York AVV25B Installation Manual

5292157-UIM-B-0317Johnson Controls Unitary Products 7Use flexible duct collars to minimize the transmission of vibration/noiseinto the conditioned space. If electric heat is used, non-flammablematerial must be used.All ducts should be suspended using flexible hangers and neverfastened directly to the structure.HORIZONTAL SUSPENSIONThese air handlers may be suspended in horizontal applications. It isrecommended to use angle steel support brackets with minimum 3/8”threaded rods, supporting the unit from the bottom. Attach the threadedrods at the locations shown in the Figure 7, leaving enough clearancebetween door and rod so that doors maybe easily removed for service.DUCT FLANGESThree duct flanges are provided to assist in positioning and attachingduct work to the air handler. These flanges are included in the unit partsbag. With the screws from the parts bag, install one of the duct flanges.Duct flanges have holes on both legs with one leg longer than the other.The longer leg can be used to mate against the air handler so thatdifferent thicknesses of duct board can be made flush with the outersurface of the air handler. Repeat the procedure for the other twoflanges. Refer to Figure 8. If the flanges are not used, they may bediscarded.UNIT CONNECTIONSThere are several ways to handle the supply and return air ductconnections. The location and sizing of the connections depends on thesituation and the method best suited to the installation. Upflow,horizontal or downflow applications may be used.The supply air duct should be properly sized by use of a transition tomatch unit opening. Refer to Table 1 for air handler unit inlet and outletdimensions.Duct work that is not designed to match the supply air opening cancause turbulence inside the plenum. This turbulence can change the airflow patterns across the electric heater limit switches. If the factorysuggested transition cannot be fabricated, it is recommended that ablock off plate (approximately 8" high and running the full width of theplenum) be attached to the supply opening. Refer to Figure 9 as avisual aid. The use of this block off plate will enable better air circulationacross the limit switches.CAUTIONThis unit is not designed for non-ducted (freeblow) applications. Donot operate without duct work attached to unit.Equipment should never be operated without filters.CAUTIONDO NOT lift air handler by the cabinet brace. The cabinet brace isheld in place by the coil channel. The cabinet brace could becomedisengaged from the cabinet causing the air handler to fall, potentiallycausing injury or damaging property. See Figures 2 or 3 for location ofcabinet braces.NOTICEWhen assembling the support structure, make sure to size to provideclearance for access door removal.Dimension in InchesAir Handler Cabinet Size X H17-1/2 Width-Short H 21 4117-1/2 Width-Long H 21 47-1/221 Width-Short H 21-1/2 51-1/221 Width-Long H 21-1/2 55-3/424-1/2 Width 21-1/2 55-1/2FIGURE 7: Horizontal Suspension!!SUSPENSION SUPPORT LOCATIONS FOR HORIZONTAL APPLICATIONSXH2” 1-1/2”MIN. 1-1/2” x 1-1/2”Angle Recommendedlength 26” minimumwith 2” clearanceon both sidesof Air HandlerMIN. 3/8”THREADED RODXH1-1/2”1-1/2”MIN. 1-1/2” x 1-1/2”Angle Recommendedlength 26” minimumwith 2” clearance onboth sides ofAir HandlerMIN. 3/8”THREADED RODA0331-001FIGURE 8: Duct AttachmentFIGURE 9: Duct Work TransitionCAUTIONUse 1/2” screws to connect duct work to unit. Longer screws willpierce the drain pan and cause leakage. If pilot holes are drilled, drillonly though field duct and unit bottom duct flange.A0445-001DUCT FLANGES(Shipped in bag with unit)A0332-001RECOMMENDEDTRANSITION SUGGESTED LOCATIONOF BLOCK OFF PLATE!