Water Heaters 101

If I thought long and hard about all of the things I take for granted, hot showers would certainly be among them. Even in the heat of summer, I religiously enjoy at least one hot shower a day. These hot showers wouldn’t be possible without an under-rated fixture of the modern home: the water heater.

You've probably got a tank hiding out in a closet somewhere, and I'm sure you're familiar with the basic premise. But there is actually quite a bit of variation when it comes to how we heat our water, from electric or gas to solar-powered or tankless. If you've just found out you need to replace an old heater, or are just curious, read on to learn more.

Storage Tank

These water heaters are by far the most common in the United States. Traditional heaters are designed to store 30-50 gallons of water in an insulated tank. These heaters can be fueled by oil, gas, or electricity. The biggest advantage in this traditional design is its ability to store heated water until needed. In recent years, smaller models with around 20 gallons of capacity have also become popular for smaller spaces or even to supplement larger heaters. However, these models have some drawbacks. The one most common is related to its shape and size -- some of these tanks can be up to six feet tall. Another common drawback is that this model is designed to heat a capacity of water and store that water – once all that water has been used, these water heaters need time to refill and reheat.

Tankless Water Heaters

If you’ve ever traveled outside of the country to places like Central and South America or Asia, chances are you’ve seen tankless water heaters, or on-demand heaters. You might notice them placed near a shower head, as a flat, rectangular box. These water heaters do not store water. Instead, it heats water as it passes through a series of coils in the unit. These heaters tend to be more energy-efficient than the storage tank variety and can be fueled either electrically or by fuel. The main disadvantage of tankless units is that they can only provide a limited flow of hot water. Another disadvantage is time. These heaters are controlled by an on-off switch. Therefore, these heaters do not store readily available water and take a little time to kick in. Lastly, many homeowners may find that the appearance of the unit may disrupt the layout of their bathrooms.

Fossil Fuels

As mentioned previously, water heaters are manufactured with different types of fuel sources that include electric, gas or propane, heating pump, and even solar power.

Electric tanks are the most popular and generally the most affordable. However, these heaters can be expensive to repair when heating elements burn out. Recently, many models of high-efficiency electric heaters have hit the market, drawing many homeowners back to electricity-based water heating due to the convenience and more reasonable energy costs.

Gas Tanks

These tend to be more popular in regions with an already established market for natural gas. These tanks are more expensive but generally heat water both faster and hotter than electric models. It goes without saying that these tanks are also slightly more dangerous. These tanks use flame to heat the water, and this has to be taken into account when installing and using them. They can be very cost-efficient, however, depending on the exact model and fuel costs in your area.

Heat Pumps

Heat pump water heaters are a variation on the traditional electric design that results in major boosts in energy efficiency. These heaters warm the water by using energy from the surrounding air through a process not unlike typical expansion-compression refrigeration. The tanks can be a bit larger than traditional electrics, and they are also more expensive. They do result in lower energy costs, however, with the heat pump process being about 2-3 times more efficient than a typical electric resistance element, and many have resistance elements to fall back on in case the demand for hot water exceeds its ability to supply it solely through the heat pump.

Solar Power

A relatively recent contender that has become popular with fans of green energy, these tanks use solar cells or panels that convert the sun’s light to energy that used to heat the tank. Though they are still more expensive than their traditional counterparts, the price of solar technologies is falling, and these heaters will result in immediate benefits on your power bills. After all, nearly a third of the average power bill in homes with traditional heaters is going to heating water, and a solar-powered water heater can reduce that expense by 80% or more.