Hello, I recently worked on a timber frame home that we put Sips on. It is now in its first winter of use. We seem to have a problem with the house being built too tight. It has both a gas stove and a wood fireplace. When a fire is lit without a window open or a fan on the carbon monoxide detector goes off.

Our current ideas for a fix include some sort of vent or a fan that is only on when there is a fire. I'm sure someone else has had this problem. How did you fix it?

Hi Gumphri.The tightness of the house is not so much the problem as the balancing of the air flow with these combustible appliances. You should have a certified professional inspect or advise you on a remedy. Here are a couple of links for information purpose.

http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_004.cfm
http://www.cmhc-schl.gc.ca/en/co/maho/enefcosa/upload/wood_heating_EN_W.pdf

did you install an ERV/HRV system?... if it's tight you gotta vent

Thanks for the links. This is a new subject for me. They were a good read.

This is the first house I have worked on that doesn't have forced air heating. The primary source of heating is in floor heating from a boiler.

I will be honest most of my wood fireplace experience is in camp tents. In those places back drafting is not a major concern. In a house this is a different story.
Yes, a professional has been contacted. That is my friends department. Because Sips are rare in this part of the country he may or may not have experience with them. That is why I'm asking here.
There is venting to replace air but I don't know what kind of unit it is. This house also has a boiler and in floor heat as its main heat source.
Would I be correct in assuming that if we kept the inside air pressure greater than the outside air pressure that there would be no back draft from the fireplace and the largest source of carbon monoxide would be reduced?

Thanks,

Leslie Ball

Here is another link to info on house ventilation with an example of no forced air system. Did the owner install the fireplace? Is it old/new ? What are they using for fuel?
I know it is getting cold out there but I don't think there is a safe reduced level of carbon monoxide.


http://oee.nrcan.gc.ca/residential/perso...tion.cfm?attr=4

I guess the easiest way out would be to install a fresh air supply kit directly to the fireplace.
You can have an airflow test performed to see the actual #'s, but if you're in the sticks, you might have a problem finding a company to perform such test.
The standard is to have a mechanical ventilation system capable of ventilating at a rate of 1 cfm for every 100 square feet of occupiable space plus 7.5 cfm per occupant.
http://www.airkinglimited.com/pages/exhaust/ashrae3.html

Right now I am in the same situation, our foam house is so tight, I'm heating 2500sqft with a 80,000btu propane furnace only ducted to the basement... lol. The leakage through the subfloor is sufficient in keeping the main floor and loft comfortable. I will be running a direct air supply vent to our woodstove, and installing low cfm exhaust fans in bathrooms and kitchen.

Yes, there is one apparently its the problem. We had it tested and its pushing out more air than it is bringing in. I suspect the problem will be fixed by replacing/tweaking this unit.

Thanks,

Leslie Ball