Hot Water Heater Sizes

Sizing storage and heat pump with tank water heaters.

Hot water heater sizes.

Consequently these are the two most frequently installed sizes. But if you only need a loose estimate of what size you need versus an exact calculation follow these guidelines. However every family has different water demand requirements. You can estimate the necessary tank capacity in gallons based on the number of people in the house.

1 2 fixtures at once you ll need at least 3 5 gpm. For 1 to 2 people. The good news is that just by following a few guidelines you can find the perfect size water heater. 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.

1 or 2 people 23 to 36 gallons 2 to 4 people 36 to 46 gallons 3 to 5 people 46 to 56 gallons 5 or more people over 56 gallons add 10 gallons per additional person. Hot water will be delivered faster when the water heater is closer to the fixture because the length of piping in between the two is shorter. The rheem professional prestige high efficiency tankless gas water heater 9 5 gpm has an overall height of 27 5 69 9 cm width of 18 5 47 cm and depth of 9 75 24 8 cm. The rheem professional prestige high efficiency tankless gas water heater 9 5 gpm weighs 82 lb 37 2 kg and has a maximum flow rate of 9 5 gallons per minute.

The temperature of the piping between the water heater and the location of the water fixture is another factor that may impact hot water delivery. 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. Smith pro size sizing program is a tool that can be used to estimate water heater requirements for many common applications. Pro size is intended to assist in selecting water heaters or boilers that best meet the specific job requirements.

Climate weather seasonal changes and the. If your plan to use 5 or more fixtures at once you may need multiple tankless units in sequence. Well to get an accurate answer you d have to calculate out how much hot water you typically use during your busiest hot water using hour. What size water heater do i need.

30 40 gallons for 2 to 3 people. Determine the home s fhr or first hour rating. That s the measure of how much hot water the heater will deliver during a busy hour such as first thing in the morning. 3 4 fixtures at once you ll need at least 7 gpm.