One of the issues to consider when adding a range hood, or replacing one, is whether it will cause depressurization problems in the house. If the exhaust flow of a range hood (or any other fan) causes high levels of house depressurization, there are some possible negative consequences:
- Backdrafting or spillage of vented combustion appliances, including fireplaces and woodstoves
- An increase in radon entry from the soil
- An increase of air entering the house from attic spaces or wall cavities
- Drafts from the outside
The bigger the fan and the tighter the house, the more depressurization that is likely to occur.
Have you encountered this in your work? Have you seen instances where a newly installed range hood requires some monitoring or the provision of make-up air? What levels of depressurization have you seen created?
Back when I was testing houses in the eighties and nineties, we saw several houses exceed 20 Pa of depressurization. Are we seeing that today?
The gradual disappearance of natural draft appliances (those with chimneys) and the availability of consumer carbon monoxide alarms have reduced some of the dangers.
We would be interested in hearing about your experiences.