Heating water to take showers and wash dishes and clothes accounts for a big chunk of most homeowners’ utility bills — 25 to 30 percent. You might live with that expense for many years, but eventually your water tank will give out, and you’ll need to consider a replacement. This is an ideal time to assess whether energy-efficient tankless water heating is the way to go.As the name implies, a tankless water heater — sometimes called a demand water heater — channels cold water through a gas burner or an electric element. It supplies water as it’s needed. Therefore, a tankless system doesn’t require storing any water and keeping it hot, which means you’re not wasting energy. But even though a tankless system isn’t storing hot water, it can deliver it immediately.

While a tankless system is responsive and energy efficient, it’s not necessarily for every situation and every family. A tankless unit has limited capacity, and you might require more than one unit if your family tends to use a lot of hot water at the same time — for example if one person regularly showers while another family member is washing the clothes. To determine if you will need more than one unit, you and your contractor will have to add up the number of locations where you will be running water at the same time and calculate the flow rate, or number of gallons per minute that you will need.

You will also need to compute temperature rise. This involves subtracting the incoming water temperature from the desired output temperature. So if your incoming temperature is 60 degrees, and you want your water heated to 120 degrees, you will need a tankless heater that produces a temperature rise of 60 degrees.

Sizing a tankless water heater requires the advice of experts, like those at All Year Heating, Air & Solar. Call us so that we can guide you to the best and most economical water heater for your home and needs. We serve homeowners in the Sacramento area.

Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems).  For more information about other HVAC topics, download our free Home Comfort Resource guide.