Hello: If you could go with a direct vent gas heater, the potential pressure problems in the room wouldn’t matter. A heat pump likely won’t fit as they have requirements on room size which this room doesn’t seem to meet. Also, there will be an upper limit on temps a heat pump can function in. If there were a way to duct the heat pump so it could provide some cooling to the house in summer and heating in winter, that would give you a nice two for one :cool:. Are there any other choices for heater placement?