At Energy Geeks we take great pride in the design and construction of our energy-efficient homes. Case in point, our recently completed home in Woonsocket, R.I. attained Tier 2 status in National Grid’s Residential New Construction (RNC) program. According to tests performed by a third-party HERS rating company, compliments of National Grid, this energy-sipping beauty of a home came in at 34.9% more efficient than their reference home.
One of the driving forces behind these impressive savings comes from the Air Source Heat Pump water heater used on this project. To learn more about these great performing appliances go to the following:
Heat Pump Water Heaters
A heat pump can not only be used to heat and cool your home, but also be used to heat water. To work, an air-source heat pump water heater pulls heat from the surrounding air and dumps it—at a higher temperature—into a tank to heat water.
A heat pump water heater looks like a tall cylinder with a small chamber on top and a larger one on the bottom. In the top chamber are a fan, a cylindrical compressor, and an evaporator that runs along the inside of the chamber. Jutting out from the exterior of the bottom chamber is a temperature and pressure relief valve. This valve has a tube called a hot water outlet attached to the top. Below the valve is the upper thermostat, a small square outside the cylinder that is attached to a curved tube inside the heater. Resistance elements run from the upper thermostat to the similarly shaped lower thermostat. Below the lower thermostat is a drain valve with a cold water inlet attached to the top. Inside the cylinder is an anode, a series of thin tubes running through the bottom chamber to a coiled tube called a condenser. Insulation runs along the inside of the cylinder.
Selecting a Heat Pump Water Heater
Heat pump water heater systems typically have higher initial costs than conventional storage water heaters. However, they have lower operating costs, which can offset their higher purchase and installation prices. You can purchase a heat pump water heating system with a built-in water storage tank and back-up resistance heating elements. You can also retrofit a heat pump to work with an existing conventional storage water heater. You can also install an air-source heat pump system that combines heating, cooling, and water heating. These combination systems pull their heat indoors from the outdoor air in the winter and from the indoor air in the summer. Because they remove heat from the air, any type of air-source heat pump system works more efficiently in a warm climate.
Before buying a heat pump water heating system, you also need to consider the following:
- Size and first hour rating.
- Fuel type and availability
- Energy efficiency (energy factor)
- Overall costs
Installation Considerations
Proper installation and maintenance of your heat pump water heating system can optimize its energy efficiency. Proper installation depends on many factors. such as fuel type, climate, local building code requirements and safety issues. Therefore, it’s best to have a qualified heating contractor install your heat pump. Heat pump water heaters require installation in locations that remain in the 40º–90ºF (4.4º–32.2ºC) range year-round and provide at least 1,000 cubic feet (28.3 cubic meters) of air space around the water heater. Cool exhaust air can be distributed to the room or outdoors. They should be installed in a space with excess heat, such as a furnace room because they will not operate efficiently in a cold space. They tend to cool the space where they are located.
