[shahnawazhamid]

Hi,
how to calculate system volume (chilled water content) by knowing GPM and TMBH for a variable chilled water flow system.Please advice
thanks & regards
shahnawaz

[dulenz]

If you are designing primary/secondary system than you should have 3.5 l of water per kw of minimum installed capacity. That volume should be in the primary circuit. Your minimum installed capacity is the size of the smallest chiller divided by the number of compressors that chiller has.

For constant flow systems you look at the whole circuit not only primary

Actual figure of water quantity per kw depends from manufacturer to manufacturer. It is the best to check with your chiller supplier what they want because you can have issues with warranty later on if you do not have enough water.

Some manufacturers (Carrier) recommend that you should have 3.5l per installed capacity which in primary secondary systems usually means large buffer vessel.