Dear Mr. Pearson:
Thank you for writing to me. We have many heat pumps installed indoors. Some manufacturers are fine with it and others are nervous as they feel they can't control the way that you vent and just say no to the whole thing. When you are ready we will work with you and the manufacturer to make sure it is done right. Generally the heater fan opening is about 24" to 30". Most people then run a duct from the heat pump through a wall or through the roof to let all of the air exit the area. We don't want cold air re circulating back through the heater as that will reduce the efficiency of the heater. Some people get a 25' box of flex duct from Home Depot or they get a sheet metal shop to make a custom fitted metal duct. Then you will need a fresh air intake somewhere in the room. Maybe a screen door, open window or cut a hole in the wall and put a grill. The heater might be discharging 5000 CFM of air so the intake must handle that. It isn't that big of a issue. Then you will have to also have to drain out the condensation that the heater will produce from cooling the air. That might be a few gallons an hour on a humid day. You must get the manufacturers OK before you do it to protect your warranty and obey all local codes. The late fall is really a good time to start this as electricians are not that busy and then as soon as the weather warms in late April or May you are ready to heat and don't have to worry about shipping, finding an electrician, manufactures back orders etc. On some manufactures you can also have the warranty start in the spring when you tell them that is when you are going to start the heater. Please ask us for the names of who will do that when you are ready.
1 800 741 9956