# Large vent hoods



## donttellthewife (Mar 26, 2008)

This is my first post here, so hello to everyone and I'll introduce myself

I had been installing appliance for about 15 years for a large retailer in the Portland OR area, up until last year when I knew that the back wasn't going to last much longer. Now I sub out to a general contrator doing different aspects of home remodeling that my license will allow me to do. 

The question,
I have a customer that wants a 42inch wide Vent A Hood brand rangehood  installed over her new Viking 36inch range. I have never installed this brand of hood before and can find nothing as far as a review is concerned about quality. From what I have found from the companys website and google searches I not impressed.
This vent is rated for 900 cfm and has two outlets that combine back together above the unit into a 12inch round vent, PITA. The model number of this monster is PRH18-342 SS. If anyone has had any experiance with this hood or can steer me in the right direction of a unbiased review I would be greatful.

Thanks, Ron


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## Michael Thomas (Mar 26, 2008)

Vent A Hood is a well know brand, you see them often in custom kitchens.

Two things to keep in mind:

1) On the dual-blower units, it's normal for the fans to be considerably quieter when both are running - customers often think this is the result of a defective unit.

2) Especially in a small and/or tight houses, test for of backdrafting of furnaces, WHs ect. when the hood is running.


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## donttellthewife (Dec 27, 2008)

..........


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## pderas (Mar 1, 2009)

_Vent-a-Hood IS a well known brand and a high-end product.

Read the installation instructions.

Take care in installing it because the owners paid a steep  price for it.

Don't downsize that 12" round vent or you will create problems with turbulence and excessive noise.

Use smooth, metal vent pipes. 

Make only 45 degree turns, with some space between to cut turbulence.

I always specify that hood vent pipes be well supported and insulated to dampen vibration and keep the system as quiet as possible.

The negative about Vent-a-Hoods is that they don't have a rheostat switch. They are either on or off (in this case 1/2-on or all-on since there are separate switches for each blower). I have specified that a rheostat be added but it negates the warranty.

I prefer that my clients have a hood they will use rather than one the won't because it's too noisy. That's why I am so fussy about how they are installed.

Vent-a-Hood's philosophy is that THEY know best and the customer can't be trusted to judge what's best in their own kitchen.

Aside from that it's a great product._


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## fuster (Mar 30, 2009)

Vent a  Hood is supposed to be quiet.  The advertising is somewhat misleading, IMO.  

DCS makes a hood with better baffles and will suck the chrome off a bumper.  They have a four speed controller.  They are made in Italy.  They cost a bundle but if your client has a Viking range, they are used to paying a lot for appliances. 

I have a DCS hood, sorry I can't comment on the Vent a Hood other than to say we first wanted a Vent a Hood, and the dealers who sold DCS also sold Vent a Hood and the consensus seemed to be that if you can afford it, the DCS was the best product because of their baffles.  I do not think it is too noisy, I use it on all speed settings.  If you want to listen to the news while you cook with it, well I think maybe you should hire a cook and sit closer to the TV.


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## pderas (Mar 30, 2009)

You will find that ANY quality hood, unconnected to venting pipes, is quiet. Dead quiet.

It is the installation that separates a quiet hood from a noisy one in practical application.

Installers use all kinds of piping material. They go from round to 3-14x10. They use flex pipe. They put in whatever 90 degree angles it takes to get the air from point A to point B. All of the above contribute to vibration and noise and homeowner unhappiness with their hoods.

As a kitchen designer I have been dealing with this problem my entire career. I'm just trying to point out that an extra hour taken in properly installing the vent pipes and insulating them to dampen vibration will result in many years of happy-hood-using for the homeowner.

Unfortunately the hood manufacturers don't emphasize, or sometimes even advise, these measures. That's why I'm doing it here. To create happy hood owners.


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## Quattro (Mar 31, 2009)

Thanks for the advice, pderas.

I'm about to install a hood from Euro-Kitchens, and I'm wondering about piping and insulation. The hood came with 3 or 4 feet of the semi-rigid flex (6" round) with two ABS fittings for either end. I suspect I'll use that to get to the attic, then route hard steel vent pipe to the roof jack...all in 6". But, how do I insulate this? Is there a special kind that you recommend? And, how do I seal the junction of the pipe and the ceiling? I suspect much of the noise from vibration happens at that juncture.

Thanks


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## pderas (Mar 31, 2009)

I strongly suggest you discard the flex and use rigid 6" pipe all the way. 
Try to make only 45 degree turns with a foot or more of straight pipe in between.
If you HAVE to make a 90, use two 45s.
Pack and tape fiberglass insulation around the pipe after it is all assembled and the seams sealed with UL181-approved water-based mastic (NOT duct tape. You can use that to tape on the insulation if you like)(CA Title 24), or whatever your building department requires. Or you can use spray foam. Any insulation material that will keep the metal from vibrating as the air rushes through.

Fasten the ductwork to the structure around it to further dampen vibration. Ductwork hanging from the roof cap will vibrate a lot more than if you add a couple of 2x4s to support it.

Do all that and your hood will be a marvel of quiet. You'll actually USE it, and all your guests will be amazed!


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