The Field Controls Make-Up Air System solves the “sick house syndrome” caused by too tight home construction. This unique system provides fresh air automatically without using electricity or special controls. Also, it meters the air flow to keep the home in balance

With the Field Controls MAS (Make-Up Air System) there isn’t any negative pressure and there will not be any rushes of cold air during the winter or hot air during the summer seasons. The result is an even distribution of tempered air keep the home fresh, the furnace efficient, and the occupants comfortable.

The Field Controls Metering Air System consists of an Intake Air Hood which is installed through the wall to allow outside air in. The hood is connected via flexible 6″ duct or standard duct pipe (not included) to the metering air device. This device effectively meters the air inflow for proper air circulation, combustion, and balance.

How the MAS Works
The furnace ignites and the fan engages pulling air through the return air plenum. The Metering Air Device reacts to the negative pressure opening, to allow fresh air to enter via the Intake Air Hood and the duct pipe . As the pressure inside the home changes, the system reacts to keep the fresh air flow constant. The system is adjustable for homes from 1000 to 3000 square feet.

This table provides one-half air changes per hour, assuming an average ceiling height of 8 feet and a return air plenum pressure of .4 inches of water column: