P l D ii Properly Designing A Boiler Exhaust System - Cleaver

Properly
P
l D
Designing
i i
A Boiler Exhaust System
Common Problems Of Improperly
Designed Boiler Exhaust Systems
Common Problems
Boiler Inefficiency
Flame Ignition Failure
Downtime
3
Common Problems
Excess draft in the stack
Insufficient draft in the stack
Factors
Improper breeching sizing
Improper stack sizing
Poorly designed ventilation system
4
Important Criteria In
Stack System Design
Boiler Categorization
Stack Types
Stack Sizing
UL Certification
C tifi ti
Materials Of
Construction
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Boiler Categorization
CATEGORY I
APPLIANCE
NEGAT
TIVE
Boilers are divided into four categories based on the
pressure and temperature produced in the exhaust stack
and the likelihood of condensate production in the vent
vent.
CATEGORY III
APPLIANCE
CONDENSING
POSITIV
VE
NON-CONDENSING
CATEGORY II
APPLIANCE
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CATEGORY IV
APPLIANCE
Boiler Categorization
Category I
A boiler
b il which
hi h operates with
i h a non-positive
ii
vent static pressure and with a vent gas
temperature that avoids excessive
condensate production in the vent.
(B V t Type
(B-Vent,
T
A)
Category II
A boiler
b il which
hi h operates with
i h a non-positive
ii
vent static pressure and with a vent gas
temperature that may cause excessive
condensate production in the vent.
(T
(Type
BH)
Category III
A boiler which operates
p
with a p
positive vent
pressure and with a vent gas temperature
that avoids excessive condensate
production in the vent.
((Type
yp BH))
Category IV
A boiler which operates
p
with a p
positive vent
pressure and with a vent gas temperature
that may cause excessive condensate
production in the vent.
((Type
yp BH))
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Boiler Categorization
N
Near-Condensing
C d
i
Boilers
B il
Condensing Boilers
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Stack Types
Type B Gas Vents
• Gas Appliance with Draft Hood
Liners
• Masonry Chimneys
Type BH Gas Vents
• Most Cat II, III and IV boilers
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Stack Sizing
Draft
calculation
based on
criteria
c
te a
such as:
Appliance category
Altitude
Power input
Flue gas velocity
Type of fuel
Flow restriction: tees, elbows,
wyes, dampers, reducers
Flue gas temperature
Seasons
(summer vs. winter)
Stack and breeching
diameter, height, length
A d more…
And
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Stack Sizing
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UL Certification
UL 103 (USA) / ULC959 (CAN)
Building Heating
Appliance Chimney
•
IIntended
t d d for
f use with
ith gas and
d liquid
li id residential
id ti l ttype and
db
building
ildi
heating appliances which vent flue gases at a temperature not
exceeding 1000ºF under continuous operating conditions with a
maximum rated positive pressure of 60 inches W.C., as specified in
the Chimney Selection Chart of the National Fire Protection
Association Standard No. 211
•
Can be installed in an unenclosed installation or enclosed in a
noncombustible chase
•
Also complied with a temperature test at 1700ºF for 10 minutes
•
1400ºF Chimney: same as above, but for flue gases at a
temperature not exceeding 1400ºF
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UL Certification
UL 1738 (USA) / ULC S-636 (CAN)
Special Gas Vents
•
IIntended
t d d to
t be
b connected
t d directly
di tl to
t the
th flue
fl outlet
tl t off the
th Category
C t
II, III and IV gas burning appliances, as defined by the National Flue
Gas Code, ANSI Z223.1/NFPA 54, where the maximum continuous
flue gas temperature produced does not exceed 550ºF with a
maximum rated positive pressure of 15 inches W.C.
•
Can be installed in an unenclosed or an enclosed installation made
of combustible materials
•
Also complied with a temperature test at 1700ºF for 10 minutes
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UL Certification
UL 1777 (USA) / ULC S-635 (CAN)
Chimney Liners
•
IIntended
t d d to
t be
b installed
i t ll d iin masonry chimneys
hi
used
d tto ventt gas or oilil
fuel fired residential type and building heating appliances where the
maximum continuous flue gas temperature produced does not
exceed 570ºF
15
UL Certification
UL 1978 (USA & CAN)
Grease Duct For Restaurant
Cooking Appliances
•
IIntended
t d d for
f use in
i installations
i t ll ti
ffor th
the removall off smoke
k and
d
grease laden vapors in commercial and industrial applications
•
They are appropriate for continuous operation at temperatures not
exceeding 500ºF
500 F
•
Were evaluated in accordance with the Standard for Removal of
Smoke and Grease-Laden Vapors from Commercial Cooking
Equipment, NFPA 96
•
Also complied with an abnormal temperature test at 2000ºF for 30
minutes
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UL Certification
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Materials Of Construction
Installation-Ready Exhaust Systems
Structural
•
•
•
•
Stainless steel ((304 / 316 / 301 / AL29 4C))
Aluminized steel
ABS / PVC / CPVC / POLYETHYLENE
Galvanized steel
Insulation
• Air
• Mineral fiber
• Ceramic fiber
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Materials Of Construction
Freestanding Stacks
Structural
•
•
•
•
Carbon steel
Cor-Ten steel
Stainless steel
Other materials per customer specifications
Insulation
• Per customer specifications
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Other Considerations
Installation-Ready Exhaust Systems
Draft control systems
Dampers
Barometric draft controls
Negative
N
ti pressure
in the building
Modulating draft systems
Air inlet
Draft inducer fans
Clearances for the boiler
Draft hoods
Masonry chimney
Maximum length of
breeching or stack
Other Considerations
Freestanding Stacks
Duct works and
breeching systems
Platforms and ladders
Concrete pad and
footing design
FAA aircraft
warning system
Seismic calculations
Wind loads
Special anchoring
Lightening protection
Special steel
structural design
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Other Considerations
Local codes and regulations
Special support requirements
Chemical and
thermal conditions
ASME and CWB
certified products
Corrosion effects
UL certified products
Special paint requirements
Needs for related products:
economizer, SCR products,
silencer, other
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Cleaver-Brooks Product Offering
Installation-Ready
Exhaust Systems
Freestanding Stacks
Special Gas Vents
Chimney Liners
Grease Duct Products
cleaverbrooks.com/exhaustsolutions
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References
•
CSA B149.1-10: Natural Gas & Propane Installation Code – Applies to the installation of
Natural Gas & Propane Appliances & Equipment- http://www.csa.ca/cm/ca/en/standards
•
NFPA http://www.nfpa.org/categoryList.asp?categoryID=124&URL=Codes%20&%20Standards
•
•
211: STANDARD FOR CHIMNEYS, FIREPLACES, VENTS, AND SOLID FUEL-BURNING
•
NFPA 54: NATIONAL FUEL GAS CODE
UL- http://www.ul.com/global/eng/pages/?noredirect
•
UL103: Factory built chimneys-
•
UL1738: Vent or chimney connector dampers for oil
oil-fired
fired appliances
•
UL1777: Chimney liners
•
ANSI Z21.86: Vented gas-fired space heating appliances- http://www.ansi.org/
•
ASME STS-1 – 2011: Steel Stacks- http://www.asme.org/kb/standards
•
ASHRAE- http://www.ashrae.org/standards-research--technology/standards--guidelines
•
Manufacturer’s
Manufacturer
s Operations and Maintenance Manuals
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Eric Gravel
Sales Manager
egravel@cleaverbrooks.com
(450) 625-6060
clea erbrooks com/e ha stsol tions
cleaverbrooks.com/exhaustsolutions
25
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