Here is an echo to all the ahas,& wows. I have a room about the same size for crafting which uses the same a.c. Love it, for the a.c. but need an auxiliary heater because the heat pump in it is inadequate to keep up with the GA cold. I was really bummed out when I had to plug a little ceramic heater into the floor to heat the room. (Never did like swamp coolers or heat pumps.)
Is that a heater behind the vents to the right of the fabric, or a cold air return? Where/what kind of heater are you using?