Do I Need Make Up Air In My House?

by | Last updated on January 24, 2024

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Makeup air is

needed in homes to replace air that is removed by mechanical devices

, such as clothes dryers, kitchen exhaust fans, and bathroom exhaust fans. Makeup air is not the same thing as combustion air. Combustion air is needed to support combustion at appliances such as a furnace or water heater.

Is makeup air the same as outside air?


Makeup air is outside air that replaces air exhausted from inside the building

. In most houses, there are several appliances that push or pull air out of the house, including clothes dryers, bathroom fans, fireplaces and kitchen range hoods.

What is make up air in a house?

WHAT IS MAKE-UP AIR? Make-up air is designed to

“make up” the air in your interior space that has been removed due to process exhaust fans

. This type of HVAC solution pulls in fresh, tempered air from outside your building to replace existing air that cannot be recirculated.

How does a make up air system work?

Simply stated, a make up air unit

pulls air in to your space from outdoors and conditions it to the indoor temperature

, to replace air that’s pulled out by your kitchen exhaust equipment. Without it, you get back drafting, poor temperature control, negative air pressure and air quality problems.

How much make up air do I need?

800 CFM would require a minimum vent size of 7” but most professionals would use an

8” or 10” vent

to increase the efficiency of the hood vent. So, if you use an 8” duct above your range, then you need to bring in a minimum of 8” of “make-up air”.

How do I make up air?

  1. Connect an outside air duct to the plenum on the furnace (if the house has a forced-air heating and cooling system).
  2. Install a makeup air kit from Fantech or Electro Industries.

Does every room need a vent?

Your Home Might Not Have Enough Return Vents

Having several return vents (

ideally one in every room

, but even two or three is better than just one) creates consistent air pressure. If you have one return vent, your home is fine. Keep the doors to each room open so air can properly circulate.

What is a direct fired makeup air unit?

A direct fired make-up air unit is

used when fresh air has to be introduced from outdoors for ventilation purposes

. Its primary purpose is to ventilate the space adequately in order to preserve and maintain acceptable ambient air quality. These appliances supply heated or cooled air, depending on the building’s needs.

What is HVAC used for?

Defined: HVAC stands for

Heating, Ventilation, and Air Conditioning

. HVAC refers to the different systems used for moving air between indoor and outdoor areas, along with heating and cooling both residential and commercial buildings.

What is combustion air?

What is combustion air? Combustion air is

a source of oxygen needed to burn fuel such as natural gas or liquid propane

(LP). You can’t produce a flame in a furnace without proper combustion air. The image above shows the combustion air as a vent in the garage to pull air from the attic.

How do I know if my makeup needs air?

Calculate the required volume.

Divide room volume

(Step 1) by total/1000 (Step 2). If less than 50, additional air is needed. If greater than or equal to 50, no additional air is needed.

How much CFM do I need for air makeup?

Beginning in 2009 and in every version since, the International Residential Code (IRC) has required that makeup air be provided for kitchen hood exhaust systems with capacity of

400 cfm or greater

.

What happens if you don’t have make up air?

What happens if you don’t have enough make up air supply? Without enough make up air,

the building pressure becomes negative

. … When your exhaust hood is removing more air than you are replacing, it can cause everything from changes in the performance of your exhaust hood to excessive grease and smoke from your hood.

Is a kitchen exhaust fan required by code?

Although

range hoods are not mandatory

according to the IRC, California code requires mechanical ventilation in the kitchen that exhausts 100 CFM (intermittent ventilation) or allows 5 air changes per hour (continuous ventilation). Range hoods are a good way to meet this requisite mechanical ventilation.

What is Mua in HVAC?

The function of the MUA unit is in the an initialism; make up air to the building that gets exhausted from kitchen, bathroom and or dryer exhaust systems. … The building ventilation and the MUA system need to work together to ensure the building pressure is maintained.

Emily Lee
Author
Emily Lee
Emily Lee is a freelance writer and artist based in New York City. She’s an accomplished writer with a deep passion for the arts, and brings a unique perspective to the world of entertainment. Emily has written about art, entertainment, and pop culture.