Block Chimney Repair

[SIKSUKR]

What I was refering to was the direct vent system on my furnace.Instaed of the usual chimney vented outlet,more and more systems have gone to a forced draft direct vent,meaning the exhaust can be vented right through the wall.It has a fan that creates the draft that is missing without the rising of hot air up through a chimney.That fan is sucking air out of the house which makes the pressure in the house lower(negative) than the outside(positive).Pressure wants to equalize so it finds a way to get into the house.The easiest way especially in the more modern well insulated homes today,is through a Chimney,even with the damper closed.What I did when I still had my forced draft system was to cut a vent in the wall next to my furnace and installed a small heat register louvered diffuser so the make-up air would come in right there and not through my chimney.The diffuser louvers could be adjusted to satify the make-up requirements.Not the most efficient way but it worked.Ultimately I removed the forced draft because of the noise it created(it was below my bedroom)and installed a metal insulated chimney.Works great.