Terry wrote:
>
> Gentlefolk,
>
> One stove vent actually vents to the outside. There's a couple of
> semicircular metal flaps at the bottom of the ductwork that seal it
> off when the fan is off, but they flip up when enough pressure has
> been built up from below, opening the vent and letting the nasty fumes
> out.
>
> Problem is that the flaps and the ductwork are greasy and tend to
> stick in the 'up' position. It's not much trouble in the summer, but
> in the winter, cold air pours in from the outside. I take off the
> aluminum filter, then pick and pry with a pancake flipper until the
> errant flap comes down.
>
> I attempted to clean 'em with degreaser but it's pretty hard to reach
> up there. I'd really rather not take down the entire vent from its
> ducting if there's a better way. Any ideas?
>
> Best -- Terry

First line of attack to resolve the problem is to eliminate the sources
of "nasty fumes", it's a kitchen stove vent hood, not a vent hood in
some nasty chemical plant

The only way I can think of to clean it without taking it apart, and
they way the commercial ones are often cleaned, is with steam. If you
get one of the consumer steam cleaners, some plastic drop cloths and
masking tape to contain the run off and a case of paper towels to soak
up the run off, you should be able to clean them reasonably well.