Worried About Air Quality Risks in Your Kitchen? Here’s How Proper Ventilation Can Keep You Healthy and Stress-Free

Photo by Becca Tapert on Unsplash

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If you’re worried about indoor air quality and its effects on your health, you’re not alone. The facts are stacking up, and it turns out that what we’re breathing in our homes has a major impact on our short- and long-term health.

Indoor air can be up to 5x more polluted than outdoor air, and your kitchen is potentially one of the most polluted places in your home. From harmful particulates to molds to VOCs (harmful chemicals) from sources such as cooking fumes and cleaning products, the pollution can be impactful.
 
One of the activities that causes the most change in air quality is cooking. Depending on what you cook, how you cook it, and on what type of stove or range you’re cooking, you’re releasing nitrogen dioxide, carbon monoxide, CO2, particulate matter, and other potentially harmful compounds into your air. 
 
With over ninety years in the ventilation industry, we’ve been working to improve the health of indoor air for homeowners across North America. This gives us a unique perspective on the importance of indoor air quality (IAQ) and the best equipment and practices for improving your health through cleaner air. In this article, we’ll address: 

• Recent research on cooking with gas.
• What specific pollutants are being released into your home when you cook.
• Health problems associated with poor indoor air quality.
• The problem with many hood ranges.
• What to look for when choosing a hood range.

Recent Research on Cooking with Gas

Gas stoves have hit the headlines recently with research out of Harvard and Standford coming to light. While the research isn’t wrong, it’s important not to vilify gas powered stoves and ovens. Yes, gas stoves emit potentially worse pollutants at higher levels than electric, but the fact is—all cooking contributes to poor indoor air quality.
 
That’s right. It doesn’t matter what type of range or stove you have; it’s putting things in your air that you don’t want to breathe.
 
However, the statistics coming to light around the impact of gas cooking do require attention. Most of us know the dangers of gas leaks and carbon monoxide poisoning, but thanks to recent research, we now know that gas stoves produces a large handful of other harmful pollutnants. Here are some of the latest findings from a recent Harvard study:
 

• 12.7% of childhood asthma cases are linked to gas stove usage.
• 76% of methane emissions from gas stoves happen when the stove is off.
• Methane gas leaks can be undetectable by smell until they reach dangerous levels.
• One Massachusetts study found 21 chemical compounds that are federally designated as hazardous.
• Many chemical emissions from gas stoves rise well above EPA standards for safe levels.

 
The biggest battle being fought right now is the battle of information. Because the chemicals in the air are invisible and often odorless, it can be difficult to believe they’re having such an impact. Furthermore, if you’ve lived with gas for any length of time, you may have health impacts that you take for granted such as seasonal allergies or frequent headaches.
 
Fortunately, researchers have been able not only to identify which harmful chemicals are entering your home, but also their quantities.
 

What Specific Pollutants Are Being Released into Your Home?

Cooking releases many harmful compounds into the air. Some of these pollutants may depend on whether you’re cooking with gas or electric and can include:
 
Methane: A Stanford study found that gas stoves emit up to 1.3% of the gas they use as unburned methane. Methane is a substance more than 25x more potent than carbon dioxide and is finally beginning to be noticed by climate scientists. Methane concentration in the atmosphere has more than doubled over the past two centuries. 
 
Nitrogen Oxides: These gases are highly reactive and have been found to be directly correlated with the use of gas stoves. There are currently no guidelines in the U.S. for exposure to nitrogen oxides. However, studies show that people who don’t use their hood range or have poor ventilation exceed Canada’s guidelines for safe nitrogen oxide levels within one hour.
 
PM_2.5: Fine particulates are released when cooking on either gas or electric. Their quantities are dependent on what and how you’re cooking.
 
Depending on the region and utilities, other harmful chemical compounds found when cooking can include benzene, toluene, ethylbenzene, and total xylenes.


Health Problems Associated with Poor Indoor Air Quality

There are very real, very imminent health threats associated with these chemicals when proper ventilation is lacking. According to the EPA, some of these risks include:

• Irritation of eyes, nose, and throat
• Headaches
• Dizziness
• Fatigue
• Respiratory disease
• Heart disease
• Cancer

The Problem with Many Range Hoods

Many people believe they have proper ventilation in their kitchen, but, unfortunately, they don’t.  
One common problem with kitchen ventilation is the question of where to put the microwave. Microwaves mounted over stoves may save space, but the cost to your indoor air quality is high. Most, over-the-range microwaves only cover the back burners, which are often not used. Most are underpowered and have poor capture efficiency (the ability to capture what’s coming off the range). A properly sized range hood, on the other hand should be built to capture much of what is coming off all of the range’s burners.


How to Use a Range Hood

Another problem is that people generally do not know how to properly use their range hood.
In a recent study by Virginia Tech, only 8% of respondents said they regularly used their kitchen ventilation when cooking. That’s an awfully low number when you and your home’s health are potentially at risk. A good rule of thumb is to turn the range hood on 5 minutes before cooking and for 30 minutes after you have finished. Turning the hood on before cooking gets the air flowing out of your home so that when you begin cooking the pollutants already have a path. Leaving the hood on for 30 minutes after you are finished, helps to ensure that you have removed any lingering odors, smoke, and other pollutants.


What to Look for When Choosing A Hood Range

Ventilation can’t be an afterthought; not when it comes to your health. When you’re ready to put a priority on proper ventilation in your kitchen, here are some things to consider:
 
Is it big enough? Make sure the hood range you choose extends far enough out from the wall to capture emissions from all of your burners. With a proper fan, this could be as little as twenty inches from the wall, but is likely more. It should also be wide enough to cover the entire range. The most common width for a range/oven is 30 inches.
 
Is it powerful enough? A good rule of thumb is to move 10 cubic feet per minute (CFM) for every 1000 BTUs. So, a 10,000 BTU range should be paired with a 100 CFM range hood. For those really big ranges the hood may need to reach into the 600 CFM+ level.
 
Where is the air going? You want to make sure your range hood is venting pollutants out of the home. This is the ideal scenario. It ensures that all of the harmful contaminants in your home are removed, not just filtered. That said, you may be in a home, apartment, condo, or other living situation where you are unable to vent pollutants out. A recirculating range hood is a good solution here, but make sure it is sized properly and that you change the filter often (based on how often and what you cook).
 
Do you need make-up air? Assuming your range hood is taking air out of the home, you may need to consider having a make-up air damper installed to bring in outside air to replace what’s being taken out. The general rule of thumb, that is also often the building code, is that if your hood moves more than 401 CFM of air, you need to put in a make-up air system.
 
If you have any further questions or concerns about the air quality in your home, we’re happy to talk to you about your options and help you locate an IAQ licensed contractor.