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nyrgirl35

Range Hood and Make up air

nyrgirl35
9 years ago

Hi. I will be getting a 36" gas range ( no griddle or grill ) all 6 burners. I added up all 6 burners and BTU's are 70,000. I checked to see what some 30" range BTU's and they are around 60,000. I have a 48" wood hood and my cabinet salesman suggested the Zephyr insert with 1000 CFM. I never had a ducted vent that will be added during renovations.
But now I'm freaking out after I read about make up air, I never heard of this before. I live in NY not sure of any codes here? But I'm not just worried about codes I'm also worried about this in general. I can't afford to put in system for make up air, what are my options? lower CFM? 400? 600?
It doesn't seem that my range has that much more BTU's then the average 30" range. I know I would never be using all 6 burners at the same time on max. My house was built in the 80's, the kitchen has vaulted ceilings, window is close to range ( not sure if any of this matters )! What's the lowest CFM I can use? I don't fry a lot other then your basic chicken chicken cutlets. I mean before I had a recirculating hood that never really worked so when I did fry I just cracked my window open. Should I just have stayed with recirculating? Never had a problem before with grease on cabinets or anything!
Sorry for the long post I'm just freaking because my reno starts on Monday and just read about this.
Thanks

Comments (6)

  • snoonyb
    9 years ago

    Generally, 1000CFM, shouldn't trigger that requirement.

    There are some areas, which by a function of code, require make-up air for kitchen venting appliances.

    However, in general, that determination is based upon the type of construction (how tight) as well as the openness of the interior spaces and the type and location of your comfort heating appliance.

    There are also both passive and active make-up air systems.

    Your venting appliance may also have speed (volume)
    control.

    Budgeting for contingency, the recommended venting of the cooking appliance, by that mfg., should be followed, not, well maybe I'll only use 1 burner today.

  • sjhockeyfan325
    9 years ago

    I've read on the appliance forum that the requirement for makeup air can be triggered by a hood as low as 400cfm. You have to check your local code.

  • missymoo12
    9 years ago

    My Pa 2009 codes required make up air for anything over 400 CFM.
    I am getting an American Range 36 inch and the manual doesn't give an exact requirement but I have installed a Zephyr monsoon DCBL it is 715 CFM
    I bought the Broan Make up air unit from amazon because I needed an 8"diameter vent duct for that Zephyr unit. The HVHC guys have it installed and everything works well. The MUA duct opens when an air finger trigger is activated in the range hood duct the make up air unit is connected via 12 volt wire. The duct pulls outside air into my air return vent prior to it going into the geothermal unit to be heated.
    Zephyr now makes their own MUA unit identical to the Broan.
    The inspector was of no help in choosing anything.
    The HVAC guys said just get a 300 CFM range hood. Knew about makeup air but had never installed.
    The Appliance saleperson gave me NO guidance.
    I got more info here on GW in the appliance forum.
    I basically had to wing it myself and tell the HVAC guys what to do.
    Wont know about inspections until Dec or so when we get our final.
    This is a major gray area in my locale. I am hoping I do not have to get an air heat exchanger to warm the air prior to it loading into the main air return. This is required with some HVAC units but may not be an issue with my geothermal. And that I am not under the newer 2012 codes.
    I love the Zephry. BTW - very quiet.

  • juliekcmo
    9 years ago

    I will say that if your hood vent is straight with no elbows then that is probably more cfm than you may need. If there are longer duct runs, or elbows, that does compromise the velocity of the air in the ducting.

    My previous house had a Thermador all gas range with 90,000 total BTUH output possible on the cooktop. I had straight up and very short duct run, and a good quality 600 cfm hood was very adequate.

  • kksmama
    9 years ago

    Good for you, getting a proper vent hood! You may enjoy the linked thread and NY Times article which inspired it.

    I chose to evade the expense and logistics of mua because my rangetop is the only gas appliance in my home (so no worry about backdrafting) and I rarely use high speed. When I do use high speed, I open a window.

    I calculated that if my hood really did exhaust 1200 cfm, it would take 20 to 30 minutes to replace all the air in my house. Hard to imagine that being necessary, but I do enjoy cranking it up on cool mornings and opening furthest window to air out the house.

    Here is a link that might be useful: spirited venting discussion

  • rwiegand
    9 years ago

    MA has no MUA requirement for a 1200 cfm residential hood. Our house is very tight so I need to open a window for the hood to work well on medium to high. The few minutes a week of having an open window seems a simple and sensible solution. (all of our gas appliances other than the range have sealed combustion chambers and their own MUA supplies, so backdrafting is not a concern.) There is no downside to having a big blower, as long as it has a speed control. Low for routine use and typhoon for charring the chili peppers in the wok.