control dampers
DESCRIPTION
Control Dampers - March 211 Illinois Chapter of ASHRAE Meeting.TRANSCRIPT
Air Control Considerations For Energy Conservation & BMS Integration
Presenter: James Livingston,
Ruskin Company
� Control Damper Basics
� Control Damper Leakage
� Control Damper Design For Energy
Conservation
� Fire/Smoke Damper Acutators For
Energy Conservation
We Will Discuss
What is a Control Damper?
One or more movable blades
Mounts in ducts or openings
Regulates the flow of air
Control Damper Applications
� Air Handling Units (AHU)
� Mixing Boxes
� Fresh Air (FA)
� Return Air (RA)
� Backdraft Dampers (BD)
� Zone Mixing Dampers (ZMD)
Parts of a Control Damper
Frame
Blade
Linkage
Jamb Seals
Blade Seals
Galvanized
V-Groove Blades
Airfoil Blades
Aluminum
Frames
Damper Construction
V-Groove Blade Dampers
• Velocities less than 1500 FPM
• 3”- 4” Static Pressure
• Noise not a factor
Airfoil Blade Dampers
• Velocities above 2000 FPM
• Above 3”- 4” Static Pressure
• Noise is a concern
• Lowest Pressure Drop Required
How Are Fire, Fire/Smoke and Smoke Dampers Different?
� Maintains fire or
smoke walls
� Fire dampers - steel
construction
� Often have sleeves
� Usually not controlling
air
� That is changing!
Damper Leakage – What is it?
Per AMCA Publication 502, Damper
Application Manual for Heating,
Ventilating and Air Conditioning:
“The Air Leakage, or Sealing
Performance, of a closed damper is
the airflow leakage rate through the
damper for a given pressure
differential across the damper.”
Leakage
Why Are We Concerned?
� Code requirements
� Energy losses due to
escaping conditioned air through closed damper
� Maintaining pressure in system with closed
damper
Control Damper Leakage Classes
Smoke & Fire/Smoke Damper Leakage Classes
Damper Leakage Notes
� Leakage is a function of Pressure, not Airflow
� Generally expressed or plotted as:
� Cfm/ft² of damper face area at a certain pressure
and with a certain seating torque
� Metric: m³/second per m²
� Example for a 24” x 24” opposed blade
damper:
� 32 cfm/ft² @ 4” w.g. pressure with 5 inch-pounds/ft² torque applied holding damper closed
Calculating Leakage
� Most dampers have published leakage at 1”
w.g.
� Multiply the cfm leakage at 1” times the
square root of the desired pressure
� Example
� 10 cfm @ 1” w.g. = 20 cfm @ 4” w.g.
� Be sure the damper is rated for the higher pressure!
17
International codes have been adopted in International codes have been adopted in
All 50 states, D.C. & Puerto RicoAll 50 states, D.C. & Puerto Rico
One or more International Codes currently enforced statewide
www.iccsafe.org
International CodesInternational Codes
International CodesInternational CodesInternational codes mandate…
� Occupancy-based ventilation (IMC 403.3)
� VAV systems shall have controls to monitor and maintain O.A. flow based on 403 requirements, through the entire range of the system (IMC403.3.3)
� All dampers penetrating the building envelope shall be class 1 leakage rated, not to exceed 4cfm/sf @ 1”w.c. (IMC301.2, IBC1301 & IECC)
� Motorized dampers required on building envelope penetrations (IECC 502.4.4 & 503.2.4.4)
D.O.E. mandates ASHRAE 90.1 as a minimum for all
Federal buildings. (IECC 4 CFM Supersedes)
“The occupant load utilized for design of the
ventilation system shall not be less than the
number determined from the estimated maximum
occupant load rate indicated in Table 403.3”
International CodesInternational Codes
International Mechanical CodeInternational Mechanical Code
Regard
ing Ene
rgy
Conser
vation
International Mechanical CodeInternational Mechanical Code
Regard
ing Ene
rgy
Conser
vation
International Building CodeInternational Building Code
International Energy Conservation CodeInternational Energy Conservation Code
• Required in all states that have
adopted the IBC or IMC.
• Addresses OA & EA Damper
leakage
4 cfm/ft2@ 1” w.g.
• Economizers Required (503.3.1 &
503.4.1)
• Refers to 90.1 for climate zones
and as a standard for
applications not covered in the
code.
International Energy Conservation CodeInternational Energy Conservation Code
ASHRAE 90.1
6.4.3.3.3 Motorized dampers
required on OA & EA applications
6.5.1.1 Economizers required
Specifying Low Leakage Dampers
� AMCA 511 Certification
� Independent testing
� Verified catalogs
� Periodic Check Tests
27
Certified Ratings Program…
How do you know the product you specified is licensed by AMCA International?
There are basically four ways to determine if a product is participating in AMCA International’s Certified Ratings Program. They are:
� WWW.AMCA.org
� Manufacture
� Model #
� Manufacture’s Catalog (most are online)
� Certified Ratings Seal on the product (could be too late)
� Contact AMCA International
� Phone 847-394-0150
� Fax 847-253-0088
� Email [email protected]
AMCA International
AMCA 511 Damper Air Leakage
� At least two sizes tested
� 12” x 48”
� Max width x 36”
� Up to two more sizes can be tested, 36” max tall
� AMCA configs 5.4, 5.5 or 5.6
� Round dampers
� Min & Max sizes tested
� AMCA 500 Test Standard
Figure 5.5
Leakage &
Pressure
AMCA 511 Damper Air Leakage
Damper Leakage Chart
Damper Leakage Performance
Air Leakage Certification
Not the same!
Be sure it’s rated for Air Leakage, not just Air Performance!
Energy Saving Damper Construction
Blades
Jamb Seals
Blade Seals
Galvanized
V-Groove Blades
Airfoil Blades
Aluminum
Blades
Generally not Class 1
Class 1 and 1A available
Airfoil Blades
� Advantages
� Best Torsion Performance
� No Twist
� Best Closure Seal For
All Blade Lengths
� Class 1 & 1A available
� Blade Shape Matters
� Airfoil
� 60” Span @ 3.5 w.g.
� 3000 FPM
� 3-VEE
� 48’ Span @ 2.5 w.g.
� 1500 FPM
Airfoil vs. “V” Groove Maximums
24” x 24”
Airfoil
.07 w.g. @ 2000 FPM
3-VEE
.19 w.g. @ 2000 FPM
Almost 3 times the Pressure Drop!
Airfoil vs. “V” Groove Pressure Drop
Jamb Seals
� Between ends of
blades and jamb
frames
� Metallic or synthetic
material
� Compresses when
blades close
Blade Seals
� Blade Seals
� Mechanically Locked
� Inflatable
� Wiper Type
No Adhesive or Clip On Style
Maintenance
Insulated Dampers� Reduces thermal energy loss
� Different methods
� Double airfoil damper -
expensive
� Single airfoil foam injected
blades – less expensive
� Thermal break frames available
� Class 1 leakage
� Applications down to -100°F
41
Louver & Damper in One!
Combination Louvers� Drainable fixed louver & airfoil
control damper in same frame
� Class 1 leakage
� Meets IECC building envelope
leakage requirement!
� Available w/ most electric
actuators
� Less product cost than separate
louver, damper & sleeve
� Less installation cost
Damper Electric Actuators
Electric Actuator Types
� Actuators are available in three types:
1) Two Position Spring Return
2) Modulating
3) Power Open-Power Closed
� Can be controlled by BMS
� Most Damper applications call for
Two Position Spring Return or Modulating
Two Position
� Limit to limit operation – does not float
� Open/close applications
� Spring reverses direction when power fails
� Typically 120V or 24V voltage
� Power draw for common 175 in/lb model� 120V – 60 VA driving, 13 VA holding
� 24V – 40 VA driving, 8 VA holding
Modulating� Actuator moves too any point within
its rotation limits to control airflow
� Requires a control signal� 2-10 Vdc or 4-20 mA
� Signal can come from BMS based on:� Temperature
� Pressure
� Air pollutants and/or occupancy
� Power draw for common 175 in/lb model� 24V – 16 VA driving, 5 VA holding
Actuator Installation Options
Modulating Considerations
� Airflow not linear to blade position
Modulating Considerations
Linear flow damper characteristics
From AMCA Pub 502 Damper Application Manual
Modulating Fire/Smoke and Smoke Damper Actuators
� BMS signal controls
blade position in normal
condition
� Damper closes fully
during fire
� Damper opens fully to
relieve smoke
Modulating Smoke & F/S Dampers
� Eliminates balancing
dampers
� Less pressure drop
� Less cost
� Use smoke dampers for
return air on Air Handlers
� Maintain floor pressure in
multi floor systems
Modulating Smoke & F/S Dampers
Modulating Smoke & F/S Dampers
� Advantage over
manual balancing
dampers
� Modulating actuator goes full-open for
smoke purge
� Smoke system does not have to fight semi-
closed manual dampers
Built in potentiometer to Built in potentiometer to
20% to 100% balance 20% to 100% balance
positionposition
Allows the damper to be SET at Allows the damper to be SET at Allows the damper to be SET at Allows the damper to be SET at Allows the damper to be SET at Allows the damper to be SET at Allows the damper to be SET at Allows the damper to be SET at
any position for BALANCING any position for BALANCING any position for BALANCING any position for BALANCING any position for BALANCING any position for BALANCING any position for BALANCING any position for BALANCING
AIRFLOW under normal AIRFLOW under normal AIRFLOW under normal AIRFLOW under normal AIRFLOW under normal AIRFLOW under normal AIRFLOW under normal AIRFLOW under normal
operations, open or closed for operations, open or closed for operations, open or closed for operations, open or closed for operations, open or closed for operations, open or closed for operations, open or closed for operations, open or closed for
SMOKE CONTROL and closed as SMOKE CONTROL and closed as SMOKE CONTROL and closed as SMOKE CONTROL and closed as SMOKE CONTROL and closed as SMOKE CONTROL and closed as SMOKE CONTROL and closed as SMOKE CONTROL and closed as
required in the fire arearequired in the fire arearequired in the fire arearequired in the fire arearequired in the fire arearequired in the fire arearequired in the fire arearequired in the fire area
No Control No Control No Control No Control
Signal Signal Signal Signal
RequiredRequiredRequiredRequired
3-Position Smoke & F/S Dampers
Summary
� Current building codes require low leakage
dampers
� Damper construction greatly affects leakage
characteristics
� Modulating actuators can be controlled by
BMS to adjust airflow for temperature and
IAQ requirements
� Smoke and Fire/Smoke dampers are
available w/ modulating & 3-position
actuators
Questions?
Thank You!