Energy Asset Score Inputs for Water Heaters
Name – Default component text and counters are automatically added. This entry may be edited to include other descriptive or identifying text.
Fuel Type – The type of fuel used to heat water. Pull-down menu selections: Electricity or Gas.
Heat Pump Water Heater – Check box: Select if a heat pump water heater is present. Heat pump water heaters pull heat from the surrounding air to heat water stored in the water heater tank. They may be two to three times more energy efficient than conventional electric resistance water heaters.
Distribution Type – Pull-down menu selections:
Distributed – The hot water is distributed without being recirculated (see Hot Water Distribution Types figure.)
Looped – The hot water pipe is installed in a loop throughout the building, and hot water is constantly circulated through this loop by a circulation pump. In this distribution system the hot water reaches the valve in a fraction of a second. (See Hot Water Distribution Types figure.)
Water heater efficiency – Energy efficiency of storage, demand, and heat pump water heaters is determined by energy factor, which indicates the overall efficiency of the water heater and is based on the amount of hot water produced per unit of fuel consumed over a typical day. This includes recovery efficiency, standby losses, and cycling losses.
Note: The heater thermal efficiency is the thermal conversion efficiency from fuel energy to heat energy for the heater element or burner. This is not the same as the overall efficiency of the water heater.
Tank volume – Volume of the storage tank in gallons.
Tank insulation thickness. – Thickness of insulating material used in inches.
Tank insulation R-value – Measure of thermal resistance: the reciprocal of the time rate of heat flow through a unit area induced by a unit temperature difference between two defined surfaces of material or construction under steady-state conditions. R-value is in units of ft2*ft°F*h/Btu.
Use of Low Flow Faucets – Check box: Menu item available by clicking on a building block after assigning a water heater. Select if low-flow fixtures such as showerheads with flow restrictors, high-efficiency low-flow faucet and aerators, and auto-flush and ultra-low-flow toilets are installed and in use. Significant water and energy savings may result through the use of low-flow fixtures and equipment.
Hot Water Distribution Types Figure: