How to Plan Your Make-Up Air System
Key Takeaways
- Physics, not malfunction – Your range hood needs makeup air to work effectively in modern airtight homes.
- Required by code – IRC Section M1503.6 mandates makeup air for hoods over 400 CFM.
- Two main solutions – Passive systems (simple but cold) vs. Active systems (controlled and comfortable).
- Safety first – Prevents dangerous backdrafting and carbon monoxide buildup from furnaces and water heaters.
Table of Contents
Have you spent thousands of dollars on a professional kitchen setup and bought a CFM range hood powerful enough to hover a small dog? But when you cook, your house still smells like smoke. Have you ever noticed your ears popping when you close the front door?
It's not your hood that's broken. It's physics, and today, we are going to show you exactly why your expensive kitchen ventilation system is choking.
Check out the video that explains how to plan your makeup air system:
Water Bottle Experiment
To understand your kitchen, you have to understand that air is a fluid; it moves just like water. So, think of this bottle in the picture above as your house, and the water as the smoke, grease, and heat you want to get out.
Let's say this is a modern, airtight home without a make-up air solution. As we uncork the bottle and pour it into a container, we see turbulence. The water, or in other words, your smoke, is trying to leave at a rapid pace, but physics won't let it. For every cubic foot of air that leaves, fresh air has to fight its way in to replace it. It's slow, loud, and very ineffective.
We have now poked a hole in the bottle to show you what it'd be if you had makeup air systems installed in your home. Now, as we uncork this bottle, the water comes out smooth, silent, and quite fast. We didn't change the size of the opening at the bottom; we just gave the replacement air a way inside your home.
Vacuum Effect & Negative Pressure
When your kitchen hood is fighting against itself like the first experiment, it creates negative pressure inside your home. And that vacuum is looking for outside air anywhere it can find it, through door frames, windows, and even your HVAC system.
That building pressure is powerful enough to reverse the flow of your chimney, and that is called backdrafting. This can pull dangerous carbon monoxide from furnaces and water heaters into your interior space. We actually have a full video that you can check out, all about backdraft and how to troubleshoot it even more.
Check it out here:
Required By Law
Is makeup air required by law? The short answer is: Yes, but only if your hood is over 400 CFM.
According to IRC Section M1503.6, which is the International Residential Code for makeup air requirements, it mandates that the makeup air system be automatic. You cannot just open a window. The code requirements assume you'll forget to open that window when it's 10 degrees outside, and frankly, the code is right. It is also a safety net to prevent dangerous combustion gases like carbon monoxide from furnaces, water heaters, and stoves from getting into the living space.
This is especially critical here in Utah or anywhere where the air temperature gets really low in the winter. If you dump -10°F air into your kitchen through a passive air inlet, which is usually an air duct that connects from the inside of your house to the outside with a make-up air damper waiting for that pressure to change, you're running the risk of freezing your pipes. In cold climates, you often need tempered air systems that heat the air before it enters your home.
Fixing the Problem
So how do we actually fix it? There are two main options for your air replacement needs:
Remember: You wouldn't buy a Ferrari engine and keep the stock tires. An active system with proper duct size and airflow rates allows your luxury hood to actually do its job. Whether you're outfitting a residential kitchen exhaust or a commercial kitchen, the right mechanical ventilation makes all the difference.
Testing Your System
Here's a way to test right now in your house to see if you're having problems with static pressure: Turn your hood to the max, then unlock the front door. If it feels like it's glued shut, or if it feels harder to open, or if it opens violently, your house is definitely experiencing negative pressure issues.
Don't let your kitchen choke. Give it the clean air it needs so your kitchen ventilation system can work as best as it possibly can.
Conclusion
Overall, if you have a high-CFM range hood (over 400 CFM), you will most likely need makeup air systems to meet code requirements and ensure proper ventilation. Whether it's a whole-house solution or a targeted air intake for your kitchen, the right make-up air solution prevents backdrafting, maintains air quality, and allows your exhaust system to operate at peak performance.
No need to stress because we are here to help every step of the way. Feel free to reach out with any questions that you may have. You can contact us by phone or email address: support@prolinerangehoods.com
NOTE: Proline Range Hoods aren't capable of being hardwired in with makeup air systems.
If you are looking for an upgrade for your kitchen, though, we have an amazing catalogue of stainless steel range hoods with free shipping, where I'm sure you'll be able to find the perfect range hood for your home.
Ready to upgrade your kitchen ventilation? Explore our complete collection of professional-grade range hoods with free shipping.
Take the Range Hood Quiz
