Control Dampers - March 211 Illinois Chapter of ASHRAE Meeting.

1. Air Control Considerations
For Energy Conservation &
BMS Integration
Presenter: James Livingston,
Ruskin Company

2. We Will Discuss
Control Damper Basics
Control Damper Leakage
Control Damper Design For Energy
Conservation
Fire/Smoke Damper Acutators For
Energy Conservation

3. What is a Control Damper?
One or more movable blades
Mounts in ducts or openings
Regulates the flow of air

4. Control Damper Applications
Air Handling Units (AHU)
Mixing Boxes
Fresh Air (FA)
Return Air (RA)
Backdraft Dampers (BD)
Zone Mixing Dampers (ZMD)

5. Parts of a Control Damper
Frame
Linkage
Blade
Jamb
Seals
Blade
Seals

6. Damper Construction
Galvanized Aluminum
Frames
V-Groove Blades
Airfoil Blades

7. V-Groove Blade Dampers
• Velocities less than 1500 FPM
• 3”- 4” Static Pressure
• Noise not a factor

8. Airfoil Blade Dampers
• Velocities above 2000 FPM
• Above 3”- 4” Static Pressure
• Noise is a concern
• Lowest Pressure Drop Required

9. 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!

10. 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.”

11. Leakage

12. Why Are We Concerned?
Code requirements
Energy losses due to
escaping conditioned
air through closed
damper
Maintaining pressure
in system with closed
damper

13. Control Damper Leakage Classes

14. Smoke & Fire/Smoke Damper
Leakage Classes

15. 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

16. 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
International codes have been adopted in
All 50 states, D.C. & Puerto Rico
One or more International Codes
currently enforced statewide
www.iccsafe.org
17

18. International Codes
International 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)

19. International Codes
“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”

20. International Mechanical Code

21. International Mechanical Code
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22. International Building Code
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23. International Energy Conservation Code

24. International 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.

25. ASHRAE 90.1
6.4.3.3.3 Motorized dampers
required on OA & EA applications
6.5.1.1 Economizers required

26. Specifying Low Leakage
Dampers
AMCA 511 Certification
Independent testing
Verified catalogs
Periodic Check Tests

27. AMCA International
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 crp@amca.org
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28. 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

29. AMCA 511 Damper Air Leakage
AMCA 500 Test Standard
Figure 5.5
Leakage &
Pressure

30. Damper Leakage Chart

31. Damper Leakage Performance

32. Air Leakage Certification
Not the same!
Be sure it’s rated for Air Leakage, not just Air Performance!

33. Energy Saving Damper
Construction
Blades
Jamb
Seals
Blade
Seals

34. Blades
Galvanized Aluminum
V-Groove Blades
Generally not Class 1
Airfoil Blades
Class 1 and 1A available

35. Airfoil Blades
Advantages
Best Torsion Performance
No Twist
Best Closure Seal For
All Blade Lengths
Class 1 & 1A available

36. Airfoil vs. “V” Groove Maximums
Blade Shape Matters
Airfoil
60” Span @ 3.5 w.g.
3000 FPM
3-VEE
48’ Span @ 2.5 w.g.
1500 FPM

37. Airfoil vs. “V” Groove Pressure
Drop
Airfoil
24” x 24”
.07 w.g. @ 2000 FPM
3-VEE
.19 w.g. @ 2000 FPM
Almost 3 times the Pressure Drop!

38. Jamb Seals
Between ends of
blades and jamb
frames
Metallic or synthetic
material
Compresses when
blades close

39. Blade Seals
Blade Seals
Mechanically Locked
Inflatable Maintenance
Wiper Type
No Adhesive or Clip On Style

40. 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. 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
Louver & Damper Less product cost than separate
in One!
louver, damper & sleeve
Less installation cost
41

42. Damper Electric Actuators

43. 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

44. 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

45. 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

46. Actuator Installation Options

47. Modulating Considerations
Airflow not linear to blade position

48. Modulating Considerations
Linear flow damper characteristics
From AMCA Pub 502 Damper Application Manual

49. 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

50. Modulating Smoke & F/S Dampers

51. 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

52. 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

53. 3-Position Smoke & F/S Dampers
No Control
Signal
Required
Built in potentiometer to
20% to 100% balance
position
Allows the damper to be SET at
any position for BALANCING
AIRFLOW under normal
operations, open or closed for
SMOKE CONTROL and closed as
required in the fire area

54. 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

55. Questions?

56. Thank You!