Hot Water

by Tim Gould

Hot water, like heat, is a necessity. Over the course of one year, the average household uses about 230 therms of natural gas or 3,500 kilowatt-hours of electricity to heat water, though there are other fuels such as propane and oil. (This is a home with two adults and two children.) At current rates of $1.80 per therm and $.018 per kilowatt hour, this energy use converts to $414 and $630 per year respectively. Of course, hot water usage varies considerably depending on a number of factors including household size, age of inhabitants, work schedule, and water heating capacity among others.

When it comes to conserving energy and saving money, hot water is an area in which significant savings can be realized. Water heaters use energy in three ways: demand, standby, and distribution.

Decreasing demand by reducing the volume of hot water used is fairly simple: Take shorter showers, install low flow (2.5 gallons per minute) shower heads, and use faucet aerators at sinks. These are no cost or low cost approaches that work. They save not only on the cost to heat water, but the cost of water itself.

Reduce standby heat loss by lowering the hot water storage temperature to a range of 120 to 126 degrees. Not only does this save energy and thus money, it also prevents accidental scalding by water that is too hot.

Distribution losses can be reduced by adding insulation around pipes. Also, an insulation blanket wrapped around an old water heating tank can save up to 10% of total heating costs alone. However, if your tank has 1.5 inches or more of foam insulation or the label says R-10 or more, adding a tank wrap will not help much.

When it comes time to replacing your hot water heater, take your time to evaluate the best options. Typically, people replace them when they fail in a hurried fashion and don't even consider efficiency. High efficiency water heaters typically have efficient burners, electronic pilots, and a high level of insulation. Try to get a water heater with the highest Energy Factor (EF) possible. If you have to continue heating water with electricity, consider adding a solar hot water system. If you have to replace your boiler, an indirect-fired hot water heater is more efficient than tankless coils and stand alone hot water units.

Don't take your hot water for granted or ignore potential money-saving improvements. It's a necessity that usually can be made more energy efficient.

© 2008 Tim Gould. All rights reserved.