Home Improvement : Plastic Water Heater Has Many Advantages

QUESTION: My old electric water heater is getting leaky and it doesn’t supply enough hot water for morning showers. What are the most efficient and durable electric water heaters made and what size should I get?

ANSWER: The cost of hot water for a family of four using an electric water heater can be as much as $400 a year. Even a small increase in overall efficiency (called energy factor) can result in a substantial saving on your utility bills.

The energy factor (EF) can range from about .80 to .96. For example, with an electric rate of 8.5 cents per kilowatt-hour, the saving in upgrading from an EF of .80 to an EF of .96 can be about $80 a year. Heavy foam tank wall insulation provides the highest EF.

One of the most durable and energy efficient, new electric water heater designs uses a heavily insulated all-plastic tank. Since plastic won’t rust, the water heater tank carries a lifetime no-leakage guarantee.

A durable plastic tank offers several other advantages. The internal shape of the tank can be designed to provide for optimum water circulation. It allows for more foam insulation at the tank top where the water is hottest. A smooth concave bottom allows the sediment to settle and flow out when you open the tank clean-out drain.

Also, an anode rod (used to reduce corrosion in a standard glass-lined steel tank) is not needed. With certain types of water, an anode rod can cause the hot water to have a peculiar odor.

When determining the size of water heater you need, the “first-hour rating” indicates how much hot water it can provide. This includes the volume of the hot water tank plus the amount of incoming cold water it can heat in one hour. A high-efficiency 52-gallon electric water heater can provide about 59 gallons of hot water for the first hour in the morning.

If you don’t have enough hot water in the morning, you can install a small point-of-use electric instantaneous tankless water heater in your bathroom. This heats the water as it is needed at the shower. Since it doesn’t have to keep a large tank of water hot, it is very efficient.

By installing a small instantaneous water heater, you may be able to lower the water temperature in your regular water heater. This further reduces the heat loss from your water heater tank.

You can write to me at the address below for Utility Bills Update No. 417 listing addresses and telephone numbers of manufacturers of small electric instantaneous and high-efficiency standard tank-type water heaters (including the new all-plastic model), first-hour ratings and energy factors, and a work sheet to determine the size of water heater you need. Please include $1.50 and a self-addressed business-size envelope.

Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.