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 25
3.5 Flue Gas / Exhaust Venting
All vent installations shall be in accordance with NFPA 54/ANSI Z223.1, the National Fuel Gas Code, or
CAN/CSA-B149.1, the Natural Gas and Propane Installation Code, or applicable provisions of the local
building codes.
The vent material to be used for US and Canada is listed in the Table of Acceptable Materials for
Venting Systems located in
For interior clearance requirements, refer to
The vent shall extend at least three (3) feet above
the roof, or at least two (2) feet above the highest part of any structure within ten (10) feet of the vent.
Refer to
for an illustration of the flue termination. Additionally, the boiler vent shall terminate at
least three (3) feet above a forced air inlet located within ten (10) feet.
To prevent the possible re-circulation of flue gases, the vent designer must take into consideration such
things as prevailing winds, eddy zones, building configurations, etc.
Patterson-Kelley cannot be
responsible for the effects such adverse conditions may have on the operation of the
appliances
.
Vertical vents are allowed to be terminated with a variety of ends, including plain straight pipe, elbow, or
vent tee. Horizontal vents must be terminated with an elbow or vent tee. Similarly, a bird screen with
1”
x
1” openings is recommended for termination. Patterson-Kelley does not recommend using a vent rain
cap of any type.
Category II or IV Venting Installation
P-K STORM
™
boilers are dual certified as
Category II or IV
appliances, as defined in ANSI
Z21.13/CSA 4.9, latest edition and are not suit able for use with Type “B” Vents.
The vent material to
be used for US and Canada is listed in the Table of Acceptable Materials for Venting Systems located in
Vent installations shall be in accordance with NFPA 54/ANSI Z223.1, the National Fuel Gas Code, or
CAN/ CSA-B149.1, the Natural Gas and Propane Installation Code, or applicable provisions of the local
building codes.
N
OTE
:
For
Category II
installations, ensure the flue venting system is designed to maintain a
slightly negative exhaust pressure
between -
0.01” W.C. and -0.05” W.C.
N
OTE
:
For
Category IV
installations, ensure the flue venting system is designed to maintain a
slightly positive exhaust pressure which
MUST
BE
in the following ranges:
•
+0.01” W.C. and +0.22” W.C. (Direct Vent / Sealed Combustion)
•
+0.01” W.C. and +0.4” W.C. (Exhaust Only)
