We are remodeling our house and main upstairs bathroom is no longer surrounded by any external walls. Because of this our HVAC contractor says we don't need a supply vent in the bathroom. We think that having fresh air/heat in the bathroom is imperative and there is now a skylight in the bathroom so the room will still be exposed to some external sunlight/cold. We live in Minnesota so there are many cold mornings where you would want to have plenty of heat in a bathroom. What should we do? Thanks so much!