Can redundancy be designed into Off Peak Cooling systems?
Look at an example comparison of conventional cooling with two fifty-ton chillers for a 100-ton building and partial ice storage. The TES system for this example might be two 30-ton chillers and one Calmac 1320 ice tank. If only one chiller works on the conventional system, 50 tons of the 100-ton peak cooling load can be met. If only one chiller works on the partial ice storage system, 50-tons of the 100-ton peak cooling load can be met too. Thirty tons come from one chiller and 20 or maybe even 25 tons come from the ice generated at night by the operating chiller. The systems have similar capabilities should one machine be inoperable. The risk of a component down is the same for each system. Comparing like systems is very important for an economic evaluation. If the level of redundancy is similar for conventional cooling and TES, the value of partial ice storage can be proven. Lets examine a 100-ton building. A redundant conventional design is (2) 100-ton chillers. The partial storage
