In order to have a successful modern kitchen, safety must be prioritized. One way to prioritize safety is to introduce makeup air into your kitchen. Makeup air can improve air quality and decrease the likelihood of low-pressure systems forming in your home.
Before introducing makeup air into your kitchen, you must first determine whether you actually need it. Beyond this, there are a variety of factors that influence whether makeup air is important in your kitchen, including stove size, the weathertightness of your home, and more.
- Range hoods are more common
- Houses are more weathertight
- Gas ranges are making a comeback
- Kitchen ranges are getting bigger
- People are more aware of the importance of health and safety
Not All Domestic Kitchens Require Makeup Air
According to Section M1503.6 of the International Residential Code (IRC), a kitchen must have a supply of makeup air if there is a gas, solid, or liquid fuel being burned in an appliance in the home.
Additionally, the stove must use an exhaust system rather than a direct-vent or mechanical draft venting system.
Finally, the exhaust system must be vented at a rate of 400 cubic feet per minute (CFM) or more in order to require makeup air.
If any of these circumstances are not applicable, your domestic kitchen may not require makeup air.
For example, if you have an electric stove, combustion gases are not produced since gas, solid, or liquid fuel is not being burned.
Although range hoods can still be used in a kitchen that utilizes an electric stove, they are not required and, therefore, makeup air is not required.
Additionally, if the stove uses a direct-vent or mechanical draft venting system rather than a range hood exhaust system, makeup air is not needed.
Direct-vent appliances have their combustion centers separated from the room and linked directly to the outside.
Mechanical draft venting systems mechanically expel combustion products and don’t rely on passive pressure systems.
Even if you do have a gas stove and a range hood exhaust system, you will not need makeup air if your exhaust system is rated at below 400 CFM.
Why Makeup Air Is Important for Domestic Kitchens
1. Range Hoods Are Becoming Standard Practice
Despite the current popularity of range hoods in many homes, many states in the US don’t even require them, besides California, which requires mechanical ventilation in the kitchen.
Range hoods began to get popular in the US in the 1950s and 60s. They were both incredibly handy to have in the kitchen as well as ornate additions to the home.
These kitchen additions continue to be fashionable and useful today, even though range hoods are not necessary by code or law.
Moisture, grease, and smells from using the stovetop can all be removed with a range hood. This limits damage to the home through the reduction of moisture and grease.
Range hoods also protect the residents by removing harmful chemicals since combustion gases can cause nausea, headaches, and, in extreme cases, permanent damage to the body and death.
Despite the many advantages of having a range hood in the home, the inclusion of one means that makeup air may be required.
Makeup air allows for the quantities of air that are removed by the range hood to be replaced so that a low-pressure system isn’t created.
If makeup air isn’t introduced, this low-pressure system can draw in air from the outside, causing drafts in the home, making the HVAC system work harder, and causing structural instability where the air enters and widens gaps in the home.
2. Houses Are Getting More Weathertight
To prevent outside infiltration of the home, houses are getting more and more weathertight.
A weathertight home prevents leaks of both air and water, making the temperature control of your home easier and less costly and decreasing the risk of water damage.
However, with a range hood, a weathertight home can come with disadvantages.
When range hoods remove air, air must be replaced to prevent a vacuum in the form of a low-pressure system.
This air often enters the home through gaps and cracks in windows, doors, floorboards, baseboards, and more.
If your home is well-sealed, though, air won’t be easily replaced through a low-pressure system unless doors or windows are opened.
This may seem good at first since air entering through gaps and cracks can cause drafts, structural instability, and higher HVAC costs, but the air that enters due to the low-pressure system is needed to prevent other undesirable situations.
With makeup air, the air in your home can be replaced in a way that doesn’t involve drafts in your home.
The makeup air will also allow for fresh air in the home to prevent stagnancy. Without makeup air, there will be little ventilation in your home. It is likely that the air in your home will grow stagnant.
Stagnancy is harmful to health since air pollutants gather rather than being replaced by fresh air.
Stagnant air can contain allergens, combustion pollutants, smoke, and more, which can lead to adverse health effects such as headaches and nausea and the worsening of asthma and allergy symptoms.
3. Gas Ranges Are Making a Comeback
Ranges, also known as stoves, are kitchen appliances that contain both a stovetop and an oven.
With the advent of electricity, electrical appliances became the standard in most homes. However, over time, gas appliances have made a comeback for various reasons.
Gas ranges are known for their quick preheating times and overall better heat-control than electric stoves.
Despite their advantages, gas ranges have the glaring disadvantage of emitting the byproducts of combustion, which include carbon monoxide, nitrogen dioxide, and more.
Combustion gases can cause fatigue, headaches, nausea, and, in severe cases, with prolonged exposure, cancer, permanent damage to the brain and lungs, and even death.
This is one of the reasons why range hoods are in high demand, they remove large amounts of these combustion gases from the home.
Makeup air is also important in this situation, ensuring that there is no backdrafting of these harmful gases into the house and ensuring that the supplied combustion air is free to do its job instead of acting like combustion air.
The worst-case scenario would be a home with a gas range, without a range hood, and without makeup air.
Other forms of ventilation will remove some of these gases but without the removal and replacement of the air, it is more likely that these gases will stay around.
This can lead to adverse health effects and long-term problems if the gases are prevalent enough.
4. Kitchen Ranges Are Getting Bigger
The phrase “bigger is better” can apply to many things, and in this case, it applies to kitchen ranges.
Bigger ranges mean more space for larger cooking or baking projects. They can also mean saved time and money if you can cook multiple things at the same time rather than having the oven or stovetop running longer.
However, bigger ranges mean bigger range hoods. Bigger range hoods mean a higher CFM.
High CFMs mean that the air must be replaced faster to match the air that is exiting the hood. This must be done to comply with the IRC.
If makeup air is not introduced in this situation, the low-pressure system will be more powerful and its negative effects more pronounced.
5. Health and Safety Is Given More Importance
As society evolves in knowledge, we can often look back on past decisions and question why we made them in the first place. Asbestos is a prime example.
However, this situation applies to health and safety concerning the kitchen and exhaust systems in as well.
In years past, it may have not occurred to us that replacement air was vital for a variety of reasons, but now that we know the dangers of combustion gases and stale, stagnant air, we can move on with safer policies.
Makeup air can replace air that is full of allergens, pollutants, carcinogens, and combustion gases, improving the air quality of the home. It can prevent gurgling and smelly drains, high utility bills, premature HVAC failure, and more.