Can I tap into existing ductwork for basement heat?
We just finished roughing in our basement. Everything is DIY. This is our third basement. In our first house we installed electric baseboard heat. In our next one we used the existing heat pump and just added additional duct work. That house was 1800 sq ft and the basement increase it to 2700, all on one heat pump. We didn't have any problems doing this. All three floors were comfortable and our electric bill was not astronomical. This house is 3000 sq ft and each floor (1500 sq ft) has it's own heat pump. The basement will add another 1500 sq ft and we would like to do the same thing. Used the furnace that's currently down there and just add additional duct work. The basement is a walkout on one side with the three other sides below grade. We also plan to use the radiant floor heating pads under the flooring in several rooms down there.
Is this okay? Do you think 3000 sq ft will be too much for one furnace to handle? Will it reduce the amount of heat that gets to the main level requiring the furnace to run longer and harder?
I plan to ask the building inspector these questions when he comes on Monday to do our roughin inspection. I considered calling a hvac company but figured they would just try to sell me another furnace whether I need one or not.
Your thoughts would be greatly appreciated. DH is on vacation next week and we hope to drywall then.