Installation Manual
16            Canadian Air Handler Installation and Operation 
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.  
            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 
•  CAH050E 
•  CAH050CE
360 square inches  
(0.23 square meters)  
Clearances to 
combustible 
material is 0 in. to 
plenum and duct for 
first 36 in. (914 mm) 
and throughout the 
remaining ductwork 
system.  










