# Forum Home Renovation Electrical  Rangehood ducting  best method and also where to purchase from?

## Williamstown

Our range hood is currently venting into the cupboard which it is installed (previous owners!)  basically does nothing.  I want to get it ducted obviously out of the cupboard and out the roof, rather than into the roof space, which is just as bad as the cupboard. 
We have high ceilings and therefore the cupboards dont go all the way to the ceiling so there is a 500mm gap between the top of the cupboards and the ceiling.  The wall backs onto another room so I cant vent it without going straight up. As I dont really want to fill the void above the cupboards, the ducting will need to look decent. 
Im after ducting to run from the range hood in the cupboard, from the top of the cupboard to the ceiling (will be visible so needs to look ok) then into the ceiling and out the roof.  Are there kits that are attractive, or alternatively do I use something like the following and somehow try to box it (not idea as it will look odd) or get some SS flashing made to cover it?  http://www.jpmark.com.au/index.php?m...548031867-4775 
I can post photos if it helps? 
Any opinions would be appreciated also difficulty of installation (which I assume is quite straight forward).
Regards, Darren

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## Gooner

Personally I would use a kit similar to the one you have on your link. They sell these types of kits at Bunnings for around $100. May need to buy an adapter from your rangehood to the expandable flue. 
I would then try and find a way to make a nice cover for the space between the top of the cupboard and ceiling. I guess it depends on what look you are after.

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## seriph1

50mm is a tiny gap between cabinets and ceiling  -  do you mean 50CMs? Take a pic or two of the wall showing all cabinets etc. and we can have a look.

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## AIRMAN

If you want maximum airflow from your range hood it is best to use a ducting with a smooth straight inside, flexible ducting causes yurbulance in the air, builds up pressure and reduces the airflow. 
In you situation you could use a piece of 100mm pvc straight up in to the roof and the use elbows and more straight to get you to the eave and attach a plastic grille. Or you could use the semi rigid for the whole thing. You should only use flexible duct as a last resort when you have to go through some tights places or lots of bends. 
As for covering it up I would just get a peice of hat sections folded up at a local sheet shop out of thin gauge stainless, or colour bond if it suits your decor better.

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## Williamstown

HI All,
Thanks for the replies.  Yes you are correct it is 500mm (50cm) to the ceilings.  Thanks for the point about not using flexible ducting as that is what i was planning on using.

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## woodbe

I don't have any photos, but we had ours done in galv pipe supplied by the appliance shop. Our range hood also came with an option of an extended trim kit to hide the pipe in SS. It's basically a 'D' profile Tube in stainless about 250mm wide to match the range hood. Looks great and works a charm. There is a louvre flap affair over the end of the pipe on the outside wall. 
The brand of the range hood is 'Smeg' I expect other brands would have flue trim kits. 
woodbe.

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## Metung

I was going to use PVC pipe for my range hood but the bloke at the plumbing supply shop said that it was against the rules. I couldn't understand why since the connection for the flue on the range hood was made of plastic. Maybe somebody knows if this is correct or not.

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## Uncle Bob

I reckon your on the right track. I would be using stainless steel on the visable part at least. Your local sheetmetal fabricator will be able to knock it up for you, they may even have some in stock.

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## Uncle Bob

> I was going to use PVC pipe for my range hood but the bloke at the plumbing supply shop said that it was against the rules. I couldn't understand why since the connection for the flue on the range hood was made of plastic. Maybe somebody knows if this is correct or not.

  I suppose the problem with using PVC pipe is the melting factor, though I have seen it done before. You wouldn't want a stove top fire though.

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## tricky4000

I installed mine with flex aluminium duct...true not the best but I had a few tight curves.  Ideally you'd pick up some galv 150mm pipe (assuming 150mm is your exhaust out) and then cover.  PVC is illegal in this application (in VIC as far as i am aware anyway).  You may choose to cover with the D profile stainless device or simply box it in with some timber studs, a bit of plaster, a touch of paint and she's all done.

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## AIRMAN

If pvc is illegal then flexible duct must also be because it is made from plastic, I guess you have to use semi rigid aluminium or galv.

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## Uncle Bob

You can get flexi duct that's made from aluminium, it concertinas.

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## woodbe

We used Galv pipe. You can get all sorts of angle joiners for it. 
And yes, the flippin' range hood has plastic joiner bits in the pipe. Maybe they are special fireproof plastic, but they sure looked like recycled icecream containers. :Yikes2: 
If you use straightwalled pipe the resistance is less than flexi. I wouldn't use PVC in there even if it was allowed. 
woodbe

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## AIRMAN

Flexible duct is made from metallized plastic unless a few companies sell a aluminum version but it isn't very common, alot of the look like aluminum but are in fact metallized plastic. This stuff is only rated generally to about 70 degrees. 
Semi ridgid duct is the stuff made from soft aluminum.

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## Uncle Bob

Ok, the flexi-duct we're thinking of must be the semi-ridgid stuff, as it's definitely make of ali.

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## Pulse

I used 100mm PVC with no trouble. The rangehood is made of plastic so is the PVC pipe melts the rest of the kitchen would probably have to be on fire already... 
Cheers
Pulse

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## bcaso

I did some research and in VIC anything but some sort of metal is illegal and insurance will be void if a claim is made.  I have just ran some aluminium flexi duct from bunnies and tried to straighten out as much as I could, have ran it to the outside under the eves. 
Not sure how noisy its gonna be and how much buildup of grime at the vent. 
Anyone experience any grime or backdraft on a windy day???

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## Uncle Bob

You can get a backdraft prevention grill. It has shutters on it so the air only flows one way.

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## wozzzzza

well i just did my rangehood, i was looking around and was stuffed if i was gonna pay over $100 for a flu kit so i made my own from galvanised stormwater pipe from mitre10 and a cowl from bunnings all up for $28.  just dont get a cowl from mitre10, they are the biggest ripoff.

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## tricky4000

It looks very much like aliminium to me.

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## Williamstown

I ended up purchasing a bunnings extraction kit (forget the brand) for $105.  Apart from cutting a hold in the corrogated metal and a plaster support being in the the way of where I wanted the flexduc it was all pretty simple.  Just need to box it in to cover up the flexduct this weekend.

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## bcaso

please let us know how noisy it is.

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## Williamstown

Its not noisy at all (it is only ducting, etc - no extraction motor apart from the ranghood itself). Infact the unit itself is quietier now that most of the sound beforehand was from the poor extraction/connections.

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