Outside winter temperature often reached -30 C. The fresh air intake iced up
resulting in furnace shut down. The furnace is 1 year old, high efficiency,
forced air furnace.
The intake is a 2.5" OD black PVC pipe.
The cloth dryer's exhaust vent is about 6' below and 3' displaced from the
furnace air intake.
Other than moving the clothing exhaust vent elsewhere, any suggestion to
avoid having to remove the loose ice from the air intake?
No problem when the cloth dryer is not running.
Heat it? You can get electrical pipe heating tape to prevent outside pipes
... but I don't know if they are powerful enough.
...check it's rated for outdoor/wet use
My first thought is that you should consider whether it is possible to
recycle the dryer exhaust and use that heat (and moisture) in the
Other than that, extend the dryer exhaust above the furnace intake, or
more the furnace intake down below the drier?
The point is that the dryer vent is exhausting warm, moist air; as the
exhaust cools to ambient below freezing temperature, some of the
moisture condenses out and freezes. Since this is all happening near
the furnace intake, some of that ice ends up at the furnace intake
vent or in the intake pipe; over time it can build up and restrict the
pipe enough to cause a problem.
on 9/4/2007 12:19 PM Wayne Whitney said the following:
I'm still at a loss.
Shouldn't the clothes dryer have an exhaust vent to the outside? Is it
exhausting into the room?
Is this the same guy that's over in alt.home.repair that complains of
having to clean lint out of his bathroom fan once a month? :-)
I seem to get two suggestions so far:
1) Heat traced it.
2) Heat trace not suitable because the pipe is plastic.
a) How hot can the heat trace wire get to? Can the PVC pipe (the kind one
can buy from any construction outfit) take the heat safely?
b) If it is safe, how shall one proceed to heat trace it. The loose ice
accumulates near the entrance grill only. The body of the pipe is never
plug. It is the accumulation of loose ice from the moisture of the dryer
vent at the intake grill that will eventually restrict the air intake so
much that the safety mechanism of the furnace shuts down the heating cycle.
Thanks in advance,
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If you paid to have the furnace installed, contact the seller and ask him to
make the necessary changes (I believe that you are supposed to maintain 6'
from a dryer exhaust for just this problem). If not, it appears you have two
choices. One is to install an elbow and run the intake to a higher level.
The second is to close off the existing inlet and route a new one to a
different location. (Or perhaps you could reroute the dryer. But do not
terminate the dryer exhaust inside the home. The additional moister load
will cause untold problems inside the walls.)
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