Hello All, I have a question for heat exchange calculation and hope someone can help. I would like to recover the "cooling energy" from a ice melting pool for air-conditioning for a small office. I plan to install three fan coil units with 800CFM for the office with closed loop water pipe to circulate water from fan coil units to the cooling coil immersed in the ice melting water tank and then back to fan coil units. Hence, heat from the office will transfer to the ice melting water. Ice melting tank effective size : 4m x 2.2m x 1m(H) Ice melting water temperature : 3 ~ 5*C as measured Cooling coil : OD : 9.52mm OD; Length : 32.4m ; Material : copper Fan coil unit : each cooling capacity 7.92kW (assume water in at 7*C and leave at 12.5*C) What is the water circulating flow rate for the above system ? How long will the ice water support for the system (as the water temperature will rise up) ? Ice will be refilled for every 2 to 3 hours and cannot support air-conditioning at 7*C. Any assumption can be made. I only need rough estimation for reference. I have a normal air-conditioning system for the office as backup. This project is for environmental education purpose. Thanks !!