7. What to Avoid
A type of gas fireplace to avoid in Canadian housing – the vent-free gas fireplace – is available in the United States. As the name implies, these units do not vent to the outdoors; all the combustion gases (including carbon monoxide, carbon dioxide, nitrogen oxides and large amounts of water vapour) are released directly into the house. These fireplaces can cause serious indoor air-quality and moisture problems, particularly in airtight Canadian homes. They are not approved for use in Canada.