Why Make-Up Air is Needed?

For an exhaust system to operate properly, fresh make-up air must be introduced at the same rate that contaminated air is exhausted. If a make-up air system is not a part of the exhaust system, then a negative air pressure condition is created. This increases the static pressure and causes a negative air pressure condition that the system must overcome – which greatly reduces its efficiency. In other words, the exhaust system has to work much harder, is less effective resulting in increased operating costs. It not only has to push exhaust air out of the building but also has to pull fresh air into the building (infiltration).


  1. Backdrafts down furnace flues reduces heating system efficiencies and releases products of combustion into the work area and often destroys the heating equipment.
  2. Cold drafts are created at the floor level. These drafts are uncomfortable for workers and interfere with hood exhausts and process equipment.
  3. As the cold air rushes across the floor toward the exhaust fans, it activates the thermostats. The heating system is called on to heat this cold air. But because hot air is lighter than cold air most of the heat rises back to the ceiling before it can heat the cold air at the floor. This causes even higher temperatures at the ceiling which increases the amount of BTU’S lost through the roof.
  4. Heating costs are unnecessarily high.
  5. Doors can be difficult, and often hazardous, to open or close.
  6. The amount of air removed from the building by the exhaust fans will be significantly reduced causing insufficient ventilation for air contamination control.
  7. Cold zones around the inside perimeter of the building caused by infiltration which effectively reduces usable floor space due to employee discomfort.


The historic method of introducing make-up air into a building is through a heated system. This will eliminate some of the problems caused by a negative pressure but it has several drawbacks.

  1. Fired make-up air increases the amount of wasted heat at the ceiling, therefore increasing the rate at which it is transmitted and lost through the roof.
  2. Most make-up air systems dump large quantities of air in one general area. This can cause drafts and in Many cases leaves large portions of the plant without fresh air.
  3. Dead air spots result because of the lack of uniform distribution.

The Benefits of  the patented EnergyMaster® MakeUp Air Equipment

  • Converts a Heated Makeup Air Unit to an Effective Summer Ventilation System, Distributing MakeUp Air Evenly Throughout the Building
  • Uses No Fuel
  • Can Pay for Itself in Less than One Heating Season
  • Converts Existing Make-Up Air System to Use the Otherwise Wasted Heat Stratified at the Ceiling
  • Cools & Ventilates in Summer

Click Here to See How EnergyMaster® Works

Click Here to See How SeasonMaster® Works


Erik Hall


Johnson Controls

After the installation of more than twenty of your EnergyMaster Units with SeasonMaster Tuff Ducts, we now have the ability to control and direct the airflow where we desire,.........The employees let us know right away if we forget to turn your systems on.


After the installation of (3) units with SeasonMaster Tuff Ducts at are new plant, we now have the (Sumer/Winter) capability to control and direct the airflow. We now can utilize stratified heat during the winter and we have a summer ventilation system during the hot weather. We appreciate and thank you for the strong support and expertise for all these years.


EnergyMaster is our make-up air unit of choice an we have not bought a gas-fired make-up air unit since installing the first EnergyMaster. I am pleased to say that we still run all eight original units.......


We installed a total of seventy-two EnergyMaster unheated make up air systems in a number of our plants across the United States. It turned out to be the perfect solution........... my sincere gratitude for their assistance helping us complete this large project in such a smooth, efficient and timely manner.


........it became evident the EnergyMaster System, with the SeasonMaster Air Direction Controller, is the best way to introduce make-upair as well as providing summer ventilation.


The SeasonMaster system allows the make-up needed during the winter without additional fuel cost with the added benefit of spring/fall ventilation. SeasonMaster System was our choice to other fabric duct socks and sheet metal ducts.