You’ve sealed up your home, and tuned up your HVAC systems for the upcoming heating season, right? But don’t forget about saving money with your water heating system. Better yet, replace your old storage-tank water heater with a more efficient tankless water heater, and you could save up to 50 percent on your water heating costs.
Tankless water heaters
Tankless water heating systems may be compared to a light switch. You only consume energy when the light switch is turned on. Tankless water heaters heat water instantaneously with an electric or gas-heated element, and shut off when the tap or appliance is turned off.
In contrast, storage-tank water heaters heat water to temperature, store it, and must reheat the water over and over to maintain temperature, whether or not hot water is being used. This is standby heat loss, and may account for more than half of water heating costs.
Sizing up for savings
To maximize efficiency, your tankless water heater must be sized specific to your household’s hot-water needs. The two primary elements for designing an efficient system are temperature rise and flow rate.
- Temperature rise is how much inflowing water needs to be heated to reach the set-point temperature. If the inflowing water temperature in your home is 67 degrees, and your desired hot-water temperature is 120 degrees, the temperature rise is 53 degrees.
- Flow rate will need to be calculated for each outlet and appliance to get your total household flow rate, and then matched to the right size tankless unit(s) per your design. The flow rate of an outlet or appliance is the amount of water, in gallons per minute (gpm), that it provides. Your household’s flow rate is the sum of the maximum outlets and appliances in use at any given time.
Small, medium or large?
Tankless water heaters are available in single point-of-use units, medium point-of-use units, and large whole-house units. By mixing and matching the size and models to your hot-water demand, you will achieve greater energy efficiency gains.
For more information about tankless water heaters, please contact us at Mowery Heating, Air Conditioning and Plumbing in the greater Indianapolis area.
Our goal is to help educate our customers in Brownsburg, Indiana and surrounding areas about energy and home comfort issues (specific to HVAC systems).