Okay, first off, I have a 1970's vintage house, not super airtight but I have made some small improvements (insulation, caulk). Original, I think, Thermopride oil furnace, has been serviced every year since new, by the same contractor. I installed a new powervent water heater a little over a year ago, and we have a gas dryer. The first couple of winters we were here, we never smelled fuel oil, but the last three winters we can now smell fuel oil. Changes: 2 years ago I rebuilt the 2 feet of chimney sticking out of the roof( I'm a bricklayer), for some reason I went 1 course higher with the brick than the old chimney was, we have been putting that shrink wrap plastic on our windows the last few years, I partitioned off a wall in the basement near the furnace and dryer (for my woodworking shop:)). So any way I think yesterday I may have figured out what is creating this smell in the house, there is a neg. pressure coming out of the barometric damper, the wife and I were discussing this, and she said she only smells it when the dryer is on, then later last night I smelled my clothes that had been in the dryer and they stink like fuel oil exhaust. So are all or some of these changes creating this negative air pressure? If so what can I do about it? Any help would be appreciated. Sorry if my post is long, I just wanted to give the most info possible. Thanks in advance, Tom.

I have an air exchange/heat recovery system in my house. I really would like to tap into the input and output of the duct used in this system for my root cellar. Although my root cellar is cool, my squash and other vegetable were not keeping as long as I would like. They were getting moldy and just not staying very well. I'd like to control the temperature and ventilation of this root cellar via a controller. Since I live in a northern climate I can duct in cold air to keep the temps cool and exchange the air every so often to keep the air fresh. I am wondering if I can put y-fittings immediately at the input and outputs of the air exchange system duct work. I would then put dampers on both legs of the y-fittings so that the root cellar and air exchange system air stay separate. Is this doable? I don't want to unbalance my air exchange system, yet also don't want to add two more holes on the outside of my house to accommodate my root cellar ventilation if I can avoid it. If the y-fittings will work, do I have to oversize them to accommodate both systems using the same input/output? I wouldn't think oversizing is needed unless both system are on at the same time, which is certainly possible. Currently, the air exchange input/outputs are for 6" duct. Would I have to make the openings 8" along with the y-fittings? I'd then use 6" reducers on each leg of the y-fittings to accommodate the 6" duct for the air exchange system and root cellar. I would really like some professional advice before proceeding.