Can someone provide some clarification,or point me in the right direction to get a better understand about Canadian Code (specifically in Calgary, AB) with regards to high CFM hood fans?
When we build our last house, we selected an over the range hood/micro combo. We were told that due to the CFMs of the fan selected (it's around 400cfm) installation would be more because Alberta Code required it to be wired to the furnace ventilation fan. I understand the rational behind negative air flow, potential back drafts, etc and the appliance selections were made early on in the construction process before wiring was completed, so we never questioned the advice we were told. And, the hood fan is definitely connected to the ventilation fan - when the microwave is on, or when we turn on the hood fan the ventilation fan on the furnace does turn on.
Now, both my parents & inlaws are in the process of doing kitchen renovations. And they are both looking at hood fans of over 500 CFMs. Knowing how our fan is wired, they have both asked numerous sale people & no one has ever heard of needing to connect a hood fan to the vent. fan. I decided to do a bit of Internet research and I too am coming up with limited advice on whether this is required or not, and more importantly how it's done during a renovation.
Were we given incorrect information which has caused some disillusion in our mind? Or, are people just ignoring the requirement & avoiding inspections?
The bit of info I have found, I believe some sort of 'interlock' is required which would connect the hood fan & furnace fan, correct? What access is required for installation - are they installed at the hood fan location, furnace location or electrical panel? Ie. Both house have fully developed basements, with finished drywall ceilings, so the ability to pull any new wiring from the kitchen to the furnace room or electrical panel location would be near impossible.
Thanks in advance.