‘Way to go’ Panasonic, for producing a bathroom fan that leaves even other Energy Star rated fans in the dust. Fan efficiency is measured in CFM or cubic feet per minute per watt, meaning those units that can move more air in a minute on a single watt are more efficient. Panasonic’s Whispergreen FV-08VKM1 model has raised the bar with a rating of 7.1 CFM/watt.

Panasonic has also taken care of backdrafts with a built-in damper and will warranty your unit for 6 years, compared to the typical 1, 3 or 5 year warranty on other fans.

Most other Energy Star rated fans on the list hover at 2.5-4 CFM/watt, leaving less efficient Air King, Broan, and NuTone models green with envy at a 1.8 CFM/watt rating. As you may have already guessed, the Whispergreen generates very little noise, specifically, only one third of a sone.

To give you some perspective, the noise level of a regular conversation one meter away is between 1 and 4 sones. Thank goodness the Energy Star rated NuTone unit I bought last season (3.3 CFM/watt and 1 sone) has neither been unwrapped nor installed. I know I have the receipt here somewhere.

The only potential downside I can see is that the Whispergreen is outfitted with a motion sensor. So in the long run, energy efficiency gains may be hampered by the thing blowing when you don’t need it. You could cut your energy losses by setting the low/high delay timer so that the fan runs at lower speeds unless the bathroom is in use for longer periods such as during showers or baths. But, chances are, the motion sensor may save you energy potentially lost from forgetful family members leaving the fan on.

A quick Ebay.ca search returns results for sellers asking between $145 and $152 Cdn plus shipping. Through bizrate.com I found the Whispergreen for $126-$240 USD plus shipping. Or, for those in Ottawa, support the Enviroboutique where you can find a unit for $250.

Resources

Whipsergreen 80 CFM Ceiling Ventilation Fan
Energy Star - Ventilating Fans
Energy Star Fan Ratings (pdf)