The gap between commercial and residential water heaters may not be as wide as imagined. Depending on the application and size of building, these two devices may even overlap.
Texas energy provider Reliant Energy notes two major differences between commercial and residential water heaters: the size of the storage tanks and the gas input levels (for gas-fired heaters). Residential heater tanks typically are no larger than 100 gallons, while commercial tanks do not exceed 250 gallons. While residential heaters usually handle gas inputs up to 75,000 British thermal units (BTUs), commercial units intake 1 million BTUs.
While commercial water heaters are designed for commercial applications, residential heaters may serve just as well in some situations. Reliant Energy claims that residential heater may be appropriate for small commercial facilities and even some larger ones.
In some situations, a commercial water heater might prove more effective in a residential application. In cases where a water heater provides heat for living space and domestic water usage, a commercial boiler can handle simultaneous demands better than a standard residential heater.