I would agree with some of the other reviews, replacing an existing fan with this one can be a bit more challenging as this one is designed to have full access from the rafters below with the ceiling opened. With some planning the installation challenges can be mitigated if you are doing a replacement like I did, but it still had its points during installation that wasn't fun, unfortunately the wiring was also on the opposite side from the old one and the new one is on the side in a cramped spot in the attic with poor accessibility so it required some prewiring of some lengths of Romex before setting it in place, so keep that in mind too if it is going to be in an area in the attic that will make the wiring hard to access.The exhaust fan works great, and is much quieter and more powerful than the one it replaced, I think the old fan was undersized as there was always still lots of moisture on the walls and ceiling and it was starting to cause mold issues (why proper CFM is important), but this one keeps the moisture in the bathroom during even a hot shower to almost nothing now. The LED light is very bright, we run the fan off a timer while we shower and many times we don't need to turn on the main lighting in the bathroom when this is on. The heater works pretty good, it seems like it is a little louder than I would have expected and noticed a slight vibration sound when it is on, but it has heat coming out almost instantly. I did an amp check with the heater on and it draws just a bit over 12A, it calls for a 20A circuit and 12 AWG wire for the heater and that's exactly what I used and pay close attention if you are going to use a timer for the heater and make sure it is rated for it.