Heat Controller HDG36 User Manual

HDG Series Air Handler 

INSTALLATION INSTRUCTIONS

 

Heat Controller, Inc.

5

Do not install this unit in manufactured (mobile) homes. Improper installation is more likely in 

manufactured housing due to ductwork material, size, location and arrangement. Installations in 

manufactured housing can cause fire resulting in property damage, personal injury or death.
EXCEPTION: Manufactured housing installations are approved only with documentation by a 

recognized inspection authority that verifies that the installation has been made in compliance 

with the instructions and all warnings have been observed.

Duct leaks can create an unbalanced system and draw pollutants such as direct, dust, fumes 

and odors into the home causing property damage. Fumes and odors from toxic, volatile or 

flammable chemicals, as well as automobile exhaust and carbon monoxide (CO), can be drawn 

into the living space through leaking ducts and unbalanced duct systems causing personal injury 

or death (see Figure 1).
• If air-moving equipment or ductwork is located in garages or off-garage storage areas, all joints, 

seams, and openings in the equipment and duct must be sealed to limit the migration of toxic 

fumes and odors including carbon monoxide from migrating into the living space.
• If air-moving equipment or ductwork is located in spaces containing fuel burning appliances 

such as water heaters or boilers, all joints, seams and openings in the equipment and duct 

must be sealed to prevent depressurization of the space and possible migration of combustion 

byproducts including carbon monoxide into the living space.

When used in cooling applications, excessive sweating may occur when unit is installed in an 

unconditioned space. This can result in property damage.

In compliance with recognized codes, it is recommended that an auxiliary drain pan be installed 

under all evaporator coils or units containing evaporator coils that are located in any area of a 

structure where damage to the building or building contents may occur as a result of an overflow 

of the coil drain pan or a stoppage in the primary condensate drain piping.

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 downflow 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).