![Basic Refrigeration Heat & Air Conditioning [logo]](https://basicheatandac.com/wp-content/uploads/2026/02/basic-logo-transparent.png "basic-logo-transparent"){kind=logo}
Kitchen Exhaust & Makeup Air in Bloomfield, New Jersey
A powerful range hood solves one problem and quietly creates another. It pulls smoke, grease, and cooking fumes out of the kitchen, and in a tightly sealed house it also pulls the house into negative pressure, which can drag combustion gases backward down the flues of your furnace and water heater. Basic Refrigeration Heating & AC handles kitchen exhaust fan installation and makeup air systems together, as one ventilation job, for homes and commercial kitchens across Bloomfield and North Jersey. Our Master HVACR-licensed technicians size the exhaust to the cooking and the makeup air to the exhaust, so you get the hood you want without the safety problem it can cause.
Kitchen Exhaust Fan Installation Done Right
A kitchen exhaust fan is only doing its job if it discharges outdoors. Code requires range hoods to vent outside through smooth, rigid metal duct, with a backdraft damper, and never terminate in an attic or crawl space, where exhausted grease and moisture would just accumulate inside the structure. Recirculating hoods filter some grease and return the air to the kitchen; they remove no moisture and no combustion byproducts. Proper kitchen exhaust fan installation means sizing the duct to the fan, keeping the run short and smooth, and terminating it correctly at the exterior. A powerful hood strangled by an undersized or corrugated duct performs like a weak one.
What a Makeup Air System Does
Every cubic foot of air the hood pushes out of the house has to be replaced by a cubic foot coming in. In a leaky old house, that replacement air seeped in through the envelope. In a tight house, the hood has to fight for it, and the house goes under negative pressure. A makeup air system is the deliberate answer: a dedicated outdoor air duct with a damper that opens when the hood runs, supplying replacement air at roughly the rate the hood exhausts it. A makeup air unit can also filter and temper the incoming air so the kitchen doesn't get a blast of January with every use of the hood. The result is a hood that performs at its rated power without depressurizing the rest of the house. And a house that's tight enough to need makeup air is usually tight enough to benefit from balanced fresh air through an ERV or HRV as well.
The 400 CFM Rule
This isn't just good practice; it's code. The International Residential Code requires exhaust hood systems capable of more than 400 CFM to be provided with makeup air at approximately the same rate, equipped with a damper. That threshold exists because 400 CFM is where a hood starts moving enough air to overpower the natural draft of gas appliances in a typical home. If you're shopping for one of the high-powered hoods that serious cooking calls for, the makeup air for the range hood isn't an add-on to consider. It's part of the installation, and an inspector will look for it.
Backdrafting Is the Real Safety Issue
Here's what negative pressure actually does. Your furnace, boiler, or water heater vents its combustion gases up a flue using natural draft: hot gas rises. A strong enough exhaust fan reverses that, pulling air down the flue and into the house, and the combustion gases (including carbon monoxide) come with it. You won't see it happen. The signs are subtle: a furnace closet that smells like exhaust when the hood runs, a fireplace that puffs smoke into the room, a pilot light that struggles. If any of that happens in your house when the range hood is on, turn the hood down and treat it as the warning it is. Makeup air is the engineered fix, and it's the reason the code requirement exists. It's also one piece of how the whole house breathes; the pressure balance the hood disturbs is the same balance that basement and whole-home ventilation is designed around.
Commercial Kitchen Exhaust
Restaurants and commercial kitchens run this same physics at much higher volume. Commercial kitchen exhaust moves far more air than any residential hood, which makes makeup air a foundational part of the design rather than an accessory, and puts the whole system under commercial code and health inspection scrutiny. We install kitchen exhaust and makeup air systems for commercial kitchens across North Jersey, sized to code requirements, and we coordinate with inspectors and general contractors the way the shipped work on the rest of the building demands. If your kitchen's exhaust is underperforming, or your front-of-house doors whistle when the line is cooking, the exhaust and makeup air balance is the first thing to check.
If the hood can move more than 400 CFM, the residential code requires makeup air at roughly the same rate as the exhaust. Below that threshold it depends on the house: a tight home with natural-draft gas appliances can have backdrafting problems at lower flows than a leaky home with sealed-combustion equipment. The honest answer comes from looking at the hood, the house, and what else in the home burns fuel.
Related Custom Ductwork Services
ERV and HRV Installation
Balanced fresh air with energy recovery for tightly sealed homes. Learn more about ERV and HRV installation.
Basement & Whole-Home Ventilation
Fixing musty basements and stale houses at the root cause with air that actually circulates. Learn more about basement and whole-home ventilation.
Call Us
Business Hours
Request Appointment
Expect a call within an hour during business hours or before 10:00 AM the next business day.