ABSTRACT
As discussed in Section 3, storage capacity is influenced by building peak cooling load, maximum integrated daily cooling load and the operating mode selected. A typical ice-builder type unit using submerged pipe coils holds as much water as ice when fully charged. In a well-designed system, the average ice temperature typical ly is 6F below freezing, or 26F, for the conditions at full capacity. The absor ption capacity per pound of ice is determined by adding 3 Btu/lb (6F x the specific heat of ice, 0.48 Btu/lb, F) to the heat of fusion of ice, which is 144 Btu/lb for a total of 147 Btu/lb of ice. Since tank volume is approximately 50% water and 50% ice, the water from the melting of ice plus the residual water in the tank warms from 32F to the highest useful level (after passing through the cooling coil), adding another 1 Btu/lb per degree F. The available heat absorption capacity per pound of ice storage based on highest acceptable chilled water temperature can be estimated from Table 4-1.
