We've seen it probably more than 100 times. In an attic, the bath fan discharges directly into a pile of insulation. You would be surprised that it's more common than many people realize! If you don't know the condition of yours, it's worth a quick investigation. So, what are the indicators of a properly ventilated bathroom? Here are a few tips.
1. Select the correct size bath fan. Many have a square footage chart included at time of purchase, but there are tables available online as well, such as this one from HVI:
2. Ensure adequate make up air can reach the fan. As pictured, allow a minimum of 3/4" clearance under the door, and even more if possible. Use caution, however, that hollow doors only have a small solid rail at the bottom which could limit the cut off.
3. Always terminate the ductwork to the home exterior. In the photo, the duct is attached to a pre-cut galvanized sheet, and connected