Installation Guide

Hydronic Air Handler Installaon and Operaon Manual 19
Replacement of components due to water
quality damage is not covered by the warranty.
Unsuitable heating system water can cause
the formation of scale or sludge, which
affects system efficiency. It can also cause
corrosion and reduce life of the heat
exchanger.
Never use water that has been treated by a
reverse osmosis, deionized, or distilled
water to soften the water to fill the heating
system.
Louvers or return air grilles are field-supplied.
Local codes may limit application of systems
without a ducted return to single-story
buildings.
For a unit installed in a closet with a louvered
return opening, the minimum open area for
the louvers are:
Non-Ducted Return Closet Installation
Clearances to combustible material is 0 in.
from unit casing, and 0 in. to plenum and
duct for first 36 in. (914 mm) and throughout
the remaining ductwork system.
Clearance for servicing is 24 in. (610 mm) in
front of air handler.
FRONT
0 in.
SIDE
0 in.
BACK
0 in.
TOP
0 in.
BOTTOM
0 in.
SERVICING
24 in.
(610 mm)
Images are not to scale and are for illustration purposes
only. Images do not show a complete system with
plenums, duct pipes, etc.
Clearances to
combustible
material is 0 in. to
plenum and duct for
first 36 in. (914 mm)
and throughout the
remaining ductwork
system.
IMPORTANT
If the free area is not known, assume a 25%
free area for wood or a 75% free area for metal
louvers or grilles. Using the louver dimensions
and the 25% or 75% assumption, determine if
the louver open area meets the minimum open
area listed above.
If the return air plenum is used, the return air
grille should be immediately in front of the
opening in the plenum to allow for the free flow
of return air.
When not installed in front of the opening, there
must be adequate clearance around the air
handler to allow for the free flow of return air.
Air Handler Models Minimum Opening Area
AH083P/AH083CP
AH084P/AH084CP
320 square inches
(0.206 square meters)
AH125P/AH125CP
360 square inches
(0.23 square meters)
AH166P/AH166CP
AH206P/AH206CP
450 square inches
(0.29 square meters)