Double Skin Air Handling Unit

The Double Skin Air Handling Unit is an integrated piece of equipment consisting of fans, heating and cooling coils, air-control dampers, filters and silencers. Air Handling Units are often called AHU. The purpose of this equipment is to collect and mix outdoor air with that returning from the building space. The air mixture is then cooled or heated, after which it is discharged into the building space through a duct system made up of five-feet diameter pipes. Air Handler is normally associated with heating/cooling (HVAC) systems in commercial buildings. These are normally very large systems moving 2000 CFM to 10,000 CFM and higher. They may be mounted on the top of the roof or in large mechanical rooms located in the building. They often have an economizer or inlet damper that allows for a small amount of fresh air  or make-up air to be pulled in through the air handler.

Double Skin Air Handling Unit is a one piece equipment and easy to transport as well as install at site. Means lower installation cost. Slotted mounting brackets facilitate easy above ceiling installation as well. Scanair double Skin Air Handling Units manufactured in a quality range with airflow varying from 1000 cfm – 30000 cfm an up to 150 mm total static pressure with following salient features

Frame Work

The frame work comprises an assembly of extruded aluminium profiles and 3-D nylon glass filled reinforced corner joints. Double Skin sandwich panels are fabricated from inside with 0.65 / 0.8 mm G.I./AL./ S.S sheet steel and outside with 0.63 / 0.8 mm thick coated galvanized sheet steel with guard film. The panels are polyurethane foam injected with density 40 kg/m3, having thickness of 25 mm and 50 mm resulting in high rigidity and sound attenuation characteristics. Entire unit is mounted on extruded aluminum channels or galvanized legs.


Fan section is designed for housing DIDW forward curved / backward curved centrifugal fan dynamically balanced.

Pre Filter Section

Pre filter section is designed for housing 48 / 50 mm thickness filters. Filter section is provided with access door panel with imported aluminum die cast powder coated heavy duty hinges and nylon handles. The pre filter frame can also be mounted directly on face of the Air Handling Unit (Return air side). Effective HVAC filtration is at the heart of Indoor Air Quality (IAQ).  It provides an important service in keeping indoor environments clean and free from the dust and particulates that may reduce productivity, affect the health of building occupants or cause other potential problems.  However, it is to be remembered that filters will only support good IAQ and perform as specified when they are maintained correctly.

Proper filter maintenance is crucial in keeping HVAC duct work clean. If dirt accumulates in the duct work, and if the relative humidity reaches the dew point so that condensation occurs, then it can become a breeding ground for bacteria and mold.

High Efficiency Filter Section

High efficiency filter section is designed for housing 300 / 500 mm thickness Hepa / Bag / Microwave filters. Filter section is provided with access door panel.

Double Skin Air Handling Unit for pharmaceutical applications

In all pharmaceutical manufacturing applications, particulate contamination is un acceptable. There fore, it is important to include filters in the makeup air system in addition to the filters located in the main air handling system.  Makeup air not only is a great source of moisture, but it is also a great source of particulate contamination. Scanair recommends that 30% efficiency pre-filters and a minimum of 55% efficiency final filters be located at the intakes of the makeup air and the system in order to reduce the amount of particulate that enters the system.  In addition, 30%, 55%,or 95% filtration should be arranged in series at the outlet of the system.  This will eliminate any residual particulate or dust from any upstream components.  HEPA filters can be placed at the end of the system in order to capture smaller particles located in the air stream prior to that air stream entering the conditioned space.

Double Skin Air Handling Unit for Biomedical applications

HEPA filters are critical in the prevention of the spread of airborne bacterial and viral organisms and, therefore, infection. Typically, medical-use HEPA filtration systems also incorporate high-energy ultra-violet light units to kill off the live bacteria and viruses trapped by the filter media. Some of the best-rated HEPA units have an efficiency rating of 99.995%, which assures a very high level of protection against airborne disease transmission.

Coil Section

Coils are also computer selected to obtain optimum psychometric efficiency with low air and water or direct expansion or hot water coils are constructed from copper tube hydraulically / mechanically bonded to aluminum fins. The coil assembly complete with header is fitted on aluminum rails and nylon rollers for easy with drawl from either sides.

Drain Pan

Drain pan is fabricated from 1.6 mm (16g) aluminum and 1.25 mm (18g) stainless steel sheet having uniform slope from all sides for zero water retention. Entire assembly is mounted on insulated bottom panel.

Fan Section & Motor Assembly

Fan and motor assembly is mounted on base frame constructed of aluminum extruded profile / galvanized sheet steel. The frame assembly is isolated from the rest of the general structure with anti – vibration spring isolators and fire retardant flexible canvas connection fitted on fan discharge.

Double Skin Air Handling Unit Application Areas

Double Skin Air Handling Unit is widely used in Bio medical labs, Printing Industries, Hospital Operation Theaters, ICU areas, Medical Equipment , MRI rooms, CT& Pet Scan Rooms, Pharmaceuticals, Laboratories, R & D Labs.

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