customer has a small 12kw waterchiller they want to hook onto there 6000liter uninstalled plastic buffer tank, I dont have any flow rates but ive been trying to work out how long it would take to pull down from 20deg to 7degC tank only no other heatload - doesnt have to be accurate just a ruff idea but I am struggling to find a method, can anyboy help out or point me in the right direction

thanks