Panasonic WhisperGreen Select Dual Speed Ceiling Mount Exhaust Fan, Customizable, 30 to 110 CFM, FV-0511VKS2

This is an efficient DC motor based fan. Has a high (pick-a-speed 50,80,110 cfm) and low speed (basically a percentage of top speed) as the FV-0511VKS2 has the built-in timer/low speed option module pre-installed.I was having trouble getting this to run at low speed. This was an upgrade installed by the builder in new construction (bought this as spare/diagnostic unit). The builder threw in the occupancy and moisture sensor optional modules. Which in the end was cause of my issues and I removed them.The lo/hi speed is controlled by a separate switch. The fan was always running in high speed mode. Operations of the fan switch to high pick-a-speed ifa) manual switch on,b) occupancy PIR detects people, orc) moisture too high (module has 30-80% detection level)(b) and (c) are so called point demand detection sensors and if so detected sets the fan speed to high a default of 20 minutes after the sensor no longer detects that condition -- essentially a run-on timer.What I wanted:1. manually turn on power to fan2. manually select lo or hi speedI use a separate Leviton timer switch for power and for controlling how much time the fan runs.What I got was high speed all the time. Part of it was occupancy switch was always detecting people when builder was trying to adjust it. I ended up removing this optional sensor.The 2nd issue is, its summer and even with AC the humidity is above the moisture sense setting so it too was calling for high speed all the time. I ended up removing this optional sensor.And now it does what I want. When on low speed I have to use a flashlight to look up into the grill to see if the fan is actually turning (it is). That quiet. My purpose for using the low speed setting is air change turn over in the house, both in AC but especially heating season. I used acoustic sensor and the low speed setting was just 1-2db above steady state house background levels - super quiet -- when measured 1" away and 1" into air flow of inlet grillI also found that when measuring outlet air flow on the diag bench and I stuck the air flow meter into the duct output at the unit, the back pressure triggered the unit to increase rpm level to compensate. This makes sense in that if you have long duct run the resulting resistance for the air flow can be compensated for by increasing the fan velocity.All around, super happy with the two units I have installed - after 18 months working great and its quieter in high speed mode vs most fans/houses I've had experience with (short of the air-2-air heat exchanger unit I had in my northern clime house which was always undetectable in noise levels). And the low speed mode is near undetectable.

This fan was the third we have installed in our home. The feature set of this fan and the ease of installation as a replacement unit are exceptional. The noise level is the best available and with the optional moisture sensor, we never have a foggy mirror or problems with mold growth in the shower. I highly recommend this unit to anyone interested in keeping their bath space ventilated with no fuss and very little noise.

These are awesome. Almost silent and move a lot of air. Panasonic stands behind this product and has designed them to be repairable if needed. We've use Panasonic fans exclusively for years and have had great success with them.

This is the second Panasonic fan I ordered. The first one failed a year after the warranty expired. It would no longer turn OFF! It seems the electronics were broken. I ordered this as an expensive replacement unit, but Panasonic changed the layout of the plug! Now there is a 5th wire (ground) added, which was not in the older unit that is no longer available!A nice fan - but I hope that Panasonic can work on the kinks and that this one lives longer!

So so quiet. Best fans ever! they've single-handedly solved our home's humidity issue. Saved us thousands.

With the slightest suction from the air duct the fan stops operating . Cost me twice as much to take this garbage fan out and install a new one in. Has no power.

i have installed these for other people just as a friend, but they need to be vented out the roof never out the sofit because it can get pulled back in at other sofit vents causing possible mold problems??? they just work very well also it would be wise to add the insulated flexible ducting also.. take your time

I am building my house and only want top end equity installed. That is why I purchased the Panasonic whisper fan. I also ordered the new model of the whisper warm that has LED lights but had to get it from a local supplier.