Note:Hose clamps are not recommended because the duct-ing can detach from the ring. ?Do not crush or kink any ducting as this will restrict air flow. ?Ducting can be reformed to fit odd-shaped spaces, but must be done socarefully in order to prevent restrictions.Ducting can be easily reformed on the ends to fit oval rings.?Insulated ducting should be used when routed in high ambient temperature locations.Make certain the inner liner is routed in a smooth manner to avoid restrictions.

Installation Guidelines for Ducting & Transition Boxes

When choosing the proper size transitions and duct work for any system, pri-mary consideration should be given to the capacity of that system, along with its required air flow (CFM).Reduced or restricted air flow due to undersized transi- tions and ducting or improper installation will result in loss of performance and/orinefficient operation of the system.Distribution boxes for air flow are constructed of insulated aluminum or vacu-um formed plastic.A variety of configurations are available for air distribution, including enclosed boxes (which fit directly onto blower assemblies), remote boxes (to distribute air flow from the unit to other areas), and transition boxes (to distrib- ute air into areas through grilles and into other boxes).Unit boxes are to be attached directly to the blower outlet.The mountingplate is attached to the blower flange and the box is attached to the plate.This box should be positioned in such a way as to provide air flow through the duct work with as few bends as possible.On most units, a rotatable blower allows for further flexibility in proper positioning of the box.Remote boxes are to be secured to any solid shelf or bulkhead.The ductrun from the unit to the box should be as straight as possible.From the remote box, properly sized ducting is to be installed into each area based on the air flow (CFM) required.Transition boxes are to be located as high as possible in any cabin area toprovide even air circulation and temperatures.When this location is not possible, transition boxes are to be installed in such a way as to channel air flow up and across any area.Grilles with directional louvers or built-up wedges may be neces- sary to accomplish proper air circulation, louvers should point upward.Transition boxes are designed to accept ducting (via transition rings) oneither side, end or on the back.Side or end installations should provide pressuriza- tion of the box, allowing for a full, even flow of air across the entire surface of the attached grille.Back installations should provide higher air velocity through theattached grille, with less pressurization or full flow across the entire grille surface.Proper installations will prevent air leaks.If problems arise due to location ormounting surfaces, strips of adhesive-backed foam can be applied to fill gaps. Caulking or other adhesives are not necessary and should not be used.A variety of baffles and restrictors can be applied to divert air flow as necessary to ensure adequate CFM to any given area.Consult Marine Air Systems for specific applications.Flexible ducting is designed to offer optimum routing throughout vessels.Thefollowing guidelines will ensure proper application and performance:?Route all ducting in a smooth, taut and direct manner.Avoid hard bends(90°or more) whenever possible.Cut off any excess length.?Secure all ducting in place, as vessel motion can cause sagging or shifting which may result in reduced or restricted air flow.?Compress 2 or 3 wraps of the spiral reinforcing wire of the ducting on tothe ring.Secure the ducting to the ring with 3 or 4 screws above the com- pressed wire wraps.This method prevents the ducting from slipping off of the ring.

Letters denote location of rings when ordering boxes.See order form found in Direct Expansion Price Schedule.

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ENCLOSED BOXENCLOSED TRANSITION DUCTINGTOFIT UNITREMOTE BOXRINGS

In the interest of product improvement, specifications and design as outlined herein are subject to change without prior notice.

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