New Kitchens / Remodels

[j44ke]

What Brian says.

If you do horizontal, there should be a calculation for the blower for length/diameter of pipe and vertical/horizontal travel. If the blower is under-powered, then you may end up with accumulation of stuff inside the pipe and/or cooking smells in each room the pipe travels through. If your installer can't answer that question, then the manufacturer of the hood should be able to.

Installers would rather run it out the side of the house so they don't get blamed for roof leaks. So if your installer seems hesitant about running it vertically, that might be a sign to involve a roof contractor to do the hole, shingles and flashing. Or find someone else who can do the install you want.

[Tom]

Shortest distance, least temperature contrast if you can make it work unless with horizontal the push is such that it is in there without any time to cool off.

[caleb]

Shortest distance, least temperature contrast if you can make it work unless with horizontal the push is such that it is in there without any time to cool off.

Hmm, the vertical run would go through 2-3' of unheated attic before the roof. Going horizontal would keep it heated right to the exterior wall.

[j44ke]

Go for most vertical fewest corners shortest distance stablest temp. So wrap a vertical vent if it goes through unheated space.

[caleb]

Go for most vertical fewest corners shortest distance stablest temp. So wrap a vertical vent if it goes through unheated space.

Thanks, Jorn. I think I remember @thollandpe advising something similar to another user long ago.

I talked with the installer last night, and he said he was fine talking through it on Friday when they come to do the work.

[thollandpe]

@caleb, the fan has to push against the friction of the duct, and it makes no difference whether the duct is horizontal or vertical. It's just the total length plus the resistance of all the fittings added together. Size (and velocity) will have a big effect on pressure drop too. Commercial kitchen exhaust ducts used to be designed for fairly high velocity, 1500 fpm, to keep aerosols suspended. But the minimum has been dropped to 500 fpm in recent history because it results in less grease accumulation.

It doesn't sound like either of your options is going to have a significant length or a bunch of fittings. Regardless of routing, I'd make sure they plan to use rigid duct, and not flex like below.

The rigid duct should be straight and not have a belly in it to collect moisture. The duct in my house is horizontal, rectangular, aluminum, and has been AOK since 1978. Don't worry about going out the sidewall of the house.

If it's running through an unconditioned space you should insulate it so it won't condense once it warms up. If it's running through a conditioned space make sure you have a backdraft damper to keep it from condensing on the outer surface when off in cold weather. They also work well to keep wrens out.

And I'll repeat a warning. If your fan has a large exhaust air volume, like more than 400 cfm*, give some consideration as to where the makeup air will be pulled from. You don't want it supplied through your dryer vent, bathroom exhaust fan, or flue (especially for a gas-fired appliance).



* Full-on commercial kitchen hoods for appliances like char-broilers and deep-fat fryers will be designed for 240-360 cfm per linear foot.

[rwsaunders]

I had to run my kitchen exhaust hood duct through the wall like Professor Holland did and it’s been fine for 23 years. Running it through the roof would have been a major event…two story home.

[caleb]

Thanks for the clarifications, @thollandpe and @rwsaunders. Good to know that vertical routing is not essential, but rigid venting is. Looking forward to getting this done tomorrow.

[rwsaunders]

See if you can find a vent with a magnetic flapper too. I have a rectangular unit like the ones in the link that I’m very happy with…bird/insect screen and magnetic flapper.

https://www.luxurymetals.com/range_h...tml#anchor_955

[caleb]

Thanks for all of the advice on the hood install.

I had previously been talking to an estimator, and the actual installer understood my concerns right away.

He ended up going four feet horizontally with rigid duct, and insulating the run through the pantry. The insulation wasn't so much a ventilation issue, but an easy measure to avoid throwing heat into the pantry and rotting the potatoes. I'm glad he foresaw that issue.

Turns out the stucco on the wall of the house is 3"+ thick, and getting it cut right was something of a process. It took him most of two days start to finish, and I'm sure glad I didn't try to DIY it.

[sbornia]

Hey, the recent posts above about 30" gas ranges are very timely since our nearly 30 year-old Wolf is showing its age more than usual these days. I may track down replacement ignitors for it and already know the right local guy to help install them...but it will still be an old stove and I may want greater peace of mind.

So I started looking at new gas ranges, and one consideration I've already discovered is that our countertops by the current stove are 37.5" high:



This seems about 1/2" - 1"+ higher than some gas ranges can be adjusted in height. For example, the very nice Thermador 30" I saw today tops out at 36.75" high, and the modern Wolf 30" is spec'd at 36" high.

Ideally of course we'd be able to maintain the currently flush level between our range and countertop. I'm wondering if there are workarounds to this issue that don't inadvertently compromise safety. For example, to raise the surface on which the range sits, could I place on our hardwood floor a 1/2" thick slab of wood or stone cut to 30" by 22" and then install the new range on top of that? If done right, this might almost be unseen unless you bend down to look under the oven.

Or am I overthinking this and is there a more elegant way to extend the height adjustability of gas ranges without creating a tipping hazard?