MAKE-UP AIR UNITS

AIR-JET systems are utilized in buildings requiring the replacement of air having been evacuated through general ventilation or source extraction fans. Without this compensation of fresh air, the building would be maintained under negative pressure which diminishes the efficiency of ventilation systems, accelerates the infiltration of cold air drafts which causes very uncomfortable working conditions, namely hot and cold spots along with very uneven temperatures between ceiling and floor levels.

AIR-JET units are available in six standard sizes and two standard configurations, each comprising a galvanized steel housing, single or dual dampers, an axial fan/motor assembly and a polypropylene air duct. A typical installation would require an exterior wall intake hood or roof intake hood along with companion ducting to complete the installation.

AIR-JET Models

AIR-JET units are available in two distinct configurations, each satisfying a particular requirement.The varying designs allow the AIR-JET units to meet most installation demands.

Model FA (100% Fresh Air)

This unit possesses a single motorized damper on the rear of the unit, which serves to allow fresh air to enter the fan unit when functioning or to inhibit infiltration when the unit is off. The fan motor and damper motor are controlled by a customer supplied and installed starter, which is normally at the floor level. If required, the customer can interconnect the AIR-JET system with other exhaust systems. Units are completely prewired and require only primary electrical connection. The two position damper motor (open or closed) is equipped with an emergency return function to ensure this damper closes during a power outage. The FA unit brings 100% fresh air into the building and thus would be selected when there is an abundance of hot air available to offset the incoming air during winter operation.

Model FA-R (Fresh Air and Recirculation)

The FA-R unit is similar to the FA unit with the following exceptions. A second mixing or recirculation damper (Y) is provided within the fan cabinet. The two dampers (X and Y) are interconnected and controlled by a modulating damper motor and proportional electronic thermostat. (Thermostat is located on the fan housing if not otherwise requested). Unlike the FA model which can take air only from outside, the FA-R unit can mix fresh outside air with warm inside air before being distributed in the building through the air tube. The FA-R unit would thus be selected where some tempering of outside air is required before discharge into the building environment. Units are completely prewired and require only primary electrical connection. Emergency return of the damper motor to the closed (shut) position is provided.

Principle of the system

The principle of the system is quite simple: hot air trapped at the ceiling within your building is used to preheat fresh air being forced into the building by way of the AIR-JET unit. Under normal circumstances the hot air trapped at the ceiling goes unused and consequently is lost right through the roof. The AIR-JET systems have a net advantage over conventional make-up air units in that their initial purchase price is much lower and of equal importance is that their operating costs are drastically reduced in that they burn no gas or oil but utilize “existing or free” heat available in the building.

SPECIFICATIONS:

Housing
Construction is 16 gauge galvanized steel. The housing is equipped generally with two access doors giving simple access to the units’ components which may require attention. Electrical terminal box is located on the outside of the fan housing providing easy access for electrical hookup, controls or maintenance.

Fan
An axial fan is employed in standard units, both statically and dynamically balanced to ensure proper operation. The fan blade sits on two industrial quality pillow-block bearings. High pressure applications require an optional blade which can be made available at an additional cost.

Motor
Continuous use TEFC motors are used wherever practical. Available voltages are 115/230/1/60 or
208/230/460/575/3/60 for 1/3, 1/2, 3/4 or 1 HP motors. Available voltages are 208/230/460/575/3/60 for 3, 5, 7.5 HP motors.

Motorized Dampers
Constructed of industrial quality galvanized steel, the fresh air damper provides minimum leakage with gap seals. Optional insulated air foil dampers are available at an additional cost.

Tube

AIR-JET air discharge tubes are fabricated to meet each individual application. Constructed of high density polyethylene fabric which is coated on both sides, this material meets government self-extinguish requirements. Tubes are perforated as required and available in standard configuration or dual mode (summer/winter).