As with all gas water heater installations it is very important to have sufficient combustion and dilution air to insure proper drafting of the exhaust products and safe water heater operation.
Gas hot water heater in attic.
A water heater in the attic saves square footage tank type water heaters are big hulking cylinders filled with anywhere from forty to seventy gallons of hot water.
As outside temperatures increase the need for proper combustion air and attic ventilation becomes even more critical.
In addition to all the regular code requirements for a water heater when the water heater is installed in an attic you must first have an attic access hatch that is a minimum of 24 x36 and even more for larger water heaters.
Remember the water heater must fit through the hatch to permit future change outs.
A transfer grille from the ceiling of the water heater room to another room of the house will allow combustion air to be pulled from conditioned space eliminating the flow of hot air into the attic in the winter and out of it in the summer.
N some areas of the country water heaters both gas and electric are installed in attic spaces.