The OSU Sustainability Office is currently surveying campus to replace electric storage water heaters with heat pump water heaters (HPWHs) to cut down our energy usage. A few of the existing electric storage models use nearly 5000 kWh per year. The most efficient electric storage water heaters have an Energy Factor (EF) of 0.95 due to this technology’s physical limitations. Energy Factor is the ratio of useful energy output from the water heater to the total amount of energy delivered to the water heater. The higher the EF is, the more efficient the water heater. HPWHs have an Energy Factor of 2.0 or higher.
A HPWH takes heat from the air around it to raise the temperature of the water. To best utilize this process, a HPWH should be placed in a warm location. They are typically 60% more efficient and a warrantied for 10 years. Most of the water heaters around campus are located in warm closets or mechanical rooms. This makes the HPWH a perfect fit for campus.
For residential applications, a HPWH can save even more money. In a typical residential home, an electric water heater consumes the second highest amount of electricity. When selecting a HPWH however, make sure you select an Energy Star approved model. They are tested to meet energy efficient guidelines from the EPA and DOE.
A few of the existing locations on campus that we plan to replace include: Moreland, Shepard, Gladys Valley, and Rogers. If you are on campus and would like us to survey your water heaters for potential replacement please let us know. So far, we have installed a GE 50 gallon Heat Pump Electric Water Heater on campus that is already saving electricity.