There are more options now than ever before when choosing a water heater that saves on energy. It’s worthwhile to carefully consider this purchase since hot water uses an estimated 30 percent of the total energy budget of the average household.
There are four basic types you can choose from. This guide will walk you through the pros and cons of each.
Conventional Storage Water Heaters
Storage tank water heaters are the most common in homes and may be what you’re most familiar with. They work by holding a large amount of water — up to 80 gallons – in an insulated tank and keeps the temperature at a constant hot temperature. The upfront costs of a conventional water heater is going to be substantially lower than the higher-efficiency alternatives, but the operating costs over several years will also be higher.
If you decide on a storage water heater, consider the following:
1. Size. Estimate how much hot water your family or business will use each day and buy the appropriately sized tank. Resist the temptation to over-buy. An over-sized tank will eat up energy sitting unused in the basement.
2. Energy Rating. Buy a water heater with a solid “first hour energy” rating. This is printed on the outside of the water tank and tells you how much energy the unit uses in the first hour of heating water. This is the most important rating you should pay attention to.
3. Energy source. An electric water heater will cost the most over time unless you hook it up to a solar source. Also, electric models are not as likely to be energy star approved. Natural gas is the cheapest and most efficient, followed by propane.
Tankless Water Heaters
A tankless water heat works by heating water on-demand instead of holding hot water in a tank. They are much more energy efficient than tank heaters, much smaller in size, but will be slightly more inconvenient in that there is usually a longer delay in getting hot water through a faucet. That said, once the unit starts churning out hot water, the supply is theoretically “endless.” On the downside, the temperature can fluctuate, sometimes severely depending on the model.
Lastly, tankless water heaters are going to cost more. On average, they run about twice the cost of the conventional tank heaters.
If you decide on a tankless water heater, consider the following:
1. Number. The standard tankless water heat can deliver 2-5 gallons per minute. If you have a large household or want to run several appliances and showers at the same time, you might have to buy more than one heater.
2. Energy source. Most tankless heaters will use gas, but there are electric models on the market as well. Needless to say, electric will cost more over time to run.
3. Your water. Hard water can be, well, hard on tankless heaters. Many manufacturers recommend getting the unit serviced once a year to prevent mineral build-ups from constricting your water flow.
Heat Pump Water Heaters
Heat pump water heaters work by transferring heat from one location to another rather than generating heat in a direct manner. Think if it like the opposite of how a refrigerator works.
The benefit of a heat pump is that they can be several times more efficient than conventional electric water heaters. And if you don’t have the option of using natural gas, this is by far the most efficient method of heating water.
Unfortunately, they are not cheap. The average model will run you upwards of $1000.
Solar Water Heaters
Solar water heaters use energy from the sun to heat water. There are models that use the direct heat from the sun’s rays to heat the water, usually on a rooftop, and then transfer that water to a tank to retain the heat until use. The other type of solar water heater uses a standard electric storage tank that runs off of solar panels.
Passive solar water heaters are typically pretty cheap to set up. The internet is full of DIY instructions on building your own. There are also plenty of kits available. The problems with passive solar water heaters are many, though. If the sun is not out, or it is cold, you’re out of luck. Also, the piping and plastic components on the roof can easily be damaged.
Solar panels are going to give you a more consistent result as power can be stored in batteries during cloudy days and at night.
Solar may be a good choice if you live in a area with abundant sun. And, you may qualify for a solar rebate. Check out our page on solar hot water rebates.
