DX is a reliable option but is not efficient for a baseload of approximately 1200 tons. A backup DX of that size is also very expensive and adds inefficiency due to the pressure drop across the DX coil which is normally not being used.
I found one ice storage application for a similar...
I have put tanks on the outlet of a chiller before but generally that is to keep the chiller from short cycling. If the amount of water in the system piping and coils is too small, the chiller will load and unload rapidly.
A simple tank on the outlet of the chiller will not protect the load...
I have installed large thermocline type chilled water storage tanks for energy cost reduction. The tanks I installed were several million gallons each and were 30 to 40 feet tall.
I am interested in applying a much smaller storage tank that would provide a short span backup of a critical load...
