The document discusses active beam systems, including their origin, overview, function, construction, comparisons to other systems, air-side and water-side information, capacity, benefits, limitations, and applications. Active beams are a hydronic system that uses water to transport energy and induce room air through nozzles to provide heating or cooling. They can provide significant fan energy savings compared to all-air systems while maintaining thermal comfort. Proper design of the air-side and water-side is important to control humidity and achieve capacity.

1. Twa Panel Systems Inc. April 12, 2012
1201 – 4th St.
Nisku, Alberta, Canada P: +1 (780) 955-8757
T9E 7L3 F: +1 (780) 965-8757
www.twapanels.ca

2. Agenda
• Active Beam Origin • Air-side Information
• Active Beam Overview • Water-side Information
• How A.B.’s Function • Capacity
• Construction • Benefits & Limitations
• System comparisons • Applications

3. Active Beam Origin
• Origins in Europe
Radiant Chilled Passive Chilled
Panels Sails Beams
(1950’s) (1990’s) (1990’s)
Perimeter Modular Active
Induction Unit
(1950’s)
Chilled Beams
(2000’s)

4. Active Beam Overview
• High acceptance rate in Europe
• Historically high energy costs
• North American market increasing due largely to:
• Green initiatives
• Increasing energy costs
• Increased installed base (Familiarity & Successful projects)
• Lowering cost due to increasingly competitive market

5. Active Beam Overview
• Hydronic systems use water as the
energy transport medium
• Water has many times the thermal
capacitance as compared to air

6. Active Beam Overview
Modes of Heat Transfer
Conduction Convection Radiation

7. How A.B.’s Function
A – Duct connection
S/A (primary Air) from the AHU
B – Primary air (P/A) plenum
Static Pressure forms and drives
P/A through nozzles
C – Perforated grille
Room air (Secondary air) is
induced, through grille, into coil
D – Unit mounted coil
2 or 4 pipe coil, cools/heats
the secondary air
E – Mixed air
P/A and secondary air mix
F – Discharge air
Mixed discharge air exits the beam, Coanda is induced to throw the air horizontally

8. How A.B.’s Function

9. Construction Standard Beam
Dimensions:
Width: 1’, 2’
Length: 2’, 4’, 6’, 8’, 10’
Standard Coil
Lengths:
2’, 3’, 4’, 5’, 6’, 7’, 8’, 9’, 10’
Various Nozzle Types
• Induction Ratio
• Acoustics
Discharge Pattern:
1, 2, & 4 - way
Other:
• Frame for Drywall
• Exposed – Coanda Wings

10. System comparisons
Active Beams
• Low Energy Consumption
• Reasonable Acoustics
• Low maintenance costs (No moving parts)
• Cooling Capacity: ~100 – 394 W/m2 (32 – 125 Btuh/ft2)
Versus
Fan Coil Units (FCU)
• Medium/High Energy Consumption
• Reasonable/Loud Acoustics
• Adaptable Solution
• Potential for high maintenance costs
• Cooling Capabilities: ~100 – 200 W/m2 (32 – 64 Btuh/ft2)
Variable Air Volume (VAV) System
• Low Energy Consumption
• Quiet/Reasonable acoustics
• Most efficient all air system
• Cooling Capabilities: ~100 – 200 W/m2 (32 – 64 Btuh/ft2)
Variable Refrigerant Volume (VRV) System
• High Energy Consumption
• Reasonable Acoustics
• Potential for high installation/maintenance costs
• Cooling Capabilities: ~150 – 200 W/m2 (48 – 64 Btuh/ft2)

11. Air Side Information
(Primary Air - Overview)
• Meet all ventilation requirements
• Min. Vent. (O/A requirements)
• Remove 100% of the latent loads (Psychrometrics)
• Induce enough Rm./A to meet sensible loads
**Greatest of these factors sets the minimum air flow rate**
• Higher SAT may be used
• May use heat recovery strategies for increased energy savings
• Decreased AHU & Duct size
• Decrease in fan energy

12. Air Side Information
(Primary Air)
• Majority of energy is saved at the FAN
• Air-side Load Fraction (ALF)
– The smaller the air-side load fraction, the more energy can be saved by
using a chilled beam system
Office Classroom Lobby
O/A Requirement 0.15 0.5 1
(cfm/ft2)
Air Volume (All Air System) 1 1.5 2
(cfm/ft2)
Air-side Load Fraction 15% 33% 50%

13. Air Side Information
(Primary Air)

14. Air Side Information
(Psychrometrics)
Psychrometric review required to prevent condensation
Standard Procedure:
• Remove moisture from the P/A at AHU
• Dry P/A lowers the space dew point temperature
• To prevent condensate on the coil:
Space dew point temp. < EWT
Not all spaces are suitable for active beams:
• Suitability engineering check - % of Sensible from CFMLatent

15. Air Side Information
(Psychrometrics)
Option 1 Option 2
Primary air dew
48°F 51.5°F
point
Room air dew
55°F 57.8°F
point
Secondary
55°F 58°F
CWT
Dehumidificatio
0.002 lbs/lbDA 0.002 lbs/lbDA
n
RESET FOR ENERGY
SAVINGS!

16. Air Side Information
(Psychrometrics & Climate Regions)
Legend:
■ Easy , Application of active beam products is natural
■ Medium , Application of active beam products requires some additional design
to control building moisture
■ Difficult, Application of active products is more difficult and humidity must be
carefully considered

17. Air Side Information
(P/A Design Parameters)
Typical Design Conditions (Cooling):
S/A Space
TDry Bulb: 55 - 65 F TDry Bulb: 75 F
TWet Bulb: 53 - 57 F TWet Bulb: 64 F
TDew point: 52 F TDew point: 58 F
R.H.: 55%
ΔGr = 13.64 Gr/lb
Typical Design Conditions (Heating):
S/A Space
TDry Bulb: 65 F TDry Bulb: 70 F
R.H.: 50%
QL = 0.68*CFM*ΔGr Qs = 1.08*CFM*ΔT

18. Air Side Information
(Space Over Cooling)
• Maintain reasonable dew point control
• Meet 100% of latent load under Peak Design conditions
• Infiltration
• Maximum occupancy
• Other sources of moisture
• Limit over-cooling
• Keep air-side load fraction low
• Reset air temperature
• CHWS Shut-off control or EWT reset
• VAV for fluctuating occupancy

19. Air Side Information
(Air Velocities & Thermal Comfort)
ASHRAE Std. 55
• Occupied Zone
• ΔT and Air velocity determine
Thermal Comfort
• 80% Occupancy Satisfaction
• Radiant Affect
Active Beams
• Higher discharge air temp.
• Highest air velocities are at
the perimeter of the space

20. Air Side Information
(Air Velocities & Thermal Comfort)
Active Beam
Diffuser

21. Air Side Information
(Plenum Air Pressure Drop)
250
1.00”
230
0.93”
• Fan Static is higher
210 • Less penalty then high air flow
0.85”
Plenum Pressure [Pa]
190
• Can correlate pressure and air flow
0.77”
• Air volume is difficult to measure
170
0.69” K 60A
150
0.60” K 60C • Measuring pressure is easy and
130
0.52”
reliable
K 60D
110
0.44”
K 60B • Pressure is the common factor
90
0.36”
70
• Plenum and ducting should be
0.28” Primary air [l/s] sealed
50
0.20” 0 5 10 15 20 25 30 35 40
CFM 10 21 32 42 53 64 74 85

22. Air Side Information
(Acoustics)
45
40
2’x8’ – Larger Nozzles Chart reports
35 acoustic values
LwA [dB(A)]
without room
30 attenuation
effect
25
2’x8’ – Smaller Nozzles Active beams can
20
be very quiet!
15
0.4 0.6 0.8 1 1.2 1.4
Plenum Pressure [“w.c.]

23. Air Side Information
(Air Side Controls)
• CAV primary air flow is
typically simple with
Total capacity
orifice plate “Iris” type
dampers.
• Varying the plenum
pressure yields a non-linear
capacity response. Tight
control with variable
plenum pressure is typically
impractical.
Static pressure

24. Air Side Information
(Air Side Controls)
• Occupancy Valve may solve
the issue of over-cooling a
Total capacity
space with un-tempered
primary air.
• Plenum static pressure
range (0.3”-1.2” w.c. max)
• VAV modulation range is low
with active beams
Primar y air volume

25. Air Side Information
(Possible Dampers)
Iris Dampers –
(angled multi-leaf
blades)
Pressure independent –
butterfly type
Iris Dampers

26. Air Side Information
(Common Design Pitfalls)
• Two Air-side Design Concerns:
1) Psychrometrics (Cooling only)
2) Preliminary Design based on DOAS system

27. Water Side Information
(Overview)
• Coil responsible for majority of the sensible load
• Cooling & Heating
• Design requires:
• Water flow rate
• Circuit pressure drop
• Temperatures (EWT, LWT)
• Increase in pump size and pump energy
• Fan Energy vs. Pump Energy = Net energy savings

28. Water Side Information
(Water Design Parameters)
• Active Beam Cooling:
• EWT temperature, typically between 56 – 62 F
• Secondary CHWS loop required
• Psychrometrics – (Condensation control)
• Generally EWT = 1 – 2 F above SPACE dew point temp.
• Active Beam Heating:
• EWT temperature, typically between 100 – 120 F
• Secondary HWS loop required
• Minimum flow rate per circuit = 0.45 to 0.65 GPM
• Prevent laminar flow (more important for cooling)

29. Water Side Information
(Piping Design)
Water system pressure control
• Variable speed pump and
differential pressure sensor
• Reduces energy by lowering
pump loading
• Maintain constant pressure
• Can cause imbalances in the
system when not at full flow if
pressure independent flow
control valves are not used

30. Water Side Information
(Piping Design)
Direct return
• Length of pipe varies from supply
header to return header for each
unit
• Change in pressure drop from one
circuit to another, affects flow rates
• Use balancing valves or circuit
setters
• Can cause imbalances in the
system when not at full flow if
pressure independent flow control
valves are not used

31. Water Side Information
(Piping Design)
Reverse return
• First supplied, last returned
• Zone or array is self-balancing
• Number of balancing valves can
be reduced
• Additional pipe length required
• May require pressure
independent flow control valves at
mains for zone take off

32. Water Side Information
(Piping Design)
Parallel piping
• Used exclusively for chilled
beams
• Reduced pressure loss
• Lower flow rates to achieve ΔT
• Better temperature distribution
and response

33. Water Side Information
(Water Side Controls)
On/Off valve Turbulent flow
• Inexpensive
Secondar y Capacity
• Adequate control
• Flow remains turbulent
• Req’d for mix mode ventilation
• Small & large zones
Laminar
Proportional control valve flow
• Expensive
Water gpm
• Advanced control not required
• Flow becomes laminar (cooling) 0
0 50
0.22 100
0.44
• Potential for searching
Minimum flow rate per circuit
= 0.45 to 0.65 GPM

34. Water Side Information
(Common Design Pitfalls)
• Three water-side Design Concerns:
1) Use of Glycol as the operating fluid
• Especially in cooling
2) Not considering Pressure independent flow control valves
• Especially with large hydronic systems
• Modulating valves
• Variable frequency drive pumps
3) Valve & Entrapped air noise

35. Capacity Overview
Air Side:
• 100% Latent energy capacity, increase by:
• Increasing ΔGr between P/A & Rm/A
• Increasing air flow rate
• Minority of sensible capacity, increase by:
• Increasing ΔT between P/A & Rm/A
• Increasing air flow rate
Water Side:
• Majority of sensible capacity, increase by:
• Increasing ΔT between water & Rm/A
• Increasing water flow rate
Total Capacity = Air capacity + Water capacity

36. Capacity vs. Air Volume
40
A-DT 8
A-DT 10
35
B-DT 8
B-DT 10 • Increasing air flow rate and
C-DT 8
30
C-DT 10
D-DT 8
pressure:
D-DT 10
Air Volume [l/s]
• Significant Increase in Capacity
25
20 • Increasing GPM in turbulent
flow:
15
• Marginal Increase in Capacity
10
Secondary Capacity [W]
5
100 200 300 400 500 600 700 800
Typical sensible range is approx. 250 – 1500 BTUh/Ft

37. Capacity
(Performance Data)
• Applicable standards:
• EN 15116: Chilled Beams
• ASHRAE/AHRI - SPC 200
• When choosing a manufacturer, ensure they
test to an applicable standard!

38. Active Beam Benefits
• Significant Fan Energy savings
• lower overall S/A
• Increased air circulation with high thermal comfort
• Smaller AHU & Ductwork
• Lower floor-floor heights
• Good retrofit applications
• Significant reduction of riser space
• Low maintenance requirements
• Can be integrated with other energy saving systems
• Geothermal, ERV’s, Enthalpy wheel…etc
• Water side free cooling may be an option

39. Active Beam Benefits
• Spaces may be zoned
• Increased Comfort
• Reduced energy consumption
• Individual space temperature control (LEED Compliant)
• Quick response time
• Low to Reasonable Acoustics

40. Active Beam Limitations
• Potential for higher first cost
• Increase in pump energy
• Small Compared to Fan Energy Savings
• Limited air-side free cooling
• Limited VAV modulating range
• High importance for building humidity control in Cooling
• Dehumidification at the AHU is required
• May require a building envelope upgrade
• May require more sophisticated controls for humidity control
• May not be acceptable for all spaces, based on latent loads

41. Commercial
Applications Office spaces
Data centers
Shops/Stores
Sensible and Latent energy drive suitability
Institutional
Labs
Higher the sensible - the greater the energy savings Lecture Theatres*
Lower the latent - the easier it is to control the dew point temperature
of the space (Required due to no condensate pan) Government
Schools
Hospital**
Spaces with: Airports
• High sensible loads & low latent loads Clinics
• Ideal
Other
• High sensible loads & high latent loads
Child care facilities
• May be suitable with careful examination
*Occupancy may produce high
• Low sensible loads & high latent loads latent requirements
• Would not be recommended for use with chilled beams **Some areas such as surgical
suites do not allow room air to
be induce or circulated through
the HVAC equipment
Not a silver bullet, each space should be individually
reviewed to determine suitability

42. Applications
Open Office Area

43. Applications
Individual Office Area

44. Applications
Child Care Center

45. Applications
Coffee Shop

46. Questions