[cherylallismom]

We are finishing our basement. We insulated with rigid foam and sealed the headers. There are two interconnected finished spaces of about a total of 400 sq feet, plus a finished bathroom. There's a utility space that is about 150 sq feet, which includes the gas furnace and hwh. The second floor is an 8 year old addition with 6 inch framed walls with fibreglass batt insulation and 14 inches of blown in insulation in the attic. The main floor is a 60 year old double brick bungalow with no insulation and new windows and doors. The whole house has always been cold in winter. There are places where you can feel real drafts, but you can't actually find them coming from anywhere. Now, with the basement just insulated and drywalled, the problem seems even worse on the main and 2nd floor. Its not even winter temps yet and it is really cold on the 2nd and main floors. You can also feel a huge draft coming down the stairs from the 2nd floor to the main. But again, can't find a source of the draft. The main and 2nd floor are 650 sq feet each. The main floor is open concept. There are 5 supply vents and one good sized central return vent. On the second floor there are also 5 supply vents (one per room, incl a large closet). There are two moderately sized returns - one near the ceiling in a bedroom. One near the ceiling in the stairwell. The basement is not quite finished. There are 2 working supply vents at the moment and there will be a third. There are no returns yet, but the plan is to install two at floor level. At the moment there are no doors on the utility space, so the air is moving freely throughout the space, in theory. I'm at the point of hating my house right now because of this problem. HELP!

[hvac1000]

I suggest you have a manual J done for sizing and a manual D done for duct sizing. Having these done by a professional will cost you a few $$$ but the results of the J and D survey will set you on the correct path to cure your problems. Right now all you can do is a guessing game as to what could be causing the problems and you need to find out exactly what the cure is.