Basic Sizing Guidelines

The flow rate capacity of Thermomate tankless water heaters is determined by the temperature difference between the desired output and the incoming water temperature. The flow rate comparison chart and table below summarize the flow rate charts found in the specifications of each model.

Thermomate water heaters should be sized based on peak flow rate requirements, extreme temperature-rise scenarios, and the specific applications they will serve. Once these factors are identified, refer to the flow rate comparison here or the flow rate chart in each model’s specifications. Select the appropriate water heater model and determine the number of units required.

Application designers and engineers can choose to size for full flow, expected flow, or use probability models such as the modified "Hunter Curve." For large-scale applications like hotels, apartment complexes, and large restaurants, Hunter Curves are commonly employed to estimate peak flow rate demand based on the total number of fixture units in the application. It is the responsibility of the application designer or engineer to determine the number of fixture units within any given application.


water flow | Thermomate