Thank you!

In your opinion, do you think screw insert to the framing on two each side ( given that the framing is attached to the wall studs securely )are enough? the insert is 46 3/8" wide and 22 1/2" deep. I've watched lots of installation from big box insert hoods and I feel like there are more than four screws to secure them, or they have a lips or mounting brackets.. Am I over thinking here?

Just heard from MA and they indeed recommend the screw into the stus in the wall through the back of the liner. MYSTERY solved!

Thank you, Kaseki. you've been really sweet :)

I have no input on the insert, but just wanted to say that I ordered a full hood from Modern-aire in my previous house and was very happy with the product while we lived there. I even visited their office/factory in LA with my kitchen designer to look at all their finish options.

It is hard to evaluate what screws inserted into what surfaces are adequate when I don't even have the weight of the unit to work with. There is always a screw that will hold some given weight in shear, and some screw that will hold without bending or ripping some weight in tension. There is usually some screw that will do both.

Are these screw holes at the back of the insert? Do they fit nicely with the positions of your studs? Alternatively, are you supposed to attach horizontal wood lengths (cleats) between (and past) the studs and screw the insert to them (for inconveniently located studs)?

There isn't any screw hole at the back of the insert, only two at the each sides and that is it! Neither called out to install with cleat. I think MA kind of left it up to the installer which is bit frustrating. The wall is covered but I don't mind open it up and adding few blocks if needed. This is why I have been struggling how I'm going to install this. I have done some woodowrking/ simple framings work throughout the house so I know it need to be on pretty secure. ( I'd say 70lbs?? best gestimate. It just a shell since I'm doing inline motor.)

This is what I received from MA rep.

" The installer should screw into the studs in the wall through the back of the liner. We recommend lagging every 4-6 inches vertically."

Now that I know I can drive holes on the back, I need to think about best way to mount this. I can do french cleat if this is the most secure way. What drill would you use to drill thick stainles steel?

By the way, just found out that Fantech will have Make up air unitary kit coming out soon. This has most of components within a box and was told that a silencer won't be necessary. Their modular system requres about 10ft long clearance so this new unitary kit will save the space and installation cost as well. Sometimes it pays to be a procrastintor. :)

Assuming that the liner has the correct front-back alignment at the bottom when the back is screwed to the wall (otherwise you will have to space it out) drill holes where the studs actually are when the liner is properly aligned with the cooktop. Every 4-6 inches doesn't tell me how many will fit in the height of the liner, but I will guess you could fit 4 or 5 on each side.

I'd use stainless steel screws. For total corrosion resistance, 316 SS will do. Simpson makes some flat head, spline drive, number 14 x 3.5", as I recall. About 80 cents each. More than enough shear strength. Wall should be flat. The screws will probably dimple the liner and wall when torqued tight.

Actually drilling the back will be annoying. Carbide drill bits will be useful, but a drill press may be needed to keep from breaking them. You could take the unit to a sheet metal fab shop, and let them drill at your marked locations.

You can't just hang the insert from a French cleat. You could use one to hold the liner in place while you attach the liner firmly by using screws through the back, through spacers or plain cleats, and into the wall.

Urghhh... I'm starting to regret that I've got MA.. I'm sure it is all worth it if you getting the cover ( some of images I've seen.. they are gorgeous )but if I had to do it again, I wouldn't get this model. I like the idea of taking the hood to local metalsmith. Stainless steel being very hard, I'll or any installer with drill bit will surely make a dent. or I can take it to their office ( I'm local )and see if they can do for me for a fee.

• Look at the page 4 of the instructions for the Trade-wind VSL. Note that NO holes are pre-drilled to hold the insert in place and a titanium bit is required to cut them. Ugh but...
• Look at page 14, step 3 of the instructions for the GE Profile. Note that screws are inserted horizontally from the inside-front and -sides of the hood into the surrounding cabinet to hold it in place. For this model, there are no screws at the back.
• Look at page 14, figure C of the instructions for the Zephyr. Like the GE Profile, screws are inserted horizontally into the surrounding cabinet.

Based on this, I would say that you have to construct a cabinet whose cutout is length "A" and width "B" with sides around the cutout at least 3" high (as shown in the specs). You'll then run screws through the inside-front and inside-sides of the hood through holes you drilled in the insert into the 3"-high wood.

As Modern-Aire recommended additional screws into studs behind the insert, I suppose you could add those too though the other brands' inserts don't use them.

This is so helpful. THANK YOU!

MA rep did tell me that the same reason why there isn't any pilot holes on the back ( since everyone's studs place wil be varies ) With these two installation manuals, I think I can make it! work.

The GE Profile installation instructions reference screws A, D, and L on page 11 for attaching the hood to the cabinet. You could use one or more of these screw sizes (e.g., short screws for the front, longer for the sides) otherwise you might be at the hardware store saying "hmmm" to yourself as you stand in front of packages of 1,000 different size screws.

I love it! Yes, knowing exactly what screws to use is really helpful as well. I need to go back read further but either ones from your original post also specified recommendation on the roof cap-- which I needed, and the kinds that they don't recommend. I believe that both insturction manual are fairly univeral that I can apply for my installation. Thanks again!!! I'll give it a go over the long weekends( to just build a box frame for now as a mock up )