A balanced diet requires balanced ventilation
Balanced ventilation for a residential kitchen
Today's homes are built to be more energy-efficient. "Tighter" construction resists the infiltration of outdoor air through the home's exterior, which limits the amount of makeup air the home will permit. Of course, you can only exhaust out from the home as much air as is able to come back in. Without makeup air, even a powerful exhaust fan can remove only as much air from the home as is permitted via infiltration.
When an exhaust fan operates without sufficient makeup air, some undesirable results can occur:
The exhaust system will not work to its intended capacity
Kitchen hood exhaust systems are sized to remove cooking-generated heat, odors and contaminants based on the cooking equipment's dimensions and heat rating. Inadequate makeup air can prevent a kitchen hood exhaust system from adequately removing contaminants.
Backdrafting of chimneys and appliance vents
Insufficient makeup air will result in depressurization in the home. Depressurization works to halt the flow of hearth and appliance combustion products from exiting the home. This "backdrafting"can result in a dangerous accumulation of harmful gases in the home. Studies have shown that as little as 5 Pa (0.02" w.g.) depressurization can cause backdrafting.