Originally Posted by
Steve D'Gerolamo
As I'm approaching the 1yr anniversary of the purchase of a home in NC (constructed in mid-2005), I hired a local inspector to provide an independent assessment of the condition of the home. The builder's warranty expires on July 10th.
One thing the inspector did not check was the performance of the bathroom fans...he checked to see that they worked but did not have an anemometer or other meter required to measure air flow.
What is the code requirement of sizing of residential bathroom fans (I'm guessing 1-2 cfm fan size per sq ft but the ceiling height in the bathroom is 10' so there's lots of volume here)? Our master bathroom fan does not keep steam from forming on the mirrors and clearing the mirrors and shower doors of steam takes 15-20 minutes after finishing the shower.
I've summarized the punch list for the builder with some photos at
Open Warranty Issues -Lot 1039 Sconset Village
I hired an inspector based on the advice from this forum...too bad I didn't do so when we purchased the home last year. If you see anything on the list or if I've said anything that is no accurate please let me know.
As to the fan, I have a meter to test it with later this week. Steve D
Mechanical fan needs to be 20 cfm continuous or 50 cfm intermittent or greater. Even the cheap ones provide this, I don't think they make them less than this. If you are under the IRC this is all that the builder would be required to install. If the bathroom has a window that opens, a fan is not even required. Room size does not come into play with a bathroom vent fan. Common sense and proper placement however is not covered with the Codes!
A vent fan will not keep the steam from forming in a bathroom. It will help to get rid of the humid air but I have never seen one that can keep up with the amount of moisture that is produced by a shower. About all you can do is to take shorter showers or lower the water temp.
FYI, home inspectors do not test for airflow. Unless you specified this to the inspector this is not a normal thing for inspectors to do. I bet that if you asked 100 home inspectors if they even had an anemometer or knew what one was you might have 5 who would know what it is and only 1 might have one.