Lifer - dhanna's right. Nothing we're putting is is 'commercial', marketing-speak just labels it 'commerical-style', or more commonly 'pro-style'. Much different than true pro equipment in that it's usually not quite as powerful (a burner on a Vulcan is 30k BTU, compared to 18k on the Wolf we're looking at), and they're extremely well insulated. A commercial appliance will burn you if you pretty much look at any of the surfaces wrong. You can touch the front apron or door on a Viking and it will be cool to the touch. So far as I know, Wolf, Jade, Viking et. al. are all approved for residential use. You can nestle them right between two cherry or MDF cabinets with no risk of scortching.
Tinknocker - very good idea. Unfortunately, the kitchen is 100% land-locked - no outside walls. Do you think this would work with another duct (or ducts?) up through the roof?
dhanna, just re-read your post and I have a question.
We probably will exchange the air in our house once an hour or so with the fan on, and we'll probably run the fan for about an hour at a time - typically - at half or full speed. We'll probably cook like this 3-5 nights a week.
So assuming negative pressure isn't pulling Radon and other evils out of my basement on a regular basis (which I though was a main concern in providing make-up?), what about the heat loss? Won't my house get cold (or hot) every night that we cook?
you are not makeing this easy lol
discribe the kitchen is the hood against a wall if so pull it out three inches or four and run a stainless steel duct against the wall to the attic and throught the roof. in the attic you can change the round pipe throught the roof
but the hood in against the duct so it will draw the air from it when needed also a damper to open when fan is on and close when off to stop drafts
if free standing run a duct on both sides of stove about three to four inches above the burners so not afect the flame down into the cellar and out the side wall with a louver
seems the key is to have the make up air as close to the hood as possible so it does not have an affect on the rest of the house.
tinknocker - if I made things easy, what fun would it be? ;-)
Seriously, I like your plan. It's certainly the most cost effective of anything described so far. The hood is against an interior wall; I was going to have them run the exhaust duct (8") against the wall and through the roof. Since this certainly can't be buried in a standard 4.5" wall, it would be attached the wall, and framed around to the ceiling (approx. 10 feet up; so it almost looks like a drywalled chimney to the ceiling). Since this 'chimney' will be as wide as the hood (42"), I guess I could run the make-up duct(s) right next to the exhaust duct. Maybe even a heat exchange in the middle? I'm still not certain of the geometry of the actual opening for these make-up ducts near the hood - moving the hood from the wall several inches?
I'll have to float this to our contractor along with the more active solutions, but if they keep recommending foolish fixes, I might have to have someone a bit more reputable take care of this after closing. Thanks for the idea. Anybody know anyone reputable in Cincinnati?
you may want to call a comercial kitchen exhaust contractor and find out what he can do for you also
this is what they do and they will know all the ins and outs
also at the same time they may have come across this problem at some time or another and can give you some real advise
I agree with no sweating at warm temperatures. I have seen several wet refrigeraters/freezers in cool damp basements. The space dew point and the temperature are near equal. When the refri/freezer surface drops below the dew point, the surface is wet. This is the least of the problems because it is easily cleaned. Other damp surface are more difficult. ERVs pass half of the moisture making the home wet at a slower rate. The home sill end up after a day of operation at the same moisture content as outside. After the wet weather passes, ERVs transfer moisture from the exhaust air to the fresh dry air entering the home. This is a double edge sword. They have no mechinical method of drying the home only slowing the wetting and drying. After you are all done, monitor your %RH with a good %RH meter. A couple days +70%RH in the coolest corner is a cause for concern. Dust mites start at +60%RH for a couple weeks. Mold at +70% for a couple days. Most people are not sensitive to mold and dust mites. Sorry about the scare tactics.
Originally posted by Carnak
It was a side by side style fridge/freezer and had all temperature settings turned down for coldest temperatures possible. Freezer was functioning as an ice making plant.
House was hovering around 86F and 85% RH, and my fridge/freezer did not sweat.
I keep my place about 80F, just 'shot' the fridge with my raytek, freezer side about 76.5, fridge side about 78.5. So would say worst case scenario is exterior temperature about 3.5 degrees colder than the room air.
Kitchen would tend to be the warmest room in house especially when cooking. So even assuming 75F in kitchen, freezer could be 71.5F. Unless this make up air blasted directly on the freezer, I do not see it sweating.
De-Humidifers have their use, but I think scare tatics are un-called for.
[Edited by Carnak on 04-07-2005 at 11:43 PM]
Not taken as scare tactics by me, teddy. That's good data - my wife has some bad allergies, so it's something to think about.
Rstagg, you have received some good advice and little or no bad advice as far as I can tell. I am a homeowner in S.Texas so have first-hand familiarity with some humidity issues -- and I am not forgetting your location in Ohio.
The main point I don't see stated elsewhere, is that with cool or cold outside temperatures, the air cannot hold enough moisture to increase your house humidity. For example I assumed an "ideal" for my house of 72 degrees and 48% humidity. If the air outside just happens to be 100% humidity and 51 degrees, when warmed up it will be that ideal. Your targets may be different of course, especially in winter.
Summertime of course is another matter. During summer the outside air usually holds enough moisture to increase humidity when cooled down to your indoor temperature.
You can get a little computer program for under $50 (some are free) to tell you all kinds of combinations. I have found it a big help in knowing when ventilation will help or hurt my goal of 48% humidity indoors. You can also get a humidity meter (with indoor/outdoor thermometer) at Wal-Mart for about $15.
I had a blower door test done on my house to measure its degree of air-tightness. Mine tells me I have .40 ACH (air changes per hour) in winter occurring naturally, and that 600 CFM imbalanced airflow would depressurize the house between 3 and 4 Pascals. In my hot-humid climate that would be very undesirable, I will leave it to others to judge the effect in a mixed climate such as yours. If your house is built like mine, and you do not install an intake to balance airflow, you will get that depressurization. I think that is an issue for you.
What seems the most elegant solution proposed so far, is that intake located very near the stove, so the intake air will be swept across the cooktop and disappear right out the exhaust. That would minimize any need to condition that air, and would be fairly cheap as well. To me that seems a direct and common sense solution to your problem.
Best of luck -- P.Student
deals with all this. I would advise against the ss duct through the roof since this will become a chimney once it fills with warm air(stack effect) and also constitutes a fire pass through and would surely be shot down by the AHJ if he knew what he was looking at(see, I have a sense of humor!).
I recommend the house have a blower door test along with Duct Blaster test. Seal the duct leaks to a reasonable level, seal the upper level leaks, then perform a Worst Case Depressurization Test on any atmoshpherically vented heaters. Now, using these tools, size and install a makeup air system to maintain the house as close to neutral as possible.
There are a growning number of systems to do this ranging from passive systems like the US Plusaire to powered systems with heaters such as available from Shelter Supply, which can use a slave switch to your largest exhaust fans such as the Suck-O-Matic over the range or the clothes dryer.
If you treat only one appliance and not the whole house, you will fail. As Collin pointed out, the penalty is not just cooking fumes in your face but possibly CO and backdrafting. While not adopted as a local ordinace, ASHRAE 62.2-2004 is a national standard that can now be used in court against you just like NFPA 211 for venting.
Keep the fire inside the fireplace.