P-K Storm
TM
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: June 26, 2020
Released: June 26, 2020
©
Patterson-Kelley 2020
All Rights Reserved.
2691000273 P-K Storm ST2500-ST4000
Installation and Owners Manual Rev A.docx
Page 28
Sealed Combustion/Direct Vent Systems
These boilers are also certified for operation with a sealed combustion air and pressurized venting
system. Such a system employs a sealed combustion
air intake duct leading from outdoors and a sealed
exhaust vent terminating outdoors. Air flow through the system is maintained by the combustion air fan.
Allowable configurations of vent and air intake terminations are illustrated below.
The combined pressure drop of the air supply duct and exhaust vent must not exceed 0.44” W.C. This
pressure drop includes both the inlet and exhaust duct friction loss. The air inlet and the exhaust vent
must terminate on the same wall of the building and they must utilize fittings as shown below. This boiler
may be installed with sidewall vent using room air.
STORM
™
Category II/IV:
Through-the-roof (exhaust only)
STORM
™
Category II/IV:
Sidewall (exhaust only)
NOTE
The exhaust vent must be at least 3 feet above the air intake. The air intake and exhaust vent must
extend 6" to 12" from the exterior wall and be offset.
The inlet air duct loss should not exceed 0.22”
W.C
.
12” Minimum
36”
Minimum
Air Inlet
Exhaust
Vent