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I have an existing ductless range hood that I want to replace with a new, ducted hood. Fortunately the attic above my kitchen stove is cavernous and easy to run 6" ducting through to vent through an exterior wall (probably less effery with waterproofing than going straight up through the roof).

While I have the skills to do this myself, I'd rather pay a contractor to do it than spend a week picking fiberglass out of my skin and coughing my lungs up from my allergies to the dust in that attic. I learned that lesson the last time I ran something up there. A week of misery isn't worth it to save a little cash I can easily afford.

Would I just go through my usual HVAC contractor, or is there some oddball specialized contractor that I'm not thinking of?

I have an existing ductless range hood that I want to replace with a new, ducted hood. Fortunately the attic above my kitchen stove is cavernous and easy to run 6" ducting through to vent through an exterior wall (probably less effery with waterproofing than going straight up through the roof). While I have the skills to do this myself, I'd rather pay a contractor to do it than spend a week picking fiberglass out of my skin and coughing my lungs up from my allergies to the dust in that attic. I learned that lesson the last time I ran something up there. A week of misery isn't worth it to save a little cash I can easily afford. Would I just go through my usual HVAC contractor, or is there some oddball specialized contractor that I'm not thinking of?

(post is archived)

[–] • 1 pt

Are you venting into house or outside. Your description makes it simple over engineered. Installed plenty as electrical man and all of that attic shit even in new houses no way man that's way over the top stuff. Most use 3 inch duct work and go straight out hood to outside house so only a flap cover and small duct pipe is required you asking for fancy shit

[–] • 1 pt

Venting outside. 780 CFM max for the hood, though realistically I shouldnt need to crank it past 550-600 CFM for my stove. That's why I was leaning towards 6" ducting rather than 3-4" ducting you might use with dinky sub 300 CFM hoods.

The current hood is ductless and mounted on an internal wall, so I dont have the easy option of venting directly out through an external wall. I have to run some kind of ducting through my attic to install a ducted hood.

[–] • 1 pt

Erm that sucks Architecture designed. In that case still don't need 6 inch. For such a long run I would recommend 3 or 4 inch to maintain pressure. Remember a 90 breaks pressure in half to regain that your straight is 10 times length of 90.

[–] • 1 pt

Don’t do 3”
6-8 is what I’m normally installing your probably going to have to work with an electrician and a hvac guy . Possibly a carpenter to finish the exterior. Honestly the whole thing is a fucking hassle and nobody wants to take responsibility for an entire job even if it’s just a range vent and by time you pay for three professionals to each of there part you’re going to be into it for close to 1,000 when just a few years ago you could get it professionally done by one man for 150 bucks and he would have been happy to get it. ………… sorry I’ve been drinking dm me with a general location and I’ll see if I can make it 🥴

[–] • 0 pt

Thanks for checking my logic on 6" ducting. $1000 was around the ballpark I was guestimating based on the hassle factor.

At least the electrical's already run for the existing shitty hood, so that'll be a piece of cake.

[–] • 0 pt

That's a bit more CFM than an average domestic hood.

Check the manufacturers literature or post the make and model number here. It should give you duct size, max length, and maximum equivalent length ( total length plus equivalent length for elbows and termination)

8" might be better for noise and performance, especially if you're going to crank it to max at times.

Definitely not 4". That'd be ridiculous.

If you have any gas fireplaces, atmospheric vented gas water heater, wood stoves, or others you'll need to look at makeup air.

[–] • 0 pt

Ill do it for a six pack of beer and some tacos. Come to think of it, so will the mexicans outside of homedepot. I wont burn your house down wiring it up though.

[–] • 0 pt

It's an appliance.

Appliance repair/install business will assist you.

[–] • 1 pt

They'll install hoods, but I'd be surprised if they want to dick around with running ducts. Am I mistaken?

[–] • 0 pt

They'll sub it out to someone who can.

[–] • 0 pt (edited )

Usually you want to run the 3x10 rectangular duct work. This fits neatly in the walls between 2x4 studs and both the standard intake and exhaust for the range hood tend to assume this size. I don't believe you can use any flexible duct work on the kitchen hood because of the grease buildup. Any hvac guy should be able to do this for you, but in general they hate working with the rigid ducts these days. If you already have an HVAC guy then call them first. If you get a lot of push back then find someone more willing to do the work.

Before you start you should see if the hood will be placed in the center between two studs (best case). I think you need to tear up the wall and frame it out like a window if there is a stud running right in the middle. You don't have to run the ducting through the wall. It can run through the cabinets. Also, I think there are some code requirements (like adding straps or something) if they run through the wall and cut the sill plate at the top in the attic. These kind of complications are why a simple few feet of ducting gets shockingly expensive and lots of HVAC guys avoid doing it.

[–] • 1 pt

Yeah, I'd have to use rigid ducting for the reason you mentioned. Flexible ducting + grease is bad times.

Due to idiosyncracies of my kitchen, it's a whole lot easier to use a wall mounted hood and run ducting directly up through the ceiling than dick around with rectangular ducting between studs. If there was a finished room above the kitchen, ducting between studs would definitely be the way to go. Since it's just a cavern of an attic, it's waaay easier to just duct through an attic and out through a wall.