I have a bonus room over the garage that is too hot most of the time. I have PCs as well as a video projector in the room so it has a significant extra heat load.
The main house is 1960 sq ft and the bonus room is about 440.
My current HVAC equipment is a Goodman 3 ton 16 seer dual stage heatpump and a 80% furnace with a variable speed blower. Currently there is one Honeywell 8000 t-stat on the ground floor.
The bonus room has two regular sized registers and a return.
I have spoken with two HVAC contractors and one is pushing zoning while the other is pushing mini-split. Apparently the zoning setup is relatively straightforward (one main trunk to the 1st floor and a separate trunk for the bonus room)
The zoning cost is 50% - 66% the cost of the mini-split.
I would like to save the money, but I also want something that works well. At first I was in favor of the mini-split since it would be a independent system, but now I think using my existing equipment with the zoned system might be a better way to go.
I'm just looking for a couple more expert opinions