Why does your range hood need a make up air system

What is make up air for range hoods

High cfm range hoods take out large volumes of air from the building space. If this air is not replaced at the same rate that it is expelled, the building will experience a negative pressure (the air pressure outside the building is greater than the air pressure inside the building).

A few common indicators of a negative air pressure problem are:

• Exterior doors are hard to open
• Drafts around doors and windows
• Range hood may not be drawing vapours properly
• Smoke from a wood burning fireplace is pulled into the room

PS11 Custom Range Hood Oyster White with Stainless Steel Trim

A make-up air system replaces the air that is expelled by a building's exhaust system, maintaining the proper balance between inside and outside air pressures while also providing many other benefits:

• Provides conditioned air back into the home - cooled in summer, warmed in winter, de-humidified
• Aids the proper functioning of range hood exhaust fans
• Improves air quality
• Stops backdrafting of fireplaces, natural gas fired furnace and hot water tank exhausts

In the colder northern hemisphere where the windows and doors are closed through the winter and where the homes have become increasingly air tight building inspectors are paying more attention to the need for make up air where high powered range hoods (some areas as little as 600cfm) are installed.