Air Intake To The Attic

Attic square footage 2 square inches of exhaust and square inches of intake net free area nfa needed.

Air intake to the attic.

Hot air exhaust vents located at the peak of the roof allow hot air to escape. When using any type of powered ventilation product for an attic application all passive attic vents will become sources for air intake. Fresh air intakes are a key component the hvac system utilizes to maintain a safe and comfortable indoor environment in your home. Ventilation manufacturers assign an nfa value to the non motorized vents they make.

Snow melts and the water refreezes on the cold eaves creating ice dams. Nfa is the unobstructed area through which air can pass through a vent usually measured in square inches. We are going to discuss what a fresh air intake is and how a properly installed fresh air intake can increase your unit s efficiency performance and prolong the life of your furnace. Warm air that escapes rooms below gets trapped in the attic.

This return air intake grille typically includes some type of filter to keep dust and debris out while allowing air to pass through. See figure 2. According to the national roofing contractors association nrca a power vent with an airflow rate of 1 0 cubic foot per minute per square foot of attic space measured at the attic floor is generally considered to be equivalent to a 1 150 ventilation ratio. Grab a flashlight and inspect your attic during the winter.

Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic. Having your hvac system in your attic isn t dire though you ll need to do some work to keep your air conditioner or furnace system running as efficiently as possible. Warm air that escapes living space also carries moisture that will condense on rafters or roof sheathing. The first and possibly most important thing is to make a commitment to yourself to change your hvac filters regularly.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. The air passes through the filter of the unit and quickly passes over the supercooled coils inside. We will also cover how fresh air intakes play a vital role in determining your. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space.

Unlike passive ventilation where air flow must travel from the lowest point in the attic to the highest powered ventilation uses air intake from all areas of the attic both high and low.