I had a bathroom exhaust fan installed by a handyman. This bathroom has not previously had a fan. It was a top of the line fan, but it doesn't work properly. The bathroom is very foggy after a shower. The handyman tried another fan, but same problem. He brought in a "ventilation expert" to assess the problem. This man said we had no makeup air vent in the house. He could install one for $400. What is a makeup air vent? Will it solve our problem? Is $400 reasonable?

I think someone is insane and that is the vent expert. I do not care how tight a home is there is always room to exhaust a small bath fan. Make usre the handyman piped the bath fan to the outside of the home. You should be able to look out there and see the vent cap and damper assemble and when the fan is running there should be air blowing out.