Water Heating and Energy Use
Water heating can be the third largest energy expense in your home, after heating and cooling. It can account for 15-25% of your utility bill. It’s not hard to see why. A family of four, each taking a 5-minute shower every day using inefficient showerheads, can use 700 gallons of water in one week. This is enough for a three year supply of drinking water for one person. There are several ways to cut down the amount you spend on heating water. Some ways include insulating your water heater and pipes, reducing the amount of hot water used, and turning down the thermostat on your water heater.
Water Heater Size
You need a water heater large enough to provide hot water during the household’s busiest times of the day. Consider the size of your family. A home with two adults could use up to 30 gallons of hot water in an hour, whereas a family of six may use 70 gallons in an hour of peak use. A water heater that is too small won’t keep up with your family’s hot water demands. However, a water heater that is too large will increase the standby losses (the amount of heat the water heater loses as it stands waiting to be used). This can vary by model. In addition, evaluate the need for an on-demand water heater. When the current water heater location is a long distance from the source of hot water use, consider an on-demand water heater located at that point of use.
Water Heater Location
If building a new home, try to locate the water heater close to high hot water use areas such as bathrooms, the laundry, and the kitchen. This will mean a shorter pipe “run” with less loss of heat through pipe walls and hotter water arriving sooner at the tap.
Maintaining Your Existing Water Heater
There are a few simple things you can do to improve the efficiency of your existing water heater. First, you should flush it out quarterly, semi-annually, or annually depending on the water hardness. This will reduce the build up of debris at the bottom of the heater that can reduce heat transfer and shorten the life of the water heater. Next, you can install pipe insulation on the inlet and outlet pipes to reduce standby losses. Lastly, you can insulate the tank, but be careful not to get too close to the vent pipe, restrict combustion air supply, or cover any controls.
Finding Energy Efficient Water Heaters
There are many ways to heat water. If you are in the market for a new water heater, first check the U.S. Department of Energy’s (DOE) Web site for information on energy efficiency, fuel types, new technologies, and availability. The DOE also has more information about Sizing a Water Heater. You might also check with your utility company, as they may offer rebates or incentives for certain types of energy efficient water heaters. Keep in mind that your choice of water heater and its fuel source will depend, in part, on where you live and the type and size of space available.
When shopping, read the EnergyGuide label, and look for the ENERGY STAR® symbol. Read more about ENERGY STAR products and water heaters.
When shopping for an energy efficient water heater, keep in mind your hot water needs. Also, don’t forget to take into account water conservation measures, like installing low-flow showerheads.
