Why it’s important to get a proper kitchen exhaust fan and USE IT

Recently (in the last few years) gas stoves have come under fire as a source of air pollution in homes.  While we used to think that the “blue flames” were clean-burning, it turns out that natural gas stoves (the kind of gas used in cities that is piped and metered to homes) can emit a range of pollutants from carbon monoxide, formaldehyde and other harmful pollutants into the air, which can be toxic to people and pets. (Indoor Air Pollution from Cooking)  Thirty-five percent of American homes cook with it, not to mention countless restaurants and commercial kitchens.  The problem is not using gas stoves in the home, however, it is using them with inadequate ventilation.  

Many older homes don’t have a kitchen exhaust vent, or if they do, it is not close enough to the stove or powerful enough to evacuate all the toxic fumes.  Nitrogen dioxide (NO2) is another common pollutant emitted by gas stoves, which the Environmental Protection Agency says is a toxic gas that even in low concentrations can trigger breathing problems for people with asthma or chronic obstructive pulmonary disease.  According to research, including this 1992 study, children who live in a home with a gas stove have about a 20% increased risk of developing respiratory illness.  NO2 concentrations can quickly spike when using as little as the oven and 1 burner without an exhaust fan, to more than double the EPA 1-hour standard of 100 parts per billion (ppb).  (We need to talk about your gas stove, your health and climate change)

Plus, we’re not even counting the burnt food bits that emit VOCs and fine particulates.  Our article about the air pollution cost of cooking–a favorite pastime of many–tells about a test kitchen where the Thanksgiving food items generated particulates levels exceeding that of Delhi, one of the cities with the world’s worst air quality!  You may be thinking about the time(s) a smoke detector may have been set off in your own home.  In my home, cooking during Thanksgiving set off my air quality monitor several times, from cooking bacon in the morning to toasting bread for the stuffing.  And I was using a kitchen exhaust vent, and, the monitor was a good 20 feet away, meaning that levels were even higher at the stove.  Yikes.

It’s just time to cook healthier, and I’m not talking about the type of cooking oil or how much butter you use.  It’s all about the exhaust vent.

If you live in a home with an existing exhaust vent, like a small combination microwave-vent, the first thing to do is check its rated throughput.  Most fans will have a brand and model number somewhere accessible, and the internet is a great resource for looking up this information.  

In our article here, I walk you through calculating how many cubic feet per minute (CFM) of air the hood must move in order to vent properly (it depends on the size of the stove and the size of your kitchen).  Many small vents and microwave combo units are just not powerful enough for the width of stove they are supposed to cover!  That’s exactly why the air quality alarm went off in my home even while the exhaust fan was at the highest setting.

If your vent falls short in the CFM department, or you don’t have a vent, it’s time to upgrade it or supplement. Here are some things to consider if you upgrade:

• Noise: get the quietest fan you can afford.  Really.  A noisy fan is a big deterrent to actually using it, and the kitchen is a gathering place, so you’ll want to have a fan that makes it easy to enjoy cooking and holding a conversation.  Most of them will operate between 6 and 10 sones, or around 53 to 61 decibels. A normal conversation comes in at around 6 sones, so finding a range hood that operates in that range or below will make it much easier for you to enjoy carrying on conversations in the kitchen. (How loud should a range hood be?)  Another quiet (more installation-oriented) option is to get a model that has a remote fan, which can be installed away from the kitchen in the exhaust line.

• Direct-Current (DC) Motors: More and more appliances are using DC motors and the advantages are several: they are slim and compact, they are more energy-efficient than their AC counterparts and speed control is easier.  In addition, it may have a longer life and quieter operation.

• Other features such as LED lighting, optional filtration and pressure--balanced models are available.

• Make sure to vent outdoors whenever possible.  If you cannot vent outdoors due to where the stove is located or if you’re renting (see below), look for fans with carbon filters that are easy to replace.  Activated carbon removes NO2, as well as VOCs, as long as the fan is powerful enough (see CFM discussion above) and you change the filters on a regular basis.

Here are some good values:

• FIREGAS Under Cabinet Range Hood 30 inch with Brushless DC Motor, $100: If you are gifted with DIY capabilities or know someone who is, this fan looks good and is well-endowed with all the perks mentioned above such as a DC motor and LED lights.  The capacity is 300 cfm and noise level is 45 dB, which is amazing for this price level. It can be vented indoors or outdoors. 

• CIARRA Under Cabinet Range Hood 30 inch Vent Hood for Kitchen with 3 Speed Exhaust Fan, $160: This fan is only 200 cfm, but it has good reviews and for small kitchens it may work just fine (again, see sizing requirements). 

If you don’t have room to exhaust outside above your stove, consider adding a wall fan with outdoor shutter closure:

• AC Infinity Room to Room Fan 8”, Two-Way Airflow Through-the-Wall Fan with Temperature Controller, $99, is a brand that is known for good reliability and excellent motor controls.  The maximum speed is 305 cfm with 48 decibels, which is adequate for many stoves/kitchens.  It can be plugged in or hard-wired.

• SAILFLO Exhaust Shutter Fan 8 Inch 300 CFM, $48, is easy to install because it has a plug connection, and easy to operate with a pull chain. It does reverse to push air into the kitchen (you may on occasion want that feature when not cooking), but has only one speed in each direction. 

We also realize that many people rent or live in an apartment where it’s impossible to access the outdoors, or just don’t have any say about installing permanent equipment where they live.  We get that.  Thankfully, there are several portable inventions nowadays that can help get the purifying power you need.

• CIARRA Portable Range Hood, Desktop Range Hood with 2 Speed Exhaust Fan, $170, would work well for college dorms with a hotplate, micro apartments, or small campers.  It’s not for use with open flame cooking, only electric griddles or hot pots.  It moves about 100 cfm, which is sufficient for this type of cooking, and comes with carbon filter and an optional HEPA filter (although this may clog up quickly if you’re cooking greasy food!)

• AirHood ($157-$197) is another small portable kitchen exhaust fan, and comes in wired or wireless models. The downside is that this model is 70 dB, which may be loud for some people.  It does not specify CFM but can be used with open flame cooking with adequate distance between the flame and the unit.

• Air King 9155 Window Fan, 16 inch, White: $147, is a powerful fan that would work well if you have a window in or near your kitchen, preferably close to the stove!  Of course, it could get a bit greasy when drawing cooking fumes, but the fan can be taken apart and cleaned.  It also allows you to close the window behind it during stormy weather without removing the fan.

With so many options out there, there’s hardly any reasons NOT to get proper ventilation for your stove/oven.  The important thing is to USE IT…make your family members or roommates aware of the dangers of NO2 and particulates.  Even toasting bread releases a lot of particulates from the bread as well as all the crumbs left from previous toastings.  So, it’s best to turn your exhaust fan on while cooking anything in the oven, range, toaster or microwave, and leave it on for up to an additional 15 to 30 minutes after you're done to evacuate all those gasses and particulates (and smells).  The plus is that with carbon filters, you don’t have to put up with cooking smells lingering for the rest of the day (well, cleaning the cooking pans is required too).  Here’s to fresh air and easier breathing with the right kitchen exhaust fan!

Photo by Erik Mclean on Unsplash