Why is Make-Up Air Important?
Modern homes are equipped with several appliances that, when in use, exhaust the indoor air to the outside, including clothes dryers, water heaters, gas stoves and HVAC systems. The problem is the exhausted air is not replaced, causing the home to become negatively pressurized.
One of the many drawbacks of having a pressure imbalance in the living space is depressurization, caused by exhaust fans contributing to conventional fuel-burning appliances filling the area with harmful gases, known as backdrafting.
Proper ventilation is critical, especially in the kitchen, to avert the buildup of carbon monoxide and reduce lingering odors. Kitchen ventilation hoods play a vital role in effectively removing the harmful byproducts and stale air to a certain degree — however, fresh air must be introduced into the space through a Make-Up Air Vent to replace the exhausted air.
Residential Make-Up Air Requirements (IRC M1503.4) For Range Hoods
In residential environments, the International Residential Code (IRC) provides guidelines to ensure that range hoods are installed correctly and function efficiently. Many gas range and cooktop manufacturers recommend an output of well over 400 CFMs for a ventilation hood, especially when multiple burners are used at the same time. While not all residential buildings are mandated to have range hoods, when they are present, there are specific requirements that dictate the necessity to install a Make-Up Air Vent to restore exhausted air and provide balance:
- For hoods with a certain CFM (cubic feet per minute) output, typically over 400 CFM, there are specifications for a Make-Up Air Vent to compensate for the air exhausted to the outside, preventing negative pressure scenarios that could impact the home’s heating, ventilation, and air conditioning (HVAC) system.
A Make-Up Air Vent is necessary in the home's kitchen to maintain optimal air quality and provide adequate ventilation. Without a fresh air intake vent to provide outside replacement air, the kitchen's exhaust hood can struggle, leading to poor performance and efficiency, increased grease buildup and compromised air quality. A Make-Up Air Vent ensures a steady flow of fresh air, improving the performance of the kitchen’s exhaust hood and balancing the air in the space.
FreshVent allows for improved air quality by ensuring a steady flow of fresh air to replace the air that’s extracted to the outside through the exhaust hood. FreshVent improves the air quality by working in tandem with the exhaust hood to help remove contaminated air containing smoke and any volatile organic compounds (VOCs) that result from high-heat cooking, replacing it with fresh air. This improved air quality balances the environment and helps to lessen the accumulation of grease buildup in the kitchen.
Overall, make-up air — especially in the kitchen — ensures a steady flow of fresh air to balance the spatial pressure. Make-Up air reduces odors and contaminants and is essential to promote a healthier and more comfortable indoor environment for all occupants.