The call was to check the bath fan. It wasn’t “sucking” as well as it should. There was also an odour “somewhere” in the bathroom. Well, up into the attic. Found the fan venting. It was plastic, uninsulated and vented out the soffit. It was wet inside too. Wet enough to have it’s own little ecosystem going on inside. What you’re seeing in the picture is a close up of the INSIDE of the venting. Now, I should mention that this wasn’t that old. The bathroom was renovated and this venting was installed with the new fan. It was just the wrong kind.
So, we changed it to INSULATED venting – still plastic and flexible though. The new venting has a poly wrap on it as well, so the moist air stays moist until the outside. Oh, The vent…. Not the soffit if it can be avoided. We changed that too. Now it goes out the gable end.
Another key point to know is to check the installation instructions for the fan. The instructions will specify the size of venting required and, on this particular model, the venting is required to run horizontal for 24″ to 30″ before making any turns. This allows for good flow before the restriction of a turn. If the venting turns too quickly from the motor, it can have back pressure. Back pressure reduces the efficiency of the fan and will make the motor work harder. The extra labour on the motor can wear it out prematurely and will make the fan noisier.
Lots of things to know about the bath fan. Read the installation instructions. All fans aren’t created equal.