Reduce bathroom fan vent from 4" to 3"?
I need to install a basement bathroom fan. It will run about 1 1/2 feet and out the wall. I'm pretty sure I have enough space for a 4" vent but I may only have enough for a 3".
I haven't found a fan/light with a 3" vent. Can I reduce from a 4" to a 3"? If so, should I look for a fan with higher cfm (or lower?)? It's not a very long run - any thoughts would be appreciated.