I have seen several discussions on the dilemma of having a stove top located in an island, and needing the proper ventilation.
I’m considering a custom made hood, but like others, don’t want the hood to obstruct the view in the kitchen. Down draft really isn’t an option, and the reviews don’t appear favorable anyway. We are installing an electric cook top. What I am wondering is; does anyone have experience with install a 600 cfm exhaust, but raise the height above the recommended 30″ maximum above the cook top.
My thought is to go with raising the hood. Some say many homes aren’t installing fans at all, and I figure a fan installed higher as got to better than no fan at all.
Any help is appreciated.
Mic.
Replies
We just went through this at a small reno and had to put a makeup air unit. Complete with intake fan, duct heater, damper motor and duct sensors because 500 cfm was definately going to cause a negative pressure in their home!
Beleive me it got expensive fast.
bake
Edited 12/14/2003 1:19:01 AM ET by bake
"We just went through this at a small reno and had to put a makeup air unit."
I wonder if the ideal situation would be to have the incoming air provide the combustion air for the stove/range? Then you wouldn't be pulling a cold draft in somewhere else in the house.
Don't know how possible this is - It was just a thought.Happiness is having a large, loving, caring, close-knit family. In another city.
I went with a down draft in my personal home. 6" duct. Works OK for us.
If you do go with a 600 CFM hood, I'd check clostly on the noise level. You wouldn't want the environment in your kitchen to resemble a aircraft landing strip.. ;^)
The makeup air question rasied above is a valid concern too.
>> You wouldn't want the environment in your kitchen to resemble a aircraft landing strip.
Not as a first choice, no. But it might be better than having it resemble an oil fire in a butcher shop.
Not sure I get your point...
Matt
A hood or downdraft ventilator that is acceptably quiet may not have enough capacity to handle the smoke / steam / odors from the dishes you like to cook. Thus the reference to the smell of seared meat and cooking oil smoke.
Yes, but 600 CFM? I understand the origional poster's reasoning of using a higher powered blower at a greater distance from the cooking surface. Perhaps the above sugestion of the a remote mounted blower would be the ticket. The thing is that if it were a very loud exaust fan, it would probably end up being used less frequently. Even a 200 CFM kitchen fan running on high can be a bit loud.
One of the basic concepts of building tigther, more efficeint homes is to supply controled ventilation, especially at moisture "point load" areas such as kitchen and baths. In stalling a fan that won't be used on a regular basis is not wise. Matt
I'm not trying to be dogmatic. It really is a matter of balancing different factors. How loud is too loud? How often do you cook really smoky things? Would you have to modify your heating system to heat makeup air fast enough to avoid cooling the house in winter? Etc.
Maybe a multi-speed fan is the answer, but at what cost in added complexity? Maybe it would be less hassle overall to omit the kitchen ventilation and just scrub the kitchen from the top to bottom every few years. Or if you're going to make authentic Chinese stir fries in a really hot wok, maybe it would be better to only do that when it's warm enough to do it outside.
As far as I know, most kitchen exhaust setups are multi speed. Really, though, we are just discussing possibilities. I guess in summary 2 points I was making, was if going with a high CFM setup, give the amount of noise generated some forethought, and, secondly, a good exhaust fan system is important if for no other reason, for removing vaporized moisture from the home's interior, specifically in the kitchen area.
Matt
That noise thing is what I am going to tackle..I too am doing an Island with hood. I want to mount the fan outside on the wall about 10' away..thinkin about running the duct tween the cieling joists and isolate from vibration..how loud could these suckers be? Thanks
I want to mount the fan outside on the wall about 10' away
That's more or less what I did. Oversized hood is 44" above the cooktop. Works great. Recycled fan, so I don't know the cfm, isolated from the steel duct. Our noise level is not objectional.PAHS Designer/Builder- Bury it!
Dig it...that is what I hoped to hear. Did you make any provisions for cleaning or slope for I guess anything that might OOZE???..for draft uphill to the fan? I am going to fab the hood as well and cleanable filter..wonderin bout the pipe and a damper for when it is not suckin toupee's offa heads <G>..
Mine's a commercial hood, 3'x4'. Only things I fabricated were the filter housing and I reduced the outlet to 6" d. We haven't collected any grease downstream of the filter. But we aren't doing a lot of short order cooking. Why would you want a damper? I wired a switch into the island. Our ductwork is exposed, so easy access.
Uncle Dunc's thought about makeup air is something to consider. I don't look at it as a furnace question, but more a house air question. We have a ventilation system that slightly pressurizes the house such that leaks go out, like every house should experience. That way we have no ill effects from turning on the fan, or burning the wood stove. If you're planning on extensive exhaust run time, you would do well to look at your entire air system. Something you probably ought to do anyway.PAHS Designer/Builder- Bury it!
Air system..sorry but I have to chuckle. This place is 150+ yrs. old and virtually impossible to create positive pressure..I have no central heat (yet) BTW we are not living in it , it is under anesthesia at the moment while I gingerly remove various and sundry uneeded things, and add the needed parts...the logs are in need of serious chinking and likely some west.sys. or a total rootcanal and crown...I will be getting part of it habitable for occupation by Mar. The Kitchen is newer addition as is 2 baths and 2 BRs...thats why the focus for me will be to get the Kit almost complete to keep down the mess while the log 1/2 of the house gets re/done.
Building a copper hood..filters and light. I have seen and installed hoods (under micro, and over stove top) that had flap dampers when the fan is off the damper is counterweighted to close. I guess to keep out backdrafts?Thanks for the info..anyway, I am off to do some more surguery.
This place is 150+ yrs. old and virtually impossible to create positive pressure..
Yep, I was assuming a modern tight house. But if you leave yours leaky enough, maybe you don't need any exhaust system? PAHS Designer/Builder- Bury it!
600 cfm is not much in the grand scheme of things...
I have a peninsula that has a gas cook top and a small 30K btu restaurant gas grill. the hood is 30 x 60 and 36 above the counter top. have a 1200 cfm roof mounted fan with 10" x 4' straight flue. the fan motor has a rheostat variable speed control.
When it is full on it will allow cooking chicken on the grill, albeit very noisy. at other levels there is no noise problem. If you don't have a window cracked and a fire in the fireplace and searing steaks at full output the fireplace smoke will go over to the hood and up...The only time it needs to be full on is with the grill on and something that smokes a lot.
My suggestion is to get a big fan and use a variable speed control. You don't need 1200 cfm all the time...
Bud