Rise x 1 0 btu input gph x 8 25 x temp.
Water heater sizing formula.
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.
Establish peak demand measured in gallons per hour gph.
The formula goes like this.
Sizing storage and heat pump with tank water heaters.
H out heating capacity output btu h q flow rate gph ρ 8 34 density of water lbs gal dt temperature rise o f c p 1 0 specific heat of water btu lb o f input heating capacity.
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.
Rd total gallons of 120 f water required tw total number of washers 1 2 conversion factor 160 f to 140 f c2 diversity factor for 20 minute cycle c3 diversity factor for 30 minute cycle sr minimum storage requirement.
Smith pro size sizing program is a tool that can be used to estimate water heater requirements for many common applications.
After sizing a tankless water heater and evaluating your needs it may become clear that a tankless water.
Rise x 1 0 btu hr.
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.
Then evaluate tank water heaters on the same gph basis to determine how many gallons of storage are needed to meet this demand.
1 btu is equivalent to the amount of energy it takes to raise 1 lb of water by 1 f.
Once you have your total flow rate and the required temperature rise you can find the right size tankless water heater for your home.
Pro size is intended to assist in selecting water heaters or boilers that best meet the specific job requirements.
Various formulas for water heating calculations efficiency gph x 8 25 x temp.
Input heating capacity of a domestic hot water system.
Water heater sizing heating water is the second biggest energy expense in your home.
Btu is a measure of how much energy is needed to heat water.
Input specific heat btu output gph x 8 25 lbs gal.
Output heating capacity of a domestic hot water system.
The higher the btu the more water it is capable of heating.
To select the right state water heater for your home try our xpert product selector for personalized estimates of the performance and estimated energy cost.
Sizing tank water heaters.
While tankless water heaters do not run out of hot water if not sized correctly the flow rate of that water can be adversely impacted.
