillers fall within the category of “stationary refrigeration equipment”, according to the F-gas classification. Therefore, refrigerants with a GWP higher than 2500 will be banned starting from 2020. This means that the most commonly-used refrigerants nowadays will still be accepted:

● R-410A, R-407C and R-134a 

However, the F-gas regulation also introduced regular leak checking, initially depending on the HFC mass in a circuit, and from 2014 depending on the number of tonnes of CO2 equivalent of HFCs. Thus, the higher the refrigerant’s GWP, the more frequently leak checking needs to be performed. Chillers as an application are especially affected by this part of the regulation, as they involve high refrigerant charges. For example, when using R-410A, R-407C and R-134a, leak checking is necessary for charges higher than 2.4, 2.8 and 3.5 kg, respectively. The increase in prices of high-GWP refrigerants is another factor that is pushing manufacturers to choose other alternatives. In the case of water cooled chiller to be sold on the European market, alternatives with a lower GWP are:

Chillers, according to the SNAP regulation, can be classified by compressor type, including centrifugal, reciprocating, scroll, screw, and rotary. Chillers used to cool industrial processes are included under the category of “industrial process refrigeration”. Accepted refrigerants for this application are:

The “Act on Rational Use & Proper Management of Fluorocarbons” considers two categories for air conditioning applications: room and commercial. In the first case, the GWP limit will be 750 from 2018; in the second case, 750 from 2020. Chillers may be commercial or non-commercial, but we assume that the limit for air-conditioning is 750 for all applications, as no other information has been specified. This means that R-410A and R-407C will not be accepted. The alternatives, taking into account flammability and toxicity regulations, are therefore:

● Ammonia

● R-450A, R-513A

There is a wide range of refrigerants that are suitable for different sizes of chillers. For mini chiller or medium chiller, typically dominated by R-410A and R-407C, the refrigerants accepted in the five countries analysed (except in the United States) are hydrocarbons, R-32, R-454B and R-452B. For larger capacities, refrigerants suitable for medium temperature applications, such as R-450A, R-513A, R-1234yf and R-1234ze(E)could be alternatives (except for R-1234yf in the United States), as well as hydrocarbons (except in the United States) and ammonia. R-1233zd(E) and R-1336mzz(Z) are accepted worldwide for higher capacity chillers (centrifugal), indeed their operating range makes them suitable for chillers that currently use R-123. 

It should be noted that not all the refrigerants listed here can be used for retrofit replacement on units designed for the current refrigerant. In particular, there is no replacement for R-410A without modifying the equipment, which is creating quite some concern. In the United States the situation is even more critical, as the list of alternatives for scroll chillers (where typically R-410A is used) is very limited.