Tankless Water Heater Load Calculation

Since tankless water heaters supply endless hot water you don t have to worry about capacity but instead think in terms of water flow rate.

Tankless water heater load calculation.

Enter only those fixtures determined to be peak demand. Tankless water heater efficiency is determined by the water flow rates inside your home. Affect the peak demand calculation in section c. This hvac calculator is the closest estimate to the actual manual j calculation done by hvac pros.

Rinnai strongly suggests that you only purchase our products from rinnai independent dealers and that you have the products installed only by licensed professionals who have attended a rinnai installation training class licensed professionals who have attended a rinnai installation training class. For new dwellings the service load should be calculated using nec 220 82. Smith pro size sizing program is a tool that can be used to estimate water heater requirements for many common applications. For existing dwellings the service load should be calculated using nec 220 83.

A low flow shower head may use 1 5 gallons of hot water per minute or gpm as it is called. Most tankless units can provide up to 3 5 gallons of heated water per minute. Range in size from 2 5 to 19 gallons. Gallons per minute gpm is the key when it comes to sizing tankless water heaters.

Pro size is intended to assist in selecting water heaters or boilers that best meet the specific job requirements. A sink may run. Hot water demand sizing in the fbc is by water supply fixture units wsfu. Looking to purchase a new tankless water heater but having trouble figuring out what size or model you need.

The tankless unit installed must supply the peak demand identified in this section. The heat load estimate is based on your climate region total square footage number of rooms or zones you want ceiling height insulation type number of windows and doors. Small storage water heaters tank type. Instantaneous water heaters tankless type.

Use our handy calculator to determine your needed flow rate and temperature rise then find models that match your needs. This hvac load calculator quickly estimates the size of your heating and cooling system in btu s. Tiny point of use pou electric storage water heaters with capacities ranging from 8 to 32 liters 2 to 6 gallons.