Refrigerant choice in HVAC chillers

Dave Richards: “Chiller manufacturers are relocating immediately in the suitable route and now have a quantity of reduced GWP selections obtainable to them”

In the gentle of the worldwide phase-down of superior GWP refrigerants, Dave Richards, Uk head of profits at refrigerant supplier Climalife, seems at the different possibilities readily available for HVAC chillers. 

There are a lot of various types of chiller, even so in conditions of refrigerant they can be break up into a few sorts: reduced, medium and significant force. 

Though legislation is driving and influencing the alternative of refrigerant, from a European point of view the F-fuel legislation has not applied any bans for chiller purposes as they have not applied refrigerant with a GWP >2500. On the other hand, the European F-gas section down and very similar reductions less than the worldwide Kigali Modification will have a profound effect on the alternative of refrigerant used in new chillers in the subsequent couple of many years. 

Small strain refrigerant chillers

Traditionally these originally used the CFC R11 which was changed by the B1 safety class HCFC R123, but legislation intended this variety of chiller declined in use, even though non-ozone depleting R245fa was used in some equipment. Far more not too long ago these minimal pressure chillers have commenced to make a comeback with the use of really small GWP R1233zd (GWP 4.5), an A1 safety course one element refrigerant for use in new equipment and R514A (GWP 7), an azeotropic B1 basic safety class refrigerant mix. R514A can be utilized in both of those new machines or as a non-ozone-depleting retrofit in current R123 chillers. 

Mitsubishi Heavy Industries was an early adopter of R1233zd in its ETI-Z collection chiller

Medium stress chillers

This sector has been dominated by R134a because it was launched back in the early 1990s as a alternative for the CFC R12. R134a has been utilised extensively in chiller programs, predominantly in the larger conclusion of the chiller industry with tools manufacturers however featuring a assortment of tools with R134a as the major solution.

Whilst R134a has a GWP of 1430 and isn’t subject to any existing bans in the EU, there are currently reduce GWP solutions commonly readily available. Several of the primary makers of chillers produce a array of air-cooled, drinking water-cooled and distant condenser chillers that have a wide range of cooling capacities from 20kW up to 2MW most now have reduce GWP alternatives obtainable.

R513A, a non-flammable refrigerant with a GWP of 631, has been promptly adopted by a range of companies and can easily be made use of for retrofitting R134a techniques, with incredibly very similar cooling capability and functionality.

R1234ze, a single part HFO with a GWP of 7, has been available considering that 2012 for use in new products. Though it is suitable for applications where by R134a was beforehand employed, it is not appropriate as a retrofit owing to its decreased cooling capacity. Also, although it presents a far better strength efficiency than R134a, it is classed as A2L underneath the ASHRAE 34 and ISO 817 requirements. 

R515B was new mix introduced to the market place in 2020. Predominantly R1234ze(E), with the addition of just a tiny amount of money (8.9%) of R227ea, it has been described as an A1 (non-flammable) version of R1234ze with virtually similar overall performance characteristics. It has a GWP of 293 and is for use in new machines. Once more, it is not a retrofit alternative for R134a as the ability variation is also great for most purposes.

R515B is available by Carrier in its Aquaforce drinking water-cooled chillers and heat pumps

R1234yf is already in widespread use in the automotive sector and is one more solitary part HFO with a really reduced GWP (4) and as a result can be regarded as a extensive-time period sustainable refrigerant.

Some chiller possibilities are readily available for use with R1234yf which in conditions of general performance is really close to R134a. It is an A2L decrease flammability refrigerant preferably suited for use in new devices.

Beneath the Stress Devices Directive (PED) R1234yf is in fluid safety team 1. While retrofitting from R134a may possibly be achievable, any adjustments to the gear PED classification require to be comprehensively deemed as well as cost sizing constraints from EN 378 and a appropriate hazard evaluation will be essential, which will take into account any probability of the formation of flammable zones.

Neither R1234ze nor R1234yf come under the F-gas period down this means they provide an unrestricted resolution as the phase down tightens on increased GWP refrigerants in the years in advance.

Large strain chillers

Over the last 15 yrs the use of R410A in chillers has developed considerably, however with a GWP of 2088, it is not sustainable in new machines as the F-gas stage down actions effects. The foremost contenders are at present R454B and R32, all of which are A2L classified refrigerants. Even though some are wanting at the alternatives of the medium tension refrigerants described previously mentioned.

R454B with a GWP of 466 seems to be at present major the way with a selection of producers as it is a near match to R410A in phrases of working overall performance and qualities and has the least expensive GWP. We are observing an escalating variety of chiller producers creating this option offered to the current market.

Trane’s Sintesis Gain CGAF air cooled chillers is a person of a variety now out there with decreased GWP refrigerant R454B

R32 with a GWP of 675 has observed swift development as a alternative for R410A in break up AC programs and we are now starting to see some chillers coming to market with R32. The qualities of R32 has meant that a lot more gear redesign may possibly be demanded by equipment producers.

Other refrigerants worthy of a mention are R290 (propane) and R717 (ammonia). Some brands are giving HVAC methods utilizing R290 but the demands for making use of an A3 very flammable refrigerant can be a minimal more restrictive than employing a decreased or non flammable choice.

While EN 378 does not limit charge sizes if the system is in the open up air, acceptable hazard assessment getting into account the prospective formation of flammable zones is necessary and possible to be substantially a lot more restrictive than employing a decrease flammability choice.

The use of R717 is common in industrial chillers where by the toxicity and flammability can be far more very easily managed but is almost never noticed for basic HVAC purposes.

The uptake of flammable refrigerant in some nations is affected by creating regulations, but chillers are usually roof-best-mounted, building the use of the reduced GWP A2L refrigerants a minor simpler.

Seeking to the future

Changing the refrigerant utilised in chillers is not always a fast system as it should fulfill a range of standards, such as operating at the wanted tension and temperature, provide the accurate degrees of cooling and be much more electricity successful than its predecessors. 

New chillers mounted now require to be practical around their life time, which can be 20 to 30 several years, so it’s vital to decide on a chiller that makes use of a sustainable refrigerant. The chiller makers are transferring rapidly in the ideal path and previously have a range of reduced GWP selections readily available to them to be in a position to meet the limits F-gasoline legislation results in. There are a lot of primary suppliers that have unveiled or are releasing tools that is large undertaking, electrical power efficient and price tag successful with the use of lower GWP refrigerants. These provide a very long-phrase option in buy to long term evidence a structures air conditioning procedure and to consider techniques in direction of tackling the urgent problem of climate improve.

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