I am finishing my basement and I need to add HVAC to two of my rooms. Can I just simply run flex from the top of the main trunk line going up to the new rooms? The two new lines would consist of one flex duct with one register. I already have two seperate lines coming off of the main trunk to go upstairs. My townhome is 2 stories plus a basement. I just want to make sure I don't screw up the HVAC for the rest of the house.
Basements that get their heat from the same duct system as the rest of the house, have a common flaw. Hot air rises, and cold air falls. Along with the fact that the thermostat is usually on the first floor. So it doesn't know that the basement is Cold.
Might want to put in an electric heater or 2, besides the 2 new runs.