Patterson-Kelley MACH-05 User Manual
Page 16

MACH® Series
Gas-Fired Boiler
Installation
Page 12
C750/900/1050 Sidewall Inlet and Vent
 
3.6.9 Intake Duct Materials and Sizes: 
Material: PVC, CPVC (Schedule 40), single wall 
galvanized steel, or other suitable materials. 
The intake duct must be sized for a maximum pressure 
drop of 0.22 inches W.C., for the SCFM as specified 
below. 
Boiler Size
Required SCFM
1050 245
900 210
750 175
450 105
300 70
The installation of a bird screen on the intake 
termination is recommended. 
3.6.10 Sealing the Intake Duct
Proper sealing of the intake ductwork is necessary to 
prevent infiltration of air from conditioned space. 
Joints in PVC or CPVC must be cemented. For 
galvanized duct, wrap each joint and seam with 
adhesive aluminum tape. 
3.6.11 Intake Duct Connection to Boiler
Connect the air supply duct to the collar on the back of 
the boiler. Fasten the duct to the collar with sheet 
metal screws at 90º angles. Seal the joint. 
3.6.12 Intake Duct Terminations 
 
The roof intake termination must be an 
unrestrictive type, as shown above. 
Roof
Round
90° Elbow
Sidewall
Round
Air Inlet 
(tee mounted 
horizontally) 
No rain cap -
Unrestricted
Sidewall
Air inlet 
(Down Elbow 
Mounted) 
Exhaust Vent 
(Sidewall 
Venting 
Requires Up 
Elbow Mounted) 
