Water Heating

Increase Water Heating System Efficiency

Although a hot-water system accounts for only about 4 percent of a building's total energy consumption (that figure is higher in buildings having a laundry or restaurant), increasing the system's energy efficiency is nonetheless worthwhile. The heater's energy efficiency can be raised; the storage tank, supply piping and recirculating piping can be insulated to reduce energy losses due to radiation, convection and conduction; water temperature guidelines can be strictly observed; and tenants can be encouraged to conserve. Energy savings can be achieved by placing water heaters close to usage points rather than installing one central generation tank and long runs of hot-water piping. To determine whether the installation of local units would be advantageous, analyze the building's hot water demand patterns. Next, estimate the existing system's total energy losses; then calculate the local units' potential savings. The energy saved is the sum of the reduced distribution losses and the increase in the average generation efficiency of local units, as compared to a central system.