INTELLIGENT GREEN TECHNOLOGY
But they each also have issues . Propane and ammonia are highly flammable and ammonia is also toxic , while CO2 is simply not very efficient for cooling applications and requires a complicated , and expensive , technology . As a result , only a niche market exists for each option .
Which brings us to the man-made refrigerants . Some of them are emerging as potential replacements for R410A , L-41 , R32 , DR55 and DR5 .
All of these are still under development and are , again , not without issues . Chief among them is they are all flammable , although slightly , while current solutions are not flammable . But clearly it is preferred that the refrigerant coursing through your datacentre not be so flammable that it presents a fire hazard .
It may be some time before we see a suitable replacement for R410A on datacentre applications .
The news is brighter on the replacement for R134a . Here we have got three main refrigerants coming to the fore : R1234yf , R1234ze and some blends of R1234ze and R134a , one of those is defined XP10 . Of those , R1234yf is going to be used massively in the automotive industry and is consequently expensive and not widely available , while any blends between R1234yf and R134a are featured by not a really low global warming potential .
Overall , R1234ze seems to have the most support . It is only slightly flammable and fairly efficient , although not quite as strong in terms of cooling capacity as R134a . Given
GWP
Global warming potential is an index based on CO2 equivalent tons to measure the impact of a greenhouse gas on the atmosphere . Refrigerants commonly used on chillers have global warming potential values between 1,000 and 4,000 . New alternative refrigerants dramatically decrease such values . that , it works out to be about 30 % more expensive than R134a . Still , of the three , R1234ze is fairly far along in terms of development and appears to offer the best tradeoff in terms of price , performance , flammability and global warming potential .
Moving to a new component , such as one as critical as refrigerant , is certainly a challenge , however the good news is that it is possible to leverage R1234ze specific features in order to not just greenwash cooling , but also get the opportunity to improve machineries .
Another important opportunity which is offered by this new refrigerant is the application in warm areas of high water temperatures . A current limitation of high water temperature application is the maximim ambient conditions allowed by R410A or R134a when chillers are providing 18 , 20 ° C chilled water .
So , expect to see changes in how we cool our datacentres coming down the pike . It is clear that some changes will come sooner than others , but that change is coming .
Maurizio Frizziero is the current Global Product Line Manager for Air Economisers and Chillers at Schneider Electric
46 Issue 04 INTELLIGENT TECH CHANNELS