# Island range hoods/vents



## LoneJeeper (Dec 18, 2006)

Gang,

our new house (  ) has an island, with a range/oven in it... and no vents.  I'm noticing that island hoods are expensive and varying. 

What should I look for in a hood?  are there recommendations for kitchen size or   anything?  

Could I get away with a 'bathroom style' vent?

tia,

lj


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## Hube (Dec 18, 2006)

the desired Kitchen exhaust ventilation is approx a minimum 12 air changes per hour(ACH) this is achieved by installing an exhaust hood FAN that is capable of exhausting the entire cubic feet of your Kitchen 12 times in a hour. The fan is rated in cubic feet per minute (CFM)
Eg; a kitchen 12' x12' and  with 8' high walls = 1152 cubic feet (1200 cu ft.)
a fan sized at 240 cfm would exhaust this 1200 cu ft in 5 minutes,or 1 complete air change.
if it ran for the entire 60 minutes it would completely change the air in the kitchen 12 times.

What size is your kitchen?
Note; some  pros suggest the air changes in a kitchen should be even as high as 15 air changes in a hour(ach) 
A lot depends on the kichens layout,etc.


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## LoneJeeper (Dec 19, 2006)

good info there, thanks Hube.

lj


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## glennjanie (Dec 19, 2006)

Please consider this; there has to be air comming in from somewhere in order to exhaust that much air. You said it is a new house, which is normally tightly sealed, I would suggest an 8" make-up air duct to feed the exhaust fan. The make-up air duct can be dampered and regulated to limit the rush of cold air and there are heat exchangers on the market to economize on the lost heat. Or, you could run the make-up air into the return air duct to come through the heating system which would call for a considerable up-sizing of the heating system. Just some thoughts that go along with exhaust air.
Glenn


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## LoneJeeper (Dec 19, 2006)

interesting... that adds a bit to the total cost of a hood, that's for sure.

How would you damper and regulate the 'make-up' duct?  Would it have a fan as well, or just rely on the difference in air pressure?

do you think i could make it suck a certain cat into the stratosphere?


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## Square Eye (Dec 19, 2006)

Buy one with a Hemi on it LJ!
You'll hear a certain wooshing sound around all of your windows and doors, but your cat will be gone for good.
Use the throttle for a damper.
Will displace all of the air in your house in less than a second


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## LoneJeeper (Dec 19, 2006)

hm... i wonder if hemi's have a cats/gallon measurement.

yeah right, even if it was 0.00001   it'd still be worth it.


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## glennjanie (Dec 19, 2006)

Use round metal duct with an internal damper (a round piece of metal that is almost as big as the duct, with an external handle on it). No, a fan is not necessary for the make-up. AprilAire.com makes an air exchange unit called PerfectAire; its worth checking out.
Glenn


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## Hube (Dec 20, 2006)

The average built home of to-day would still provide enough infiltration to provide sufficient air flow for the average kitchen exhaust fan. 
An exhaust fan run for a short time to exhaust kitchen odors, etc would create no problem.
However, if you are planning to run this fan several hours in a day, yes without make- up air there could be a "negative " pressure created within the home.
One way to prevent this negativity to happen would be to install a HRV or ERV system which will bring in fresh air and expel any stale and moist air. This type of system can be set up with an air measuring instrument (magnehelic) and also will reclaim most of the heat from any stale air that is expelled and this heat can be put  back into the home . This is especially efficient for those cold winter months.
Another inexpensive way to provide "make-up air" (if it's needed) is to install a "ventamatic damper". It has a screened intake with a flapper that only opens when it is "drawn" open by the operation of the kitchen fan.It is gravity operated, no electric power needed.this type of damper can be placed anywhere within the home.


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## Daryl in Nanoose (Dec 24, 2006)

LoneJeeper said:


> Gang,
> 
> our new house (  ) has an island, with a range/oven in it... and no vents.  I'm noticing that island hoods are expensive and varying.
> 
> ...



Are you sure there is not a Downdraft vent system.  My last stove had one so I was just curious.


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## LoneJeeper (Jan 8, 2007)

when we first looked at the place we thought the stove had a downdraft vent, but it doesn't...


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