This is a long time coming. Back in March 2006 I opened a topic stating
that I was getting pools of condensation in my bathroom vent fan. The
fan in question was a Panasonic FV 11VQL3 110 CFM. I tried insulation
aroung the vent pipe - didn't work. Insulation around fan - didn't
work; removed the dampener (flappy thing that does not allow air to
travel back in fan) - didn't work. Finally I took the fan in the
Warranty Shop and they said the Squirrel Cage and motor had to be
replaced. I had high hopes. 3 MONTHS later (due to back order of parts)
I got the fan back installed it and.... same problem.
I called REWilliams.com and they are going to take the fan back. They
were pretty understanding and have a good policy on defective products.
So overall I wanted to say thanks to the people that responded to the
original posting "Condensation inside bathrrom vent fan" and say I am
getting a new fan from Home Depot. Hopefully this one will work. Heck I
might find out that my home has some sort of moisture/venting issue.
Funny thing about this whole experience is that I learned more about
ventalation and fans that I would really care to know.
Also as far as the Panasonic fan, I hear good things about it. Just
cause this one fan did not work for me I am not writing them off. If
there was a place that sold them for 100 bucks like REWilliams.com I
would try another one but all these fan places sell them for $175.
I'm curious, does your vent go through the roof or out the wall. I ask
because I installed a nice older one in our master bath from a
demolition salvage place that removes fixtures from high-end houses,
and I was careful to slope the vent tube down to the wall exit. I've
had no problems
Actually I did a horizontal run of 1.5 feet with a slight slope down
and then it curved up to a vent in the roof. The install instructions
showed that install or a wall exhaust install.
Just to give you a little more information. I actually removed the
dampener and the vent pipe and did a test of running a hot shower and
the fan venting into the attic space. After 8 minutes there was a good
size pool of condensation inside the fan. Got this idea from a few
contractors at church. This test showed that the steam from the
bathroom was not exiting the fan fast enough.
I already have the new fan and plan to install this weekend. I'll let
you know what happens.
Eric in North TX wrote:
I have learned the hard way to avoid metal tubing, it is cold in winter and
can produce a considerable amount of condensation. Now I only use 4" PVC
sewer pipe, it is not as thick walled as drain and vent pipe and has belled
ends for easy connecting. Since I changed I have not had any condensation
problems. Also in my climate and because it runs through the attic I make
sure that it is buried in the insulation for extra insurance, but so was the
metal pipe that gave me problems.
Thanks but I tried everything and I still get a pool of condensation in
the fan. The fan is 110cfm and I only need 80cfm for the size of my
bathroom. Trust me I have been through it all except tearing a huge
hole in my ceiling and roof to allow the steam to vent. ;) Well except
for the PVC idea but the problem is not with the tubing.
Are you sure it is not the tubing, I had water running backwards through the
tubing and dripping out the fan when the fan was turned off. I had so much
water because my tubing ran horizontally through the attic and then turned
up through the roof. This gave about 18" of tubing that I could not get
adequate insulation around. Using the PVC tubing I built a simulated "trap"
at the bottom of the vertical section (and even ran a 1/4" diameter tube
from the trap area to allow me to vacuum the water out of the trap in case
it built up enough to block the airflow, as it did once on one run) to catch
the water and prevent it running back to the fan. I did a lot of crawling
around my attic to correct this problem, even tried an in-line fan near the
end of the run in one bathroom to see if it would help (no difference). My
solution that worked was PVC tubing, piling the insulation over the pipe,
and building traps at the bottom of the short vertical run to catch any
Yep, I am absolutely sure it is not the tubing. I actually removed the
tubing and ran the shower and fan for 8 minutes and condensation built
up in the fan. The fan was venting into the attic for this test.
Also I replaced the fan this weekend with a new one from Home Depot.
It's 110cfm and I am using the exact same materials (tubing and vent)
and I have no condensation in the fan.
I am very excited to have this project done and a working fan.
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