Commercial Water Heaters

Boiler Kansas City Missouri These two commercial water heaters powered

Energy Efficiency requirements for 2015

A commercial water heater is often referred to as a boiler and is very different than  residential water heaters. Any water heater over 55 gallons is usually considered to be a commercial unit and has to comply with a higher efficiency rating. In April of 2015, all gas water heaters over 55 gallons will be required to have a minimum of .76 EF.

The new efficiency requirements will affect all types of water heaters but commercial water heaters will be impacted the most. In order to meet the efficiency requirements of the new boiler standards it may be necessary to install an intake and an exhaust. These units also require a power source in order to operate and often include an automatic pilot.


Commercial water heater sizing


AO Smith Commercial Water Heater Calculator

Bradford White Commercial Water Heater Calculator

State Select Commercial Water Heater Calculator


There are several commercial water heater manufacturers that have water heater sizingsoftware to help you choose the right water heater for your application. There are so many factors that go into restaurants and apartment buildings you really don’t want to undersize the unit.


In order to size a commercial water heater you need to determine the gallons per hour that will be used. A typical residential 40,000 btu, 40 gallon water heater will produce around 80 gallons per hour. The efficiency requirements for tanks over 55 gallons will be .76 Energy Factor, tanks under 55 will only require .62 EF.

In order to determine your usage rate of gallons per hour the following guide can be used.

Fixture                             Gallons per hour

Floor Sink                           15

Utensil Sink                        24

Bar Sink                               6

Food Prep Sink                  5

Pre Rinse units                 45

Washer                                45-60

Dishwashers                     5-8 Gallons Per Minute


Kansas City is considered a cold temperature climate in which we usually need the temperature to rise about 70 degrees. You must also look at the recovery rate beyond the first hour of delivery, unless your hot water usage is under the first hour supply.  For instance a typical water heater with a 70 gallon first hour delivery may only have a 50 gallon rating on this chart.

Commercial Water Heater’s by BTU’s

40,000 –   51 Gallons per hour

50,000 –   64 Gallons per hour

75,000 –   96 Gallons per hour

100,000 – 129 Gallons per hour

150.000  – 193 Gallons per hour

200,000 – 257 Gallons per hour

250,000 – 322 Gallons per hour