Sunseteco
New Member
Well I have been scouring the web and have tried all the calculations to determine a new fan size. I am almost done installing my new tub and shower (just a tub previously) and I am thinking that a new fan is not a bad idea, since I will now have a shower also. Now the bathroom is just about 8x8 with an almost 8 foot ceiling. I have found 2 different calculations which are fairly close to one another....lets just say 70 cfm is what they are calling for. Would a 90 cfm fan be sufficient? too much? I am not really concerned with energy loss. I just want the moisture and smells to be removed quickly. The run up thru the roof is probably 3 to 4 feet from the fan so the run is not long at all. The current piping is 4 inches with no bends. It does have the flexible, insulated pipe which I could change if need be. I have also cut the bottom of the bathroom door so that there is a 1 inch gap under the door for replacement airflow. I'm just curious what you pros out there are doing and if the calculations on the web are legitimate or if there is a better method of sizing a bathroom fan. Any thoughts or opinions are very welcome. Thanks to all.
