What are good strategies for fitting range hood vent ductwork in tight spaces

Question

As a rookie, I’m not sure what strategies or approaches I should look into to get my range hood vent duct to make the necessary turns in a relatively tight space.

So far, I have

1. the rectangular-to-round range hood outlet piece
2. a 7” to 6” reducer
3. Two 6” adjustable angle pieces

When all combined, I can achieve the necessary ‘turns’ to get it between the wall studs, but it’s way too long/tall: it doesn’t fit within the cabinet. I’d have to cut out most of the cabinet top to allow the ducting to make its way up into the ceiling before exiting out the wall.

Are there products available that help achieve tighter turns? (It’s my understanding that flexible duct is not a safe/approved solution). Do installers modify the products I already have, to make them shorter somehow?

Would most installers simply fabricate their own pieces? (if so, with what? sheet metal and rivets? spot welding?)

Including photo of cabinet space with 12” ruler:

Answer 1

I believe the answer to this question is:

"The correct pieces that you need are likely already available off-the-shelf, but it just takes some shopping-work to find the right combination and you might not find them all at a single store."

It turns out that some home improvement stores carry a fairly limited variety of elbows, connectors, etc. and there will likely be cases where your favorite store doesn't have everything you need.

In my case, I found that all the compatible range hoods and vent boots that they sold sized to 7" round pipe, but all of the applicable wall caps they sold fit to 6" round pipe...this would require a 7"-to-6" adapter somewhere in the ductwork. Also, the same big-name home improvement store did not carry 45-degree angles -- working with 90-degree elbows only significantly increases the overall 'run' of the ductwork.

Ultimately, space-savers I found included:

• A boot that reduced to 6" round pipe right-away. This negated the need for a 7"-to-6" adapter.
• Adjustable 45-degree elbows.
• A little (minimal) work with tin snips to gain a few fractions of an inch here and there.

Answer 2

The 90 degree elbows shown in the picture will rotate on themselves and become 45 or whatever degree bend you want. Then they become much easier to shorten. You can cut them and use a stove pipe crimper tool that will put ridges in the pipe so it can fit into another. I purchased mine a few years back for maybe $20 from the inexpensive tool store, probably 1/2 again as much at azon. I used what is called a reducer; They are not super inexpensive but available online, that will reduce the length by several inches and get it inside the cabinet. A sample picture is included just to get an idea what they look like. As shown this one has some give at the joint. Searching on the web you will find lots of them.

Answer 3

Do you have room above the cabinets to do something like this?