Brochure

BASIC SIZING GUIDELINES
The flow rate capacity of tankless water heaters depends on the
temperature difference between the desired output and incoming
water temperature. The flow rate comparison chart and table shown
here summarize the flow rate charts found in the specifications of
each model.
A. O. Smith water heaters are sized according to the peak flow rate
requirements, worst-case temperature-rise scenarios, and types of
applications. Once these factors have been determined, refer to
either the flow rate comparison here or the flow rate charts found
in each model’s specifications. Select the appropriate water heater
as well as the amount of water heaters required.
MATCH THE UNIT TO YOUR NEEDS
Application designers/engineers can decide whether to size for
full flow, expected flow, or utilize probability models such as
the modified “Hunter Curve.” For large scale applications such
as hotels, apartment complexes and large restaurants, Hunter
Curves are commonly used to estimate the peak flow rate
demand when given the total amount of fixture units within
an application. It is up to the application designer/engineer
to determine the amount of fixture units within any given
application.
110/U/C
Non-Condensing Units
Condensing Units
Commercial Units
310/U/C
240H
340H
540H/P
510/U/C
910
140H
2.5 Showers
2.5 Showers
3.5 Showers
3.5 Showers
4.5 Showers
7 Showers
5 Showers
3 Showers
2.5 Showers
2.5 Showers
2.5 Showers
2.5 Showers
1.5 Showers
1.5 Showers
4 Showers
3.5 Showers
(Assuming the set point temperature is 120˚F )
Cooler Climates
50°F Incoming Groundwater Temperature
Warmer Climates
70°F Incoming Groundwater Temperature
Capacity - Number of Shower Heads
CT-199
4.5 Showers
3 Showers
8