On Thu, 21 Jun 2007 20:17:03 -0400, "CompleteNewb"
wrote:

We have a house with very steeply sloping roof (2nd floor rooms have that
slanting ceiling on both sides, if that tells you anything). The kitchen is
on the 1st floor, so please keep reading.

I fry and sear a lot in the kitchen when cooking, so every kitchen surface
gets coated with that nasty, greasy residue. So, my plan is to install a
hood over the stove. The problem (or so people have told me) is that the
hood exhaust needs to stay straight all the way to the outside of the house;
no elbows.

Unfortunately, the stove is on the wrong side of the kitchen; the stove is
against the wall that's leading to the inside of the house, not against the
wall that's the outside of the house. SO, if my hood exhaust goes straight
up with no elbows, it will need to got through the 1st floor ceiling, then
the "cubby space" (behind the little straight wall ofupstairs, where you can
see rafters) of the 2nd floor, and up through the roof of the house about
haflway down the roof as seen from outside.

My hope was, rather than getting up in all that cubby nonsense, maybe I
could elbow the exhaust as soon as it breaks into the ceiling of the
kitchen, go about 5' laterally (horizontally, along the ceiling, the width
of the kitchen), elbow again to go up, and come out through the roof on the
other side of the kitchen (avoiding cutting through floor of upstairs cubby
AND roof of upstairs cubby), which would have the exhaust coming out near
the rain gutter on the outside of the roof.

Several people have told me that kitchen hoods should NOT have ANY elbows,
should be a straight shot from stove up to outside. My plan has 2 (count
'em, two) elbows.

Are the people that have advised me right (they are not necessarily
contractors, they are just general handymen)? Will a hood not work well w/
2 elbows in the exhaust? If I used 2 elbows, would I need additional fans
at every elbow to help exhaust? Or would the fans not even help? OR, would
having the 2 additional fans be more complicated than just running straight
up through the ceiling/floor? Or am I thinking incorrectly that my plan
saves some work, and it would actually be EASIER to go through everything
going straight up?

Any advice appreciated. I realize a good solution would be to stop frying
all the time, but I'm one of those "die happy" types.

Thanks for reading, and in advance for any opinions, advice, etc.

A Complete Newb (and first-time homeowner)


The longer the run and the more turns, the greater the turbulence and
less air flow. Plus, you may lose cabinet space. Ideally, moving the
stove to an outside wall is the solution. But that may not be
practical nor cost effective. You can...

Install a hood fan that will move more air; ie, has a higher cfm. The
tradeoff here is that a more powerful fan produces more noise, so get
a fan that has several speeds. Panasonic makes powerful exhaust fans
that are less noisy, but they cost a little (30%) more.

Use larger diameter piping. The larger cross-sectional area will
allow more air flow. The downside is that you need more space to
install it. The piping must be sealed properly, else you may lose air
flow, perhaps equivalent to adding another elbow.

Avoid putting a pipe though the roof, if at all possible.