Originally Posted by dellposter
I have a mid nat gas forced air furnace and gas hot water tank. The hot water tank directly exhausts outside, while the furnace has a fan to push the exhaust up a chimney (no draft hood) i also have a natural gas fireplace that has b-vent. I have been fighing trying to keep my utility room warmer as my kids bedroom is directly above. The only cold source i found is the fresh air intake. It is currently a 4" insulated pipe that goes down to the floor then back up 3' like a p trap. It originally just hung in the air, and i thoght the p-trap would help but it doesn't. It has cold air coming from it even when everything is off. I am too nervous to damper it anymore casue there is the chance that all appliances could run at the same time. Should i worry about doing this, or is there any other suggestions on what to do? Oh ya i have a venmar HRV. it has a single motor so whatever it oushes out it draws in so i assume its balanced. I even shut it off and still have the cold air issue. All new windows in the house. I had it tested and its a pretty tight house.
Lets start all over again. You are calling this 4" flex pipe a fresh air intake. A fresh air intake is a 4" pipe that comes from out side and goes into the return air of the furnace. It would be there to bring fresh breathing air into the home.
Now we have another thing called burner make up air. This is to give air to let the burners and natural draft stacks work. .
So you say your water heater is power draft to the out side, and does it bring in its own burner air in? Does your furnace have metal pipe and a fan, and does it go into a chimney to the out side?
Is your furnace room sealed off with a solid door on it?
What is the BTU rating of the furnace?
How many sq. feet is your furnace room?
The reason i am asking these question, is if your furnace room is tight and you have a fan assisted furnace, then the 4" pipe is not large enough.
Where is this fire place at in the house? Paul