1 Scope
NOTE This standard covers the specification, selection, factory certification, installation, and commissioning of active and passive chilled beam terminal units used for sensible cooling and supplemental heating. (1.1)
NOTE A chilled beam transfers sensible heat between room air and a finned chilled-water (or hot-water) coil; it carries no fan and no latent-handling capacity and is therefore always paired with a dedicated outdoor air system that conditions ventilation air and bears the entire latent load. (1.2)
NOTE The two beam families behave differently and are scoped together here because they share the same coil technology, the same condensation-risk physics, and the same chilled-water plant. (1.3)
NOTE An active chilled beam (ACB) receives primary air from a DOAS through induction nozzles; the high-velocity primary jet induces a much larger flow of room air across the coil, so the ACB both ventilates and supplements cooling. (1.3.1)
NOTE A passive chilled beam (PCB) has no primary-air connection and relies solely on natural convection: room air warmed near the ceiling falls across the cold coil and descends back into the space. Ventilation for a PCB-served zone is delivered by a separate air system. (1.3.2)
NOTE Room air induction units (RAIUs) - sill-mounted or floor-standing induction units that use chilled water without an overhead beam - share the same induction principle and the same AHRI rating program, and are addressed by this standard as a variant of the active beam. (1.3.3)
NOTE The following terminal types are excluded because they operate on a different principle or are governed by a dedicated standard. (1.4)
NOTE Fan-coil units use a motor-driven indoor fan and operate independently of a primary-air system; they are covered by
Fan Coil Units.
(1.4.2) NOTE The DOAS air-handling unit, its dehumidification capacity, and the primary-air ductwork that delivers air to the beams are covered by
Dedicated Outdoor Air Systems.
(1.4.4) NOTE Hydronic distribution mains, branch piping, and expansion provisions serving the chilled-water circuits are covered by
Expansion Fittings And Loops; water-hammer control on branch connections is covered by
Water Hammer Arrestors.
(1.4.5) 2 Referenced Standards
2.1Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
NOTE There is no AHRI certification program for passive chilled beams; performance data for passive beams is drawn from manufacturer testing per ANSI/ASHRAE Standard 200, not from a third-party certification program. (2.3)
2.4Passive chilled beam manufacturer performance data shall be derived from testing per ANSI/ASHRAE Standard 200.
| Standard |
Title |
| AHRI 1240 (I-P) / 1241 (SI) (2017, R2023) |
Performance Rating of Active Chilled Beams |
| ANSI/ASHRAE 200-2015 (R2019) |
Methods of Testing Chilled Beams |
| ASHRAE/REHVA (2015) |
Active and Passive Beam Application Design Guide |
| ANSI/ASHRAE 55-2023 |
Thermal Environmental Conditions for Human Occupancy |
| ANSI/ASHRAE 62.1-2022 |
Ventilation and Acceptable Indoor Air Quality |
| ANSI/ASHRAE/IES 90.1-2022 |
Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings |
| NFPA 90A-2024 |
Installation of Air-Conditioning and Ventilating Systems |
| SMACNA (3rd Edition) |
HVAC Duct Construction Standards - Metal and Flexible |
3 Submittals
NOTE Action submittals establish that the proposed beams meet the performance, acoustic, and dimensional requirements before fabrication. (3.1)
3.1.1The Contractor shall submit the following action submittals for review:
- Product data for each beam type, including coil rows, nozzle configuration, and finish.
- Shop drawings showing beam dimensions, mounting brackets, primary-air and chilled-water connection locations, and integrated service elements.
- AHRI-certified performance ratings (active beams) or ASHRAE 200 test data (passive beams) for the selected models at design operating conditions.
- Certified acoustic data stating NC rating at the design primary-air static pressure.
- Coil pressure-drop curves for chilled-water and heating-water circuits.
- A condensation-control sequence of operations and dew-point sensor schedule.
- Ceiling reflected-plan coordination drawings for recessed and multi-service beams.
☑ Product data (each beam type)
☑ Shop drawings with connection locations
☑ AHRI-certified / ASHRAE 200 performance ratings
☑ Certified acoustic (NC) data
☐ Coil pressure-drop curves
☑ Condensation-control sequence of operations
☐ Reflected ceiling coordination drawings
NOTE Closeout submittals document the installed and commissioned condition for the operator. (3.2)
3.2.1The Contractor shall submit the following closeout submittals:
- Operation and maintenance data per Operation And Maintenance Data.
- Field commissioning records including measured primary airflow and chilled-water flow per beam.
- Dew-point sensor calibration certificates.
- Condensation-cutout functional test reports.
- A balancing report listing the circuit-setter setting at each beam.
☑ Operation and maintenance data
☑ Field commissioning records (airflow + water flow)
☑ Dew-point sensor calibration certificates
☑ Condensation-cutout functional test reports
☑ Hydronic balancing report
4 Quality Assurance
4.1Active chilled beams shall be certified under the AHRI 1240 (I-P) / 1241 (SI) rating program.
4.2Performance ratings for active beams shall be the AHRI-certified values; manufacturer-published data that is not AHRI-certified shall be accepted only when supported by a third-party witnessed test report per ANSI/ASHRAE Standard 200.
4.3Passive chilled beams, which have no AHRI certification program, shall be supported by manufacturer test data developed per ANSI/ASHRAE Standard 200.
4.4Acoustic ratings shall be reported as NC at the design primary-air static pressure, not at an arbitrary reference condition.
NOTE Uncertified manufacturer performance data has historically been optimistic; requiring certified ratings protects the owner from beams that underperform at the design chilled-water temperature. (4.5)
NOTE The ASHRAE/REHVA Active and Passive Beam Application Design Guide is the authoritative engineering reference for chilled beam systems; it is not code-enforceable but represents industry consensus on sizing, induction-ratio selection, and dew-point control. (4.6)
4.7The system designer should follow the ASHRAE/REHVA Active and Passive Beam Application Design Guide for sizing, induction-ratio selection, and dew-point control.
5 Environmental and Service Conditions
NOTE Condensation on the coil is the most common and most damaging failure mode for chilled beams; the chilled-water supply temperature dropping below the room dew point is the primary cause. (5.1)
5.2The chilled-water supply temperature shall remain above the room dew point at all operating conditions.
5.3The DOAS shall dehumidify the primary air to a dew point below the design chilled-water supply temperature before any chilled-water flow is permitted to the beams.
5.4The chilled-water supply temperature shall be selected at least 2-3°F (1-2°C) above the design room dew point.
NOTE For a typical 72°F (22°C), 50% RH office space the design room dew point is approximately 55°F (13°C); actual values depend on the project climate and occupancy profile. (5.5)
5.6The space dew point at design conditions shall be established by the Engineer of Record.
NOTE A higher chilled-water supply temperature improves chiller efficiency and is a primary reason to select chilled beams, but it reduces capacity per foot; the design balances energy benefit against installed beam length. (5.7)
5.7.1Design chilled-water supply temperature
5.7.2Design chilled-water delta-T across the coil
5.7.3Primary-air supply dew point from the DOAS
5.7.4Chilled-water working pressure rating
6 Beam Selection and Configuration
NOTE Beam type selection follows the ventilation strategy: an active beam is selected where primary air can be ducted to each zone and the beam is to provide ventilation; a passive beam is selected where ventilation is delivered separately and only supplemental sensible cooling is needed. (6.1)
6.2The beam shall be selected so that its AHRI-certified (or ASHRAE 200) sensible capacity at the design chilled-water supply temperature meets or exceeds the zone peak sensible load.
6.3Active beams shall be sized by the ventilation requirement first; the induction effect provides the supplemental cooling, so primary airflow shall not be increased beyond the ventilation rate solely to gain cooling capacity.
NOTE Over-delivering primary air to chase cooling capacity raises nozzle velocity, generates noise, creates drafts, and wastes DOAS fan energy; this is one of the most common chilled-beam design errors. (6.4)
6.4.1Beam type
● Active chilled beam (ACB)
○ Passive chilled beam (PCB)
○ Room air induction unit (RAIU)
6.4.2Mounting configuration
● Ceiling-recessed (lay-in tile grid)
○ Ceiling-exposed / surface-mount
○ Multi-service (integrated lighting/sprinkler/AV)
6.4.3Ceiling module size for recessed beams
24 × 24
24 × 48
24 × 72
24 × 96
6.4.4Coil rows
150700
Default: 400 Btu/h·ft
6.4.7Design induction ratio (active beams)
6.4.8Chilled-water flow per beam section
6.4.9Operating static pressure at the primary-air inlet (active beams)
0.31.5
Default: 0.6 in. w.g.
6.4.10Maximum noise criteria at design primary airflow
6.4.11Casing finish
White powder-coat (standard)
Custom RAL powder-coat
Stainless steel
Antimicrobial coating (healthcare)
7 Heating Provisions
NOTE A passive beam cannot deliver heating, and an active beam without a heating coil relies entirely on warm primary air; in perimeter zones with significant glazing this is frequently insufficient and a heating coil or supplemental baseboard is required. (7.1)
7.2Perimeter zones in heating-dominated climates shall be provided with a beam heating coil or supplemental perimeter heat where the warm primary air alone cannot meet the design heating load.
7.2.1Heating method
● None (sensible cooling only)
○ Integral hot-water coil
○ Integral electric coil
○ Primary-air heating only
7.2.2Design heating-water supply temperature
8 Multi-Service Beams
NOTE A multi-service beam integrates lighting, sprinkler heads, cable tray, or speakers into a single linear unit, reducing ceiling clutter and the coordination trade work between disciplines. (8.1)
NOTE Multi-service beams are typically custom, long-lead items and are the fastest-growing North American configuration; early identification is essential so that procurement does not delay the ceiling. (8.2)
8.3Multi-service beams shall be identified in the project scope early enough that procurement lead time does not delay ceiling completion.
8.4Integrated fire-suppression and electrical elements within a multi-service beam shall comply with their governing trade codes independently of the beam's mechanical rating.
8.5Multi-service beams are longer and heavier than standard beams and shall be coordinated with the structural ceiling support before fabrication.
8.6Multi-service beam layout shall be coordinated with the reflected ceiling plan before fabrication.
8.6.1Integrated services
☐ Recessed lighting
☐ Sprinkler head(s)
☐ Cable tray / power
☐ Speakers / AV
9 Connections
9.1Chilled-water connections to beams shall be made with braided stainless-steel flexible hose connectors.
9.2Beams shall be connected to the chilled-water branch with flexible connectors, not hard pipe, so that thermal expansion and vibration do not crack the coil headers.
9.3Each beam shall be provided with a circuit-setter (memory-stop) balancing valve so that flow can be set and verified independently of adjacent beams.
NOTE Active and passive beams have very different flow resistances; placing them on a common circuit without per-beam balancing valves causes uneven distribution and starved beams. (9.4)
NOTE An oversized chilled-water control valve hunts and an undersized valve starves the coil; correct valve sizing is critical to stable beam operation. (9.5)
9.6The chilled-water control valve shall be sized for the coil design flow, not the branch main.
9.7Primary-air ductwork to active beams shall be constructed and leakage-tested per the SMACNA HVAC Duct Construction Standards, because duct leakage directly reduces delivered primary airflow and therefore induction performance.
9.8Ductwork penetrations and any plenum use shall comply with NFPA 90A, including fire-stopping at ceiling penetrations.
9.8.1Chilled-water valve type
● Two-way modulating
○ Two-way on/off
○ Pressure-independent control valve
9.8.2Flexible connector size
9.8.3Primary-air duct connection location
NOTE The primary-air and chilled-water connection points for each beam are an arrangement that varies by ceiling layout and are coordinated on the drawings
beam connection schedule.
(9.8.4) 10 Controls and Condensation Protection
NOTE Condensation control is a safety-critical control function, not an optional efficiency feature; a latent failure in this sequence can allow condensation that damages ceilings and furnishings. (10.1)
10.2The condensation-control sequence shall make chilled-water flow impossible whenever the room dew point approaches the chilled-water supply temperature.
10.3The sequence of operations shall require the DOAS to be in operation and delivering dehumidified primary air before any chilled-water valve serving a beam is permitted to open.
10.4Each zone, or group of zones on a common chilled-water branch, shall be provided with a space dew-point sensor that locks out the chilled-water valve when the measured dew point rises toward the chilled-water supply temperature.
10.5The control system shall provide a dew-point-based chilled-water supply temperature reset so that the plant runs as warm as the humidity allows, maximizing chiller efficiency without risking condensation.
NOTE Without a dew-point-based reset the system either runs the chilled water too cold (risking condensation) or too warm (sacrificing capacity); active reset is what makes the energy benefit of chilled beams real. (10.6)
NOTE On a hot, humid day an undersized DOAS or a chilled-water temperature that creeps upward can let the room dew point exceed the coil temperature — the exact failure scenario the condensation lockout sequence is designed to catch. (10.7)
10.8The latent capacity of the DOAS shall be verified against the design humid-day condition.
10.8.1Dew-point sensing location
○ Integral to beam
● Central BAS / per-zone space sensor
10.8.2Controls integration protocol
● BACnet
○ Modbus
○ Analog I/O
10.8.3Chilled-water supply temperature reset
11 Testing
11.1Factory test data shall be developed per the test-chamber methods of ANSI/ASHRAE Standard 200, which underlie the AHRI 1240 / 1241 ratings.
NOTE Field commissioning verifies that each beam actually receives its design air and water, because the certified capacity is only realized at the design flows. (11.2)
11.3Primary airflow at each active beam shall be measured by pitot traverse or capture hood and shall be within ±10% of the design value.
11.4Chilled-water flow at each beam shall be verified at the circuit setter using an ultrasonic meter or the valve's flow-measurement feature.
11.5Each dew-point sensor shall be calibration-checked at commissioning.
11.6The condensation-cutout sequence shall be functionally tested by driving the measured dew point above the lockout setpoint and confirming the chilled-water valve closes.
11.6.1Field test acceptance tolerance
12 Installation
12.1Beams shall be installed level and supported independently of the ceiling grid in accordance with the manufacturer's mounting details and the structural support shown on the drawings.
12.2A minimum ceiling-plenum clearance of 12 in. (305 mm) above the beam shall be maintained for the primary-air duct connection and for maintenance access.
12.3Beam placement, throw direction, and spacing shall be coordinated to satisfy the comfort criteria of ANSI/ASHRAE Standard 55, avoiding drafts and cold-ceiling radiant asymmetry.
12.4Primary airflow to active beams shall satisfy the zone minimum ventilation rate of ANSI/ASHRAE Standard 62.1.
NOTE In most designs the beam primary air is the sole outdoor-air delivery to the zone; supplemental ventilation pathways, if any, are additive to the DOAS supply calculation. (12.5)
12.6Beam placement shall account for the primary-air supply ductwork routing within the available plenum, and plenum geometry for multi-service beams shall be verified before rough-in.
12.7Beams sized at peak full-occupancy load without applying an occupancy and plug-load diversity factor can over-cool partially occupied spaces; design assumptions should be confirmed against the owner's actual occupancy patterns.
12.8Flexible chilled-water connectors shall be installed without kinks and with sufficient slack to accommodate thermal movement of the branch piping.
12.8.1Beam mounting location and orientation
NOTE Beam locations, throw orientation, and integration with the ceiling grid are layout arrangements shown on the drawings
reflected ceiling plan.
(12.8.2) 13 Delivery, Storage, and Handling
13.1Beams shall be delivered with coil connections capped and induction nozzles protected from construction debris.
13.2Beams shall be stored indoors, level, and protected from moisture, dust, and physical damage until installation.
13.3Multi-service and custom beams shall be inspected for finish and dimensional conformance on delivery, given their long lead time and lack of a quick replacement path.
14 Warranty
14.1The manufacturer shall warrant the chilled beams against defects in materials and workmanship for the period specified below from the date of Substantial Completion.
14.2Coil leakage attributable to a manufacturing defect shall be covered under the warranty, including the labor to access and replace the affected beam.
14.2.1Warranty period
15 Spare Parts
15.1The Contractor shall furnish spare dew-point sensors and flexible connectors of the installed types to the Owner at closeout.
15.2Attic-stock quantities should reflect the lead time of multi-service and custom beams, where on-site spares avoid extended outages.
15.2.1Spare parts quantity