Chimney Drafting Seems Un-Solveable
My house has two chimney's - one drafts out and one that continues to perputually draft into my house. We have an oil burner and two hydro-air handler units. I have had multple people to my house and none can solve the issue. Some of the fixes I have tried to stop the chimney from drafting in my home:
1. Installed top mounted damper to drafting chimeny - no improvement
2. Installed a "Plus Air" system to the air handler in the basement - modest improvement, but not fixed
3. Installed a vent to the boiler room that introduces air from the outside directly to boiler room - improved, but not fixed
I've done other things, but those are the three primary areas things I have done and still no fix. Further info:
The draft was coming in from my chimney and also from a vent we have in a flat cooktop in our island. Once we installed the vent to the boiler room, the cooktop vent has virtually no air flow coming into the home, but the chimney is still a lot.
If I want to equalize the pressure or to get the chimney to draft out, I go to the basement and open any window about 4-6".
My boiler room has a wooden door with slats so I tried putting plastic on the door and the gap between the door and the floor to simulate if I made that room more air tight, if it would draw more from the outside vent. That did not solve it either, though I could see that sometimes the chimney would draft up and out of the house, but mostly it would be coming in the house. The way I know this, is I tape plastic over the opening of my chimney so I can see which way the air is going.
When we had a fire, once the flu heats up the smoke will draft out, but once the fire goes out, the air comes into the house and the entire house smells like a smoldering fire for weeks. We haven't had a fire for over a year now and while the smell is gone, the winter cold air is steaming into the house and making that room drafty and cold.
Does anyone have any suggestions on how to fix this pleas? We are very desperate and I have spoken to many professionals and none of them can figure out how to solve this issue.
Thanks in advance and if you need any other info please let me know.
I'm not sure I was clear. Opening the window in the basement does not let warm air out; rather, cold air streams in to the house. Basically the boiler or something that I can't figure out is drawing air from the house. If no window is open it draws it from the chimney I assume because it is the easiest place to get it. If I open the window that becomes the easiest place to get the air needed and so the chimney stops drafting in the house. The question is why does the boiler or something in the basement need more air? I have or tried to introduce air for the boiler already and yet it does not seem to be enough.
what I am looking for is a solution for that please.
How old is the house? Is it a 2 or 3 story?
Post pics of your boiler room and the chimney in the boiler room, including its barometric damper. And tell us the size of the chimney.
Also post pics of the chimney that has the down draft.
And list what size air intake you made for the for the boiler.
Doesn't the fireplace have an outlet damper and glass doors you can close?
I think you were on the right track with the plus air, outside air that is. A fire can use up a lot of air. You might want to put in a 10" or larger duct to outside air with a closable damper. But if it were me I would put a stove in the fireplace, it burns more slowly and thus needs less air. Or just seal up the fireplace, those things use more energy than they heat!
Two words, Draft Inducer.
Answers to Questions and Link to Pics
Q: How old is the house and how many stories?
A: Built in 2001 and 4 total floors (walk out basement (where boiler room is), first floor (where both chimney's are located), second floor, and finished attic.
Q: Doesn't the fireplace have an outlet damper and glass doors you can close?
A: No glass doors and both chimney's have iron dampers near the top of the mouth, which are closed. On the chimney that drafts in the house, I also installed a top mounted damper, which is also closed
Just for further clarification, the drafting problem has nothing to do with a fire. We have not had a fire for over a year. The chimney just drafts into the house b/c the boiler is pulling air from the house I believe.
Q: Post pictures - the files were big so I posted them at the below site
I have pictures of the boiler, the top of the boiler, the barometric damper which is about 6". I also have the new intake valve - also 6" and my Plus Air unit. Finally I have some pictures of the chimney that is drafting.
Of note: the chimney that is drafting is NOT the chimney that is sharing a flu with the burner. It is a totally separate and on other side of the house.
Of the question, what size is the chimney, I'm not sure how to answer. How tall, the opening?, can you be more specific with what info you are looking for?
The draft inducer? That read like it may help, but does it matter that my chimney that is drafting doesn't share a flu with the burner? Who would be an expert in something like that a contractor, a HVAC specialist?
Thank you everyone for all of your comments. This has been a really frustrating problem that I have spent a lot of money on for no real solution. Any help is immensely appreciated again.
I don't know a lot about chimney problems but I have had a little experience. I have lived in four different homes with fireplaces and none of them worked well.
The height of the fireplace opening should be shorter then the width. On this particular fireplace, I had to mount a piece of flat metal across the top of the opening and the fireplace worked fine.
Another thing to be considered is the chimney height in relation to the highest point of the roof and the surrounding trees close to the home. The top of the chimney should be slightly higher to prevent down draft.
I would suggest you look into the design and the chimney height.
Chimney size. Its inside dimensions, and its height.
You got some code violations there. The flue pipe is single wall. And going through an area with combustible material(the 2X4's) without enough clearance. Along with that electrical recep that is also too close.
Thats another problem though.
Almost looks like an 8" flue with a 6" barometric.
Does your boiler maintain temp 24/7?
Air always takes the path of least resistance.
So apparently. Its easier for the cold air to come down that chimney and travel to your boilers chimney?
I would check to see if your kitchen hood is drafting out constantly also. And drafting more then your intake hood brings in naturally.
I think you have more then 1 area that is drafting air out of your house.
As a test. If you would.
Turn off your boiler. Seal the door to the boiler room(use plastic and tape it completely air tight).
Then do the same to that fireplace.
Now go and see if other areas have a draft coming in. Such as your range hoods make up air unit.
And your other fireplace if you have one.
if you have an attached garage. see if the door now pulls open with those 2 areas sealed.
Do you have an attic, and if so do you have an access to it from inside your house. is it sealed shut/air tight if you have one.
To me it sounds like the house has a Heat rising draft through the home. Multi story homes can do this. A simple example of this is if you open a window on the top floor and a window on a lower floor you have now created a chimney. The heat rises out of the top window and brings in air from the lower window. Open a window on the 1st floor instead of the basement and see if you get the same results. If it works the home itself is acting like a chimney. Some Items that can cause this are openings like loose atic hatches, bathroom exaust fans and can lights.
The inside Chimney dimensions are as follows:
Back wall width - 32"
Back wall height - 35"
front wall width - 42.5"
front wall height - 32" to the edge of the rocks, but they hang down, so if you go to the other top it's about the same height
Depth - 21.5"
Height of chimney - I don't know exactly, but it's about 4 stories. The top is just above the roof line, but it's questionable if it is the required 2 foot above the roof line. It's close. Another consideration, the roof line towards the other chimney is probably higher and that chimney is also probably higher. It's not a lot , but probably higher. A contractor said b/c the two are a enough of a distance the in drafting chimney did not have to be the highest point, but nobody is really that sure.
Our kitchen hood, which is a vent in a flat cooktop that actually has the vent going down the cupboard and then out of the house below the floor in the kitchen WAS drafting a lot of air into the house in addition to the chimney. However, once we installed the simple open air return to allow air into the boiler room the air flow out of the kitchen vent feels like almost nothing now.
I have an attic, but it is almost all finished. I weather striped the door to the attic and the carpet goes pretty close to under the door and I did not notice any difference (but I have not done your test yet). There is one room in the attic that was not finished and this is where the other air handler is. That door has also has a weather stripped door and I put something to block the bottom of the door (not air tight, but blocks most of the air).
The other chimney (the one that also has the boiler flu in it or next to it) would draft to the outside; however, I duct taped the iron damper at all the seems to prevent the air (heat) from drafting out of this chimney. Seemed to do the trick when I do tape plastic over the chimney I see no movement.
I will try and do the test you suggest; however, I had a blower door test done last winter and they did not find any place my house was leaking air meaningfully, which I believe is what your test is trying to get at. I have read about the stack effect, but I can not pinpoint where the air could possibly be leaving the house from. We do have lot of recessed lightening, but I find it hard to believe that could cause this much negative pressure in the house.
I know the chimney may not be perfect, but I think the larger issue is the need for the air in the basement (either b/c the house is loosing it elsewhere or b/c the boiler needs more for some reason) b/c as you point out we do get drafting in from other sources. It just so happens that that particular chimney seems to be the path of least resistance. What I hope to find out is how to fix the negative pressure problem and to equalize the pressure in the home.
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