Make-up air is additional air that “makes up” for or replaces air that is being removed in your home, room, kitchen, or other space by an exhaust fan or range hood.

You may require make up air if:

1. Your range hood pulls 1200+ CFM
2. You live in a small kitchen
3. Your kitchen is poorly ventilated
4. Your building codes require the use of a makeup air kit
5. You run your range hood for several hours at a time

We’ll go over each of these scenarios in more detail below. Also, we’ll discuss some of the most common questions we hear about make up air and range hoods to help you ensure that your home is properly ventilated.

Do I need make up air?

There is not a set cubic feet per minute (CFM) rating for your range hood that indicates you need a make-up air kit. But there are several different reasons you may require make up air in your home.

Be sure to check out the video below for more information on make up air.

Your range hood pulls 1200+ CFM

The more powerful your range hood, the more likely that you will require makeup air. Hoods under 900 CFM don’t remove air from your kitchen as quickly as higher CFM hoods so they don’t often require makeup air.

Even with a powerful hood, you may not require makeup air if it is installed in a large kitchen or well-ventilated space.

However, if you live in a small space or the ventilation is not adequate, make up air is likely a good option for you.

Why? Well, when you turn your range hood on and it pulls air from your home, that air is gone and it needs to be replaced. If this air is not replaced, you may experience worsened indoor air quality or even shortness of breath.

You live in a small kitchen.

If you’re in a small space, there’s not a lot of cubic feet of air, so you may run into problems if you run your range hood for too long or if your range hood is powerful.

Simply put, the amount of air in your kitchen depends on its size. The smaller the kitchen, the less air it has; the larger the kitchen, the more air it has. 

Because of this, you may run into problems if you run your range hood for too long or if your range hood is a high CFM. 

In a really large kitchen, even a 2000 CFM hood may not require make-up air. But, imagine the following:

Say you want to buy a 1600 CFM vent hood for your 250 square foot kitchen. In this case, since this is a pretty large kitchen, you probably won’t require make-up air, unless you’ve got other exhaust fans in your kitchen as well. 

Compare this to someone who wants a 1600 CFM vent hood for their 70 square foot kitchen. This will pose some problems with ventilation and the lost air must be replaced somehow. In this case, you’ll definitely need a make-up air unit – and even that may not be enough. You may need to purchase a lower CFM hood or run your hood exclusively on the lower speeds.

So, it’s important to be mindful of the CFM of your hood if you have a small kitchen in your home. Our 600 CFM range hoods are a great option for your small kitchen.

For your reference, small kitchens on average are 70 square feet or less. The average kitchen is between 100 to 200 square feet, and large kitchens measure above 200 square feet,  according to Tops Kitchen Cabinet.

Your kitchen is poorly ventilated.

If you don’t have a lot of moving air in your kitchen naturally, a make up air unit will drastically improve the ventilation. It will bring fresh air in as your stove hood moves the greasy cooking exhaust out.

Here’s how it works.

The vent hood catches cooking exhaust and sends it through your ductwork outside your home. Then the make up air kit will bring outside air into your home to replace the air that was removed. It’s an incredibly effective way to improve your indoor air quality.

Your building codes require the use of make up air systems.

Some building codes will require you to purchase a make up air unit. Usually, the code will make this requirement based on the CFM of your range hood. For example, they may require make up air units for hoods over 600 CFM. You might see a code like this in smaller buildings like apartments or condos.

You run your range hood for several hours at a time.

As we’ve said above, the air that exits your home has to be replaced. But this takes time; it doesn’t happen instantaneously. When you run your hood on for extended periods of time, the air is constantly leaving your home. So, you are not allowing enough time for it to be replaced.

if you run your vent hood for several hours a day, even at a low CFM you may require make-up air.

At a high CFM, running your range hood for long periods of time is not recommended. No need to worry though; keeping your range hood on for hours is often not needed. A high-CFM hood will filter contaminants out of your home in just a few minutes.

What is make up air for a range hood?

A range hood exhausts air outside your home. Then, make up air for your range hood helps replace the air that is lost.

A range hood removes unwanted kitchen air from your home and then vents this exhausted air to the outside.

You may be wondering: how does make up air work for a range hood? Well, range hoods work with what’s called a make up air kit.

What is a make up air kit?

A make up air kit – also called a make up air unit or makeup air system – includes a range hood damper and air pressure sensor that controls the flow of outside air into your home. It attaches to your ducting, and a pressure switch signals to the damper to release and bring fresh air into your home.

A make-up air kit will greatly improve the ventilation in your home and help improve your indoor air quality. It can also cool down a room, if you’re doing a lot of high-heat cooking.

To purchase a make up air kit from Amazon, click here.

Hopefully this article on make-up air is helpful for you. Let us know if you have any questions by calling our support line at (877) 901 – 5530.

Related Articles

• Range Hood Duct Sizing Guide
• 5 Best Proline Wall Mount Range Hoods
• Do I need a damper for my range hood?

As an Amazon Associate, we earn from qualifying purchases.