My fireplace insert is in my family room which, unlike the rest of the house, is over an unheated crawlspace (main part of house has a basement). The family room obviously gets quite warm, but I'm thinking that I may be losing significant heat through the floor due to the cold air below. I'm aware of the modern thinking that says not to insulate crawlspaces (at least the floor). But would this advice still be true in a situation where you are generating your heat right above the unheated crawlspace? Any advice would be appreciated.