Air Turnover Systems

IFP: Indirect Fired Air Turnover · IFA: Indirect Fired Heat/Cool · IFS: Slave Unit for Indirect Fired · IFJ: Indirect Fired for Small Spaces

Unique floor mounted heating and cooling units

Low Velocity Air Discharge

Low Velocity Discharge

In heating mode, air is discharged directly at low velocity. No ductworks is required so installed cost is lower.

Variable Control Power Burner


Power burner features direct spark ignition, on-off, high-low, and modulating controls.

Direct drive induced draft fan

Induced Draft

Direct Drive induced draft fan on IFP helps provide gas heating efficiency of up to 80%

Single point of control

Control Cabinet

Fuses and power transformer are provided for single point electrical connection

Low velocity propeller fans

Low Velocity Fans

IFP, IFS, and IFJ use propeller fans

Heating Mode

Air Turnover system in heating mode

The Air Turnover System picks up the air at the floor, where it is the coolest, then heats and returns it to the space above. Innovative low velocity, low horsepower propeller fans gently turn over the room air 1 to 3 times each hour to maintain uniform temperatures from floor to ceiling throughout the building. Cold air from open doors in shipping and receiving areas becomes less of a problem with an Air Turnover unit. Temperature recovery is almost instantaneous after the doors are closed.

Cooling Mode

Air Turnover system in cooling mode

The Air Turnover System picks up air at the floor then cools and returns it to the space above. A comfort zone is created from the unit discharge down to the floor level. For buildings requiring cooling from floor to ceiling, extensions are available to get the unit discharge to required height. The centrifugal fans quietly move large volumes of air, turning over the air in the comfort zone 3.5 to 5 times each hour.

Air Turnover Unit

In a building with high ceilings, such as a warehouse or manufacturing facility, thermal barriers are established as warm air rises and gets trapped at the ceiling. The result, known as "air stratification," creates layers of temperature in the space.

The temperature at the ceiling may be 25 degrees hotter than at the floor, and the heat trapped at the higher level is unusable. Since the desired building temperature must be maintained at a low level, the inevitable result is excessive heating bills.

Air stratification also creates problems in spaces that require cooling. Because cool air settles to the floor, higher levels remain too warm. When the temperature is not uniform from floor to ceiling, condensation can form causing moisture damage.

An Air Turnover system solves the air stratification problem by continuously circulating the air in the space. It picks up air at the floor, removing the coldest air layer supporting the thermal barrier. The air is heated or cooled, and returned quietly through a screened discharge plenum to create a uniform temperature and a comfortable, more cost-effective conditioned space.

The Air Turnover principle eliminates air stratification in large open space buildings. It does this by recirculating the hot air which becomes trapped at the higher levels. The uniform room temperature improves comfort, conserves energy, eliminates thermal barriers, and eliminates the possibility of condensation forming on stored materials.

The Benefits and Features of Air Turnover Systems from Applied Air

Anatomy of an Air Turnover HVAC System