I live in Ontario Canada in the Niagara region. We live in a 15 year old home with a new variable speed high efficiency furnace. every year around this time as we close up the house for the winter,I start getting terrible headaches. i used to get them when in the basement but now with the furnace fan running more I am getting them throughout the house.I bought a room hepa are cleaner for the bedroom and it seems to help. The headaches diminish when i leave the house and get fresh air. My question is how do i find a company in my area that can test the air quality in my home and point me in the right direction to improving any problems?