Features & Options

Size Range

  • Unit sizes range from 2,000 to 100,000 CFM or more.

Operating Pressures

  • Low and high pressure construction up to 12″ w.g.


  • Standard 2″ deflection seismic vibration isolation.

Modular/Unibase Construction

  • Indoor/Outdoor units.

  • Outdoor mounted air handlers with full length service vestibules.
  • Factory installed piping and controls for single source responsibility.

  • Double-deck multizone units.

  • Factory pre-assembled modular construction or knocked-down for field assembly.

Casing Construction

  • Units are available in galvanized steel, stainless steel or aluminum, with solid or perforated liners.
  • AgIONTM coated internal liners.


  • Sturdy construction is assured with 2″ or 4″ thick acoustical panels for indoor and outdoor applications.

  • Acoustical performance of air handler panels is tested by an independent laboratory.

  • Units are available with complete sound attenuation packages.


  • Thermal break construction is available as an option.

  • The insulation may be protected with an optional Tedlar® film wrapping.

HVAC Design

  • Wide selection of options includes: factory mounted heat recovery, gas fired heating, electric coils, DX systems, controls and power packages for single source responsibility.

  • Cooling coil sections are complete with dual sloped stainless steel drain pans. Stacked coils include intermediate drain pans. Stacked coils are rack mounted and individually removable.

  • High efficiency and electronic filtration systems.
acoustic features and options

Fans and Motors

  • Internally mounted motors with a complete choice of fan types: centrifugal, tubular, axial, plenum, and others.

Paint and Finishes

  • Standard finish is high quality polyurethane copolymer.
 Completely washable hospital/clean room units with stainless steel, aluminum or AgIONTM liners.

FDA and Pharmaceutical Design

  • Totally uniform inside surface minimizing fasteners in the air stream.

  • Stainless steel, aluminum or AgIONTM liners.

  • Sloped floor for complete drainage.


Racan Carrier air handlers are designed using proven structural principles. Standard cabinets are constructed with G-90 galvanized steel unless otherwise specified. All frame members are sized for the highest possible dynamic and static loads.

ACOUSTAIR® units with 4″ thick walls are suitable for pressure differentials up to 12″ w.g. static pressure.

ACOUSTAIR® units with 2″ thick walls are suitable for pressure differentials up to 8″ w.g. static pressure.

acoustic features and options


The base frame is specially designed to ensure maximum rigidity during lifting and handling. The perimeter base channel is designed for a deflection of less than 1/300 of the longest module dimension.  Intermediate channels and structural supports are spaced at regular intervals and located to support heavy loads such as integral bases and coils. For rigging purposes, the base is supplied with lifting lugs on each side. The lifting lugs are bolted to full 3/8″ thick carbon steel backing plates.Three options are available for the perimeter base frame.The figure illustrates these options.Type 1 is the standard perimeter; the cross section consists of a double heavy -duty formed galvanized steel channel. The longitudinal and angular perimeter segments are mechanically fastened to form a sturdy support frame. The perimeter is consistently and completely insulated.For applications where it may be deemed necessary to include a structural C-channel, base type 2 is an available option. The design concept is the same as base type 1.


Floor types 1 and 2 are standard floor details. Type 2 is used in cases where additional rigidity is needed. The floor surface is 16 ga. galvanized steel. Sectional floor joints are sealed to form a watertight drainable floor throughout the unit. 1 1/2 inch drain connections can be installed in any of the air handler sections.

The floor frame consists of a heavy -duty structural support grid made of formed galvanized steel channels at 16” center-to-center intervals.

The floor is thermally insulated with 2” and 4” fiberglass media according to the wall cabinet thickness. The insulation is protected from underneath with G-90 galvanized steel under-floor liners.

Floor types 3 and 4 have the same basic features as 1 and 2, but in addition the floor surface is recessed into the floor support grid by 2 inches. The floor depression provides additional water containment volume.

Floor types 5 and 6 offer the best possible indoor air quality wash-down feature : floor surface is recessed into the floor grid by 2” and in addition, the floor is sloped 1” to one side of the unit to ensure positive floor drainage. Floor drains can be installed in any air handler section. This type of floor is available with 4” insulation only.

acoustair floor surface feature


To minimize sound and air leakage the “single leakage path” was adopted to assemble the wall and ceiling panels. Rigid intermediate T-Mullions are mechanically fastened to adjacent panels. See figures 6, 7 and 8.

Cabinets are designed for minimum deflection at the highest possible operating pressure. Panel widths vary depending on operating pressure, material type and specific application conditions.

Wall and ceiling panels are reinforced with internal galvanized steel stiffeners installed horizontally and at regular intervals. The spacing between the stiffeners is determined by the operating pressure and the combination of panel width and height. Panels are externally sealed with a visible bead of polyurethane caulking compound.

Reduced conductivity “thermal break” option is available. Closed cell neoprene gaskets are applied between panels to reduce thermal bridging.

acoustair access doors feature


Access doors are designed for maximum airtightness, high acoustical performance and esthetically pleasing finish. High quality durable doors provide easy access for maintenance of the air handlers. Door frames are made out of a single piece galvanized steel sheet with rounded corners to provide a mounting surface for a single gasket. Doors are 2” or 4” thick double wall construction, filled with acoustic media and G-90 galvanized steel skins. Door gaskets are neoprene heavy -duty type. The gaskets are mounted onto the door frame by means of a self-gripping mechanism hence providing a long service life without loss of airtightness. Doors are equipped with a minimum of two heavy -duty hinges and two sturdy handles. For safety reasons, handles can be operated from both sides. Standard doors open against the higher pressure side. As an option, thermal dual pane inspection windows can be provided (not available on doors with free opening width of 14”).

For more information on door sizes and free opening dimensions, see page 68.

Optional thermal break design includes dual door gaskets. See figure 5.


Access panels are used on blow-thru coil sections and on sections with restricted space. They are 2″ or 4″ thick double wall construction filled with acoustic media and built with heavy gauge galvanized steel for high acoustic performance. A heavy -duty automotive type neoprene gasket self-gripping either on the frame or panel perimeter ensures airtightness and long service life.


Racan Carrier air handlers are offered with a variety of panels and two acoustic media thicknesses. All panels are designed to resist deflection or bowing. The acoustic media has long resilient inorganic glass fibers, is non-flammable and is bonded with a thermosetting resin.

The ACOUSTAIR® 4″ thick acoustic panel (perforated galvanized steel interior, galvanized steel exterior) provides the highest sound absorption. The acoustic performance of this panel, as tested by an independent laboratory, is the following:

acoustair choice of insulation feature

Sound absorption tests conform explicitly to the requirements of the ASTM standard method for sound absorption coefficients by the “Reverberation Room Methods” ASTM C423-90a and E795-93. Sound transmission loss tests were conducted in explicit conformity with the ASTM designations E90-90 and E413-87.

Acoustical panels are also available with a protective Tedlar® wrapping to provide additional protection against fiber erosion. This offers an ideal option for sound critical applications with high indoor air quality standard.

Double wall panels, complete with acoustic media and galvanized steel liner on both sides, provide high sound transmission loss and ensure the highest protection against fiber erosion.

The thermal properties of the acoustic media are the following :

acoustair choice of insulation feature
acoustair wash down duty panels features


This type of double wall panel has a smooth inside surface suitable for wash down applications. Interior liners can be stainless steel (304 or 316), aluminum, or AgIONTM coated steel liners. With this option, the unit floor is sloped to ensure complete drainage. This type of panel meets the highest standards encountered in food, FDA, pharmaceutical, and other industrial applications. It also is the ideal choice for bacterial or fungal control.


AgIONTM coated metal offers the possibility of suppressing the growth of microbes on the large inside surfaces of the air handlers. While this Carrier innovative option does not replace routine cleaning, the coating can be an effective tool in buildings such as schools, hospitals and nursing homes where there is heightened concern about microbial growth. By selecting this option, the air handler liners, standard 16 gauge floor and T-Mullions shall have a visible blue AgIONTM coating.


As an option, UV-C germicidal lamps can be provided and installed downstream of cooling coil sections. The high output UV-C energy from the UV-C lamps attacks targeted fungus, mold, bacteria or virus at the cellular level, preventing replication and causing cell death. By-products are harmless amounts of CO2 and water. These new Carrier HVAC duty UV-C accessory germicidal lamps are the best form of biofilm source control for HVAC units. The lamps are generally installed 1 foot away from the target (downstream of the coil surface) and require 10 square feet of target surface per lamp.


The blower section is built according to project specifications and, as a standard, is supplied with an internal motor and internal vibration isolation. A wide access door on the drive side allows for easy servicing and motor removal. Side panels can be disassembled for complete fan removal without affecting the structural integrity of the cabinet. Fans with W and Z motor positions are centered within the casing for best aerodynamics and performance. For special applications, X and & Y motor positions are also offered.


Racan Carrier air handlers are supplied with factory mounted motors.

Double adjustment motor slide bases provide for proper alignment and belt tension adjustment. Unless otherwise specified, motors are standard efficiency, 1800 RPM, open drip-proof (ODP) type and of manufacturers selected by Racan Carrier. Other types of motors are available upon request.


Integral bases with 2″ deflection seismic isolators and flexible connections provide full vibration isolation of fan and motor assembly. When required, neoprene mounting thrust restraints are supplied for stable operation and to protect the flexible connection from tearing.

acoustair internal isolation features


As energy costs continue to spiral upwards, it is becoming increasingly important to maximize the efficiency of air handling systems. Racan Carrier air handlers meet this challenge by using high quality AMCA® certified fans.

Figure 13: Cooling coil drain pan

Backward inclined and airfoil centrifugal fans as well as backward inclined and airfoil plenum fans are available. Plenum fans are available up to class III construction and centrifugal fans up to class IV.

All fan wheels are dynamically balanced and the entire fan is again trim balanced after assembly to ensure smooth operation. Three vibration readings are taken on each bearing in the horizontal, vertical, and axial directions. Then, vibration amplitude is plotted versus the frequency. The data becomes a permanent record and can be retrieved for future reference via the fan serial number. Self-aligning pillow block bearings are also available. Fan housings are provided with airtight lock seams or continuously welded construction. Rigid support members provide a heavy -duty structural strength frame.

Belt guards and inlet screens are offered as options. Due to the open characteristics of the plenum fans, they can be supplied with optional protective enclosures.

Centrifugal fans are installed in accordance with the standard AMCA® arrangements (W, X, Y, and Z motor positions), therefore giving ample space for maintenance of opposite drive side bearings.

Lube lines are available to lubricate both bearings from one side within the casing. Extended lube lines to casing exterior are also available as an option. Plenum fans must have an access section upstream of the plenum fan section for maintenance and uniform air distribution. For fan performance curves and sound data, consult the fan manufacturer’s catalogues or contact your local Racan Carrier representative.


Perforated baffles are standard in blow-thru coil sections to provide uniform airflow over the coils. They are installed downstream of centrifugal fan discharge and upstream of coil, filter or sound attenuator section.


Draw-thru cooling coil sections are furnished with one or more I.A.Q. stainless steel double sloped drain pans. An intermediate drain pan is supplied on stacked coil applications. This section is supplied with 1.5” O.D. brass drain sweat connection. Secondary drain pans have a 1” diameter vertical drain pipe cascading condensate to the main pan. Each sectional drain connection is designed for a maximum of 1.8 gpm water flow.

Air handlers with cooling coil areas greater than 64 square feet have two (2) or more drain connections. The coil sections include galvanized steel blank off sheets to hold the coils rigidly and prevent air bypass. All joints between the blank off sheets and the cabinets are caulked.

Coil headers, refrigerant distributors and return bends are completely enclosed within the casing. All piping connections, except refrigerant distributor line, extend through removable panels with rubber grommets to prevent air leakage. Removable panels are heavy gauge double wall with 2” thick insulation. They are gasketed and bolted. Coils are mounted on independent racks and are individually removable.

For maximum flexibility, cooling and heating coil sections are available with the following coil mounting options :

1. The standard coil section arrangement features single, double and triple coil high with their respective individual coil piping connections extended through the cabinet wall.

2. Split coils with coil piping connections extended through the cabinet wall on both sides.

3. Horizontally split and staggered coils with coil piping connections extended through the cabinet wall on the same side or on the opposite side. This arrangement allows for coil removal on the same side. It minimizes coil pull area required.

4. Horizontally split, staggered and overlapped coils with coil piping connections can be extended through the cabinet wall on the same side or on the opposite side. This arrangement minimizes the coil section width and moderately increases the section length. It also minimizes coil pull area and increases coil face area.

5. Vertically staggered and overlapped coils with piping connections extended through the cabinet wall on the same side. This arrangement minimizes the coil section height and moderately increases the section length. It also minimize coil pull area and increases coil face area.

Detailed information about coil arrangements can be found from page 39 to page 52.

acoustair Draw-thru cooling coil section features


Electrical heating coil sections are available with on-off, multi-stages and SCR controlled stages. Safety airflow switch, high temperature limit and fused/unfused disconnect switches are included with the basic package.


This section has the same features as the cooling coil section without drain pan and drain connection.

acoustair Blow-thru dual duct multizone coil section features


This section combines a cooling and a heating coil in a double-deck configuration. It always includes a perforated diffuser at the fan outlet to provide even airflow across the coils.

For maintenance purposes, the blow-thru section is supplied with two access panels that permit access to plenums upstream and downstream of the cooling coil.

The cooling coil is furnished with a stainless steel double sloped drain pan for positive drainage. A 1.5” O.D. brass drain connection is provided as standard. Racan Carrier air handlers can accommodate a maximum cooling coil casing depth of 12.5”.

The coil sections include galvanized steel blank off sheets to hold coils rigidly and prevent air bypass. The heating coil is mounted in the upper deck in an inclined position for proper air distribution across the entire face area. The hot deck can accommodate a maximum coil casing depth of 10”.

Both coils have their headers, refrigerant distributors and return bends completely enclosed within the casing. Piping connections extend through removable panels with rubber grommets to prevent air leakage. Removable panels are heavy gauge double wall with 2” thick insulation. They are caulked and bolted. Coils are rack mounted and are individually removable from multiple coil sections.

Optional zone dampers for multizone system are available to provide air mixing directly at the unit discharge. Damper blades are parallel acting within individual partitions to provide smooth and accurate temperature control. Hot and cold deck dampers are locked together at 90 degrees on a common shaft, so each zone goes from full cooling mode to full heating mode with a quarter turn shaft rotation. Shaft extensions are available on either the cold or hot deck side.

Note: Due to transport and field limitations, cold deck, hot deck and zone dampers may be shipped separately for field re-assembly.


To provide maximum flexibility, Racan Carrier offers four standard coil face area sizes (small, large, extra-large, and hot deck) on all air handlers, hence permitting the selection of the most economical heat transfer surface.

Coils installed and used by Racan Carrier offer a large variety of fin spacings, rows, and circuiting combinations, thus permitting to accurately meet load requirements.

Coil performances are certified in accordance with ARI standard 410. To select the most efficient coil, contact your local Racan Carrier representative.

Standard coil construction includes galvanized steel casing, aluminum fins, and 5/8” diameter copper tubes. Water coils also have copper headers, steel male pipe connections, a vent connection at the highest point, and a drain connection at the lowest point. Steam coils have headers, steel male pipe connections, and are sloped in their respective casing to ensure positive condensate drainage. Refrigerant coils have brass liquid distributors and sweat copper suction connections.

As an option, tubes, fins, and casings can be of special materials and thicknesses. Contact your local Racan Carrier representative for availability.

acoustair coils features


Side loading flat filter sections have access doors on one or both sides. Each door has sturdy hinges and latching mechanisms.

Filter sections include extruded aluminum channel filter guides suitable for side loading of filters. Filter channels accommodate 2” or 4” thick standard panel filters.

Front or rear loading flat filter sections do not have side access doors but include holding frames suitable for front or rear loading accordingly.


Angular filter sections have an oversized face area to extend the filter life. Access doors are provided on one or both sides. Each door has sturdy hinges and latching mechanisms.

Filter channels accommodate 2” or 4” thick standard panel filters.

acoustair Angular filter section features
acoustair High efficiency filter section features


High efficiency filter sections can be provided either with side access or front loading. Side access has access doors on one or both sides of the section. Each door has sturdy hinges and latching mechanisms. Front loading requires an adjacent access section for servicing; it becomes mandatory for HEPA filters. A high efficiency filter section can also be installed in a blow-thru arrangement for final filtration applications.

Holding frames and aluminum filter racks are factory installed. The basic section can accommodate 2” or 4” thick pre-filters and up to 22” deep final bag filters. If longer filters must be used, a spacer section of appropriate length must be added downstream.

Pre-filters and final filters are of standard dimensions:12” X 24” and 24” X 24”.


This accessory section provides a simplified means of modulating any desired ratio of fresh and return air. Dampers use parallel acting blades that are positioned to direct the airstreams into a merging pattern thereby reducing air stratification.

However, a mixing box does not eliminate air stratification. To prevent water coils from freezing and/or low temperature cutouts, special consideration must be taken when the fresh air temperature is below freezing point.

To enhance air mixing, the system designer should specify an air blender section. The use of water/glycol solution in the coils will further reduce the possibility of coil freezing.

Optional doors are available for servicing or to permit access to an adjacent section.

Dampers and their driving rods are normally installed outside the casing. As an option, they can be installed inside. In this case, an access door is mandatory.

acoustair Mixing box features
acoustair Combination angular filter and mixing box features


This compact arrangement combines the basic characteristics of a mixing box and an angular filter section in a space saving configuration. Low temperature outside air applications require special consideration.


The economizer section is a combination of two mixing boxes in a more compact assembly. It permits an accurate modulation of fresh air, return air, and exhaust air.

Standard mixing box characteristics and options are offered for this section as well. The damper face area sizing and the use of a perforated plate at the inlet of the recirculation damper allow a more linear relation between damper blades’ position and airflow.


This basic arrangement combines the characteristics of an economizer and an angular filter section in a space saving configuration. Basic options are available.

acoustair Combination angular filter and economizer features


A face and bypass damper section is offered to modulate airflow across a coil. Its use is limited to small face area coils. Dampers are opposed blade type to provide even airflow across the coil surface. Driving rods are normally extended outside the casing although the actuators can also be installed inside. In the latter case, an access in the upstream section is mandatory.

acoustair External face and bypass features


This longer section is offered to modulate airflow over large and extra-large coils. Duct bypass may be factory mounted or field installed. Dampers are opposed blade type to provide even airflow across the coil surface. Driving rods are normally extended outside the casing although the actuators can be installed inside. In the latter case, an access in the upstream section is mandatory.


A full face damper section is offered for systems that require isolation when in shutdown mode. Dampers are opposed blade type and can be optionally insulated. Driving rods are normally extended outside the casing, although the actuators can be installed inside. In the latter case, an access in the upstream section is mandatory.


All dampers, including multizone, are low leak type with a leakage rate of less than 1 % for parallel blades and less than 0.6 % for opposed blades, both at 8” static pressure differential. The dampers are extruded aluminum airfoil blades and have hexagonal driving rods stamped in the blades. The blade linkage hardware is installed in the damper frame out of the airstream. As an option, Racan Carrier offers dampers with thermally insulated blades.


Racan Carrier offers an air blender section to reduce air stratification downstream of a mixing box or a face and bypass section. A 75 % efficiency air mixer section allows a large volume of fresh air. The following formula gives the maximum outside air volume to maintain the air temperature above 35oF at any point along the air mixer section discharge:

Max. % fresh air = 0.88TR + 0.12TO – 35 x 100 %

TR = return air temperature (oF)
TO = outside air temperature (oF)

Air blenders are static devices that do not require maintenance. However, an optional access door is offered for access to a downstream section.

acoustair Air blender features
acoustair Air blender features


Sound attenuator sections can be provided within the air handlers. Contact your local Racan Carrier representative for further information.


Where required, access sections allow for service of internally mounted components. For example, they are often installed between coil sections and upstream from a front loading filter section.

Four section lengths are available :

  • 23” Small (14” net opening)

  • 25” Standard (16” net opening)

  • 29” Large (20” net opening)

  • 35” Extra-Large (26” net opening)
acoustair Access features


Figure 27 illustrates the standard humidifier section. The nominal section length is 48″ with 12″ space upstream of the humidifier dispersion tubes and 36″ downstream for vapor absorption distance. These lengths can be modified as required by a specific humidifier selection. The floor includes a full galvanized steel drain connection. An access door is required within the section or downstream of it. The dispersion tubes may be installed at the factory. The humidifier section can accommodate all brand name humidifiers. For available space within the humidifier section, refer to the dimensional data.


Spacer sections can be of any length. They can accommodate special accessories that can be field or factory installed. Removable panels can be provided on one or both sides. They are of heavy gauge double wall construction with 2″ or 4″ thick insulation.

Space limitations dictate the maximum dimensions of special equipment that can be incorporated within this section. For 4″ walls, the overall dimensions must be at least 12″ shorter than the unit height, 10″ narrower than the unit width, and 6″ smaller than the spacer section length.

When factory installed, special equipment is properly blanked to prevent air bypass. However, when it is field installed, blanking must be done on the job site by the contractor.

acoustair spacer features


This section is designed to accommodate vertical integral face and bypass coils from various manufacturers. The space available for a given unit size may be evaluated by referring to page 58. When using steam coils, always evaluate the space required for steam trapping. Generally, 18” head is required for proper condensate flow and trap installation.