Bests & Worsts Reviews from Amazon

I had high hopes for this fan, as I have known Panasonic fans to be good quality units. As a high-performance homebuilder, I often recommend them to others and specify them for projects. I won't be recommending them in the future. After installing the FV-0511VQ1 in my own home to replace an older undersized Broan, the problem with the Panasonic fan started immediately. With the first shower in the bathroom (not extraordinarily hot, and less than 10 minutes long) condensation was dripping back out of the fan grille onto the floor. The water was dripping out of a weep hole in the fan body which appears to be designed for that exact reason - to let condensation drip back out of the unit. After 4 or 5 phone calls in the course of a week's time to Panasonic technical help (with no helpful advice and even some condescension directed my way), the dripping problem persisted. In the meantime, I did the following in an effort to diagnose the condensation problem: I tested the air volume movement with an exhaust fan flow meter and had a repeatable measured airflow rate of 90 CFM. WIth the static pressure from a duct, that isn't bad for a fan rated at 110 CFM and it exceeds the necessary ventilation rate for an 8' x 10' bathroom. The recommended air changes per hour for a bathroom fan is 8 ACH; for my bathroom with an 8' high ceiling this equals an air change rate of 5,120 cubic feet. The 90 CFM rate I was getting equals 5,400 cubic feet per hour. So I knew that airflow was not the problem (yes, the damper was operational and not taped shut from the factory). I also used an infrared camera to check the thermal signature of the fan and surrounding ceiling area from below, with the fan both off and running, to make sure no cool air from the unconditioned attic was being pulled into the fan housing and causing condensation. The IR image showed a completely warm installation with no cold air leaks in both running and standby conditions. The condescending Panasonic technical adviser insisted that condensation was occurring in the duct and running back into the fan body and out the grille. To check this, I pulled the fan body down out of the ceiling (this is actually one nice feature of this unit) immediately after a shower which caused the fan to drip. I stuck my hand and forearm about a foot or more into the duct and it was dry - no condensation or liquid water there. So that theory is invalid. Let me pause and state a few other things here: The fan was installed with an insulated duct run of approx. 7 feet to a wall vent terminal, with no elbows, kinks or hard bends. The duct formed a gentle arc, and ran slightly up out of the unit to get above the ceiling joists and then sloped downward to the exterior wall. The entire fan housing was fully enclosed in insulation. Everything was done to best practices - the typical arguments of uninsulated duct, hard 90-degree bends, etc. did not exist in this installation. The fan was installed on a timer and ran for at least 15 minutes after each shower to clear any possible condensation in the duct. Not really an issue anyway, as the dripping was happening immediately after each shower was started. As one last ditch test, on several occasions I started the fan and let it run anywhere from 5 to 15 minutes before a shower was started to try to "pre-warm" the fan body with warm, dry indoor air. Condensation happens when warm moist air contacts a cold surface, so if the fan body was still somehow too cool this would correct that issue. Short answer - no change, the Panasonic fan still dripped A LOT of water - sometimes several teaspoons worth - onto the floor (see photo). Panasonic ultimately had no answers or explanation for the problem, and told me to return the fan. I finally did so, and replaced it with a Broan/Nutone RN110. The Nutone works perfectly, is just as quiet as the Panasonic, and doesn't rain water from my bathroom ceiling. All other installation conditions are the same - the only thing different is the fan unit itself. I really wanted to like the Panasonic, but because of some kind of design flaw that causes condensation in the fan body, I can not recommend the FV-0511VQ1 fan to anyone.