@Neat Hat wrote:
In renovating my bathroom, I’m going to be putting in an exhaust fan, there wasn’t one previously. The bathroom is in the basement of a split level. It is going to be a huge pain in the ass. The joists run the wrong direction, so I can’t just run it out the outside wall in the bathroom, I don’t have ductwork (electric heat), so I can’t run it into the air return. My only option, it seems (other than half-assing it and just venting it into the laundry room) is to run it through the ceiling, across the master bedroom, and out the wall on the other side of the house. Also, it is going to be a pain to run the vent line, because in that ceiling, there are bunch of drain pipes, water piping and wiring that are in the way. Not sure if I’ll even be able to get the vent around it all. Gonna suck to get done, but my wife insists on the fan, so I guess I’m going to try to get it figured out.
Depending on your ceiling height, we sometimes drop ceilings in showers to put the fan/light combo right above the shower. We usually do this in homes that have a small separate room with the toilet, then they get 2 fans – a fart fan and a steam fan…
Please do not vent it into the plenum, air return, or into the laundry room, the point is to remove the humidity from the enclosure, not just move it to a different part. Is running a vent vertically an option? Getting it up to the attic then out a side wall or gable end? Most fans have a 4″ round outlet, get some 4″ flex duct, and transition to a 3″ thick rectangular duct in the cavity and then whatever you fancy in the attic.
Also, in my case at least, the Panasonic Whisper fans was well worth the extra cost. Put it on a timer as well, not just a switch.
There are exceptions to this…
1. if the house isn’t that tight – plenty of turnover – then just moving it from an area of high concentration is enough
2. do you already humidify like crazy in the winter? If so venting into the house will cut down on that
On the other hand if you aggressively dehumidify all summer and or you can tell your AC is dumping water like crazy then you definitely want to get that moisture outside and not just pump it around the house. It not only can overload your AC or dehumidifier [mold potential] but is costing you money to condense that water. Energy to condense or boil water is about 1000 BTU/lb. 1 gallon is 8.3 lbs. So for every gallon you dump is about 8,300 Btu equivalent of electricity down the drain. That if at 100% efficiency which it likely is not.
In my basement bath – getting water out is critical. I dehumidify a lot. Second floor bath not an issue – our house is old and very drafty – not even air conditioned in most rooms. Just open a window. That is NOT the case in most newer homes.