This past summer, I built a 2-story, 24x30' workshop. When the weather gets warmer, I will begin insulating and sheetrocking the walls, and making it look nice in general.

I'm considering adding a Gas, hot-air furnace with A/C coil. You know, the kind that most homes have. I am thinking about a "real" furnace for the following reasons:

1. 95% efficient
2. tax credit
3. integrates A/C without much difficulty
4. Can heat and cool both floors
5. Avoids window A/C units that block my view
6. Ductwork provides the best air circulation to prevent hot/cold spots
7. The upstairs may become a nice living area at some point (especially if the wife kicks me out for spending so much time/money for the shop)

My quote from a local HVAC contractor is $7900 for everything, including 2 ton A/C and furnace. I can buy the exact same furnace and A/C coil/compressor for less than $2000. I'm considering installing it myself and have been doing some research. I think I can do it with help from some friends.

I haven't seen many people taking this approach. Is it the cost or complication? Please let me know your thoughts.

Bob