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Smoky Wood Fireplace

Help! We have a wood fireplace that has an excessive smoke problem. Smoke will pour out of the fireplace into the house unless a window or door is open until a roaring fire is underway. Then, the fireplace will start to smoke again once the fire is dying down for the evening. I'm not sure if this has anything to do with it, but the house is a SIP home (structurally insulated panel). The house & fireplace is 3 1/2 years old. Does anyone have any ideas why this is happening and how to fix it? Any help is appreciated.

Timothy Miller
Re: Smoky Wood Fireplace

Hi, Check the height clearance of the chimney pipe. It should be at least 2' taller then any roof withing 10' of it other wise down drafting can occur. Is ist windy when this happens? Some time a windward chimney cap helps. Is your house too tight? Do you have a air exchanger? Do you have a carbon monoxide tester? Now- today great time to buy one so you can be warned if to much in the air.

Re: Smoky Wood Fireplace

If your house is 2-story, the FP might be having a hard time establishing draft if it is on the main floor with a chimney that terminates at a point lower than the 2nd floor roof.

This is because of the stack effect created by the tall house: warm air rises and escapes wherever it can at the high ceilings and walls, and this air is replaced by infiltration from leaks in the lower areas--the chimney top would be one of those lower "leaks" if it terminates lower than the 2nd floor roof/ceiling.

This is only one possible explanation, but, whatever the root cause, the question you must answer is: Why is the space where the FP is located being de-pressurized in relation to the outdoor air?

Exhaust fans are suspect. Test to see if turning them on or off makes any difference. Don't forget the dryer exhausts a lot of air.

Ducted forced-air systems, if not designed and installed properly, can also create pressure imbalances that are capable of backdrafting FP's and gas water heaters. Again, test this by turning the furnace blower on and off to see if it affects the FP.

Re: Smoky Wood Fireplace

I had a similar problem and installed a T-top chimney cap this fixed my problem, your case might be differen't but it worth looking in to.

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