Yes, a residential heater can be installed in a commercial application, however please be advised, the heat exchanger warranty will decrease to 3 years, in lieu of the standard 12 years.
See Noritz warranty policy, terms, and conditions at: http://www.noritz.com/home-owners/warranty/
Use the warranty calculator to check your warranty status at : http://support.noritz.com/warranty-calculator.php
A device used to transfer thermal energy between two or more fluids (e.g. air, water, oil). The fluids are typically separated and not allowed to mix.