Can Make-Up Air units that have indirect gas heat be mounted indoors?
Yes. Indoor installation is selectable in CAPS. With that selection you will need to specify the type of combustion gas venting required. See page 16 of the Indirect Gas-Fired Technical Guide for specifics. Structural support requirements are by others. Note – all Greenheck indirect gas units are power vented. Indoor mounting of units with evaporative cooling is not recommended.