Often a chiller is business critical, however provided the required temperatures are being maintained it is assumed that the machine is healthy. This is often not the case and it is only a matter of time before expensive failures occur, which if they had been dealt with earlier could have been resolved as part of the normal maintenance regime.

A recent example was a data centre, which appeared to be operating under very high load. A survey undertaken by Excalibur using the Climacheck monitor showed that of the 12 refrigeration circuits 9 were short of refrigerant, further investigation showed that 6 circuits had less that 70% of the plated charge and of those, 2 circuits were under 40%.

Independent tests undertaken by BRECSU show that if refrigerant charge is reduced by 15% there is a corresponding 45% drop in capacity, it was clear why the chillers were having to work hard.