Bard WH612 Installation Instructions Manual

Manual 2100-480Page 7 of 24FIGURE 2FRESH AIR DAMPERDesign the duct work according to methods given by theAir Conditioning Contractors of America (ACCA).When duct runs through unheated spaces, it should beinsulated with a minimum of one inch of insulation.Use insulation with a vapor barrier on the outside of theinsulation. Flexible joints should be used to connect theduct work to the equipment in order to keep the noisetransmission to a minimum.A 1/4 inch clearance to combustible material for thefirst three feet of duct attached to the outlet air frame isrequired. See Wall Mounting Instructions and Figures4, 5, 6 and 7 for further details.Ducts through the walls must be insulated and all jointstaped or sealed to prevent air or moisture entering thewall cavity.Some installations may not require any return air duct.A metallic return air grille is required with installationsnot requiring a return air duct. The spacing betweenlouvers on the grille shall not be larger than 5/8 inch.NOTE: If no return air duct is used, applicableinstallation codes may limit this cabinet toinstallation only in a single story structure.Any grille that meets with 5/8 inch louver criteria maybe used. It is recommended that Bard Return Air GrilleKit RG2 through RG5 or RFG2 through RFG5 beinstalled when no return duct is used. (RFG filter is notincluded; must order separately.) Contact distributor orfactory for ordering information. If using a return airfilter grille, filters must be of sufficient size to allow amaximum velocity of 400 fpm.FILTERSA 1-inch throwaway filter is supplied with each unit.The filter slides into position making it easy to service.This filter can be serviced from the outside by removingthe service door. A 1-inch washable filter and a 2-inchpleated filter are also available as optional accessories.The internal filter brackets are adjustable toaccommodate the 2-inch filter by bending down the twohorizontal tabs on each filter bracket.FRESH AIR INTAKEAll units are built with fresh air inlet slots punched inthe service panel.If the unit is equipped with a fresh air damper assembly,the assembly is shipped already attached to the unit.The damper blade is locked in the closed position. Toallow the damper to operate, the maximum andminimum blade position stops must be installed. SeeFigure 2.All capacity, efficiency and cost of operationinformation as required for Department of Energy“Energyguide” Fact Sheets is based upon the fresh airBlank-off plate in place and is recommended formaximum energy efficiency.The blank-off plate is available upon request from thefactory and is installed in place of the fresh air dampershipped with each unit.