UK: Star Refrigeration has become the latest UK company to test the low GWP HFO refrigerant 1234ze in a chiller.
The Glasgow-based company has teamed up with Danfoss, manufacturer of the high efficency Turbocor compressor, and refrigerant developer Honeywell to develop and test the HFO 1234ze(E) refrigerant in one of Star's Indigochillers.



The chiller was comprehensively tested at Star's UK manufacturing facility 
in Glasgow, including operating in an ambient of 40 deg C on Star's 1500kW test rig. Turbocor engineers worked closely with Star during the testing and were able to verify and adjust their control software while the new Turbocor TG310 prototype compressor was in operation.



This was the first time that Danfoss Turbocor had access to the prototype 
compressor on a live air-cooled chiller to verify their theoretical
 calculations and lab tests. The adjustments helped to raise the efficiency 
of the chiller by a few percentage points.



Commenting on the tests, Star's group engineering director, Dr Andy Pearson said: 'Working with R-1234ze proved to be quite challenging. We found particularly good performance at part load in lower ambient, where the efficiency was up to
 20% better than the original predictions.



'Across the full range of load and ambient conditions performance
was generally better than predicted. The development included some tricky
 puzzles. Some of the materials used in joints and seals did not perform 
well, so we had to source special o-rings for some of the system components. 
We also learned that the lower gas density can cause increased pressure 
losses in some unexpected places, so care needs to be taken when assessing 
condensers, evaporators and control valves to make sure they are not going 
to cause excess pressure drop which would negatively affect the chiller
 efficiency.'



Now that tests are complete, the chiller has been installed at the Honeywell 
research site in Buffalo, New York, where the 1234ze refrigerant was 
originally developed. The chiller will operate on the base load for the 
lab's air-conditioning system, helping to keep the developers of the next 
generation of refrigerants comfortable at their work.