What Size Tankless Water Heater Do I Need Calculator

The first factor in choosing a tankless water heater is calculating the size of your hot water heater.

What size tankless water heater do i need calculator. The first hour rating is the number of gallons of hot water the heater can supply per hour starting with a tank full of hot water. Rheem tankless electric water heaters make it easy to enjoy instantaneous continuous hot water space saving design and significant energy cost savings. Therefore to size a demand water heater you need to determine the flow rate and the temperature rise you ll need for its application whole house or a remote application such as just a bathroom in your home. How to size a tankless water heater.

To properly size a storage water heater for your home including a heat pump water heater with a tank use the water heater s first hour rating. If you want to upgrade your water heater size from 40 or 50 gallons storage water heater or replace it you won t necessarily need a big tankless water heater. Tankless water heaters do not store hot water. Instead they heat it as it s needed.

Flow rate is the key spec when sizing a tankless water heater o brian says. Once you have your total flow rate and the required temperature rise you can find the right size tankless water heater for your home. The right size is a tankless water heater that can heat enough gallons of water to a specific temperature per minute to keep up with the demand. Choose the right tankless electric water heater for you.

Below we ve highlighted what size water heater you would need in our example of 6 5 gpm at a 63 f temperature rise. Simply locate the appropriate water heater sizes on ecomfort using your information. Tankless water heaters are rated by the maximum temperature rise possible at a given flow rate. Sizing storage and heat pump with tank water heaters.

Just follow the three simple steps below to choose the right model and size you need. If you do the math for 50 temperature rise you need approximately 25 000 btu s per hour per gpm of water required which doesn t take heater efficiency into account but gives a good idea of the size of high efficiency heater needed. Electric units have measurements in the 10 inch high to 7 inch wide range while gas fired. Tankless water heaters are much smaller than units with a storage tank allowing them to be wall mounted.