General - Johnson Controls YORK YMSFXH018BAAK Series Installation Manual

The first 36 inches of supply air plenum and ductwork must be constructed of
sheet metal as required by NFPA 90B. The supply air plenum or duct must
have a solid sheet metal bottom directly under the unit with no openings,
registers or flexible air ducts located in it. If flexible supply air ducts are used
they may be located only in the vertical walls of rectangular plenum, a
minimum of 6 inches from the solid bottom. Metal plenum of duct may be
connected to the combustible floor base, if not, it must be connected to the
unit supply duct exposed to the supply air opening from the downflow unit.
Exposing combustible (non-metal) material to the supply opening of a down-
flow unit can cause a fire resulting in property damage, personal injury or
death.
Exception warning to downflow:
Installations on concrete floor slab with supply air plenum and ductwork
completely encased must be not less than 2 inches of concrete (See NFPA
90A).

2.0 GENERAL

The unit can be positioned for bottom return air in the upflow position, left and right
return in the horizontal position, top return in downflow position.
This Air Handler provides the flexibility for installation in any upflow or downflow
horizontal application. The direct drive motors provides a selection of air volume to
match any application. 3-Speed motors provide selections of air flow to meet desired
applications.
Top and side power and control wiring, accessible screw terminals for control wiring
all combine to make the installation easy, and minimize installation cost. Please
contact your local distributor. See fig.1.
WARNING
5