+---
+title: Active and Passive Chilled Beams
+category: Mechanical / Air Distribution
+toc_depth: 3
+description: >
+ When to use: Specification, selection, installation, and commissioning of active (ACB)
+ and passive (PCB) chilled beam terminal units for sensible cooling and supplemental
+ heating in commercial and institutional buildings (offices, higher education,
+ non-critical healthcare, hotels, laboratories) served by chilled water and a dedicated
+ outdoor air system; covers ceiling-recessed, ceiling-exposed, and multi-service
+ configurations, condensation protection, and controls integration.
+ Not intended for: radiant ceiling/floor panels ([[sync/radiant-heating-and-cooling-panels]]);
+ fan-coil units ([[sync/fan-coil-units]]); single-duct VAV terminals
+ ([[sync/variable-air-volume-terminals]]); the DOAS air-handling unit and primary-air
+ ductwork itself ([[sync/dedicated-outdoor-air-systems]]); hydronic distribution piping
+ and expansion loops ([[sync/expansion-fittings-and-loops]]); water-hammer control on
+ branch connections ([[sync/water-hammer-arrestors]]); temporary construction HVAC
+ ([[sync/temporary-facilities-and-controls]]); and overall-system O&M and closeout
+ documentation ([[sync/operation-and-maintenance-data]], [[sync/closeout-procedures]]).
+---
+
+# Scope {toc}
+
+## 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. {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. {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. {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. {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. {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. {note}
+
+## The following terminal types are excluded because they operate on a different principle or are governed by a dedicated standard. {note}
+
+### Radiant ceiling and floor panels exchange sensible heat by radiation without induction and are covered by [[sync/radiant-heating-and-cooling-panels]]. {note}
+
+### Fan-coil units use a motor-driven indoor fan and operate independently of a primary-air system; they are covered by [[sync/fan-coil-units]]. {note}
+
+### Single-duct variable air volume terminals without a chilled-water coil are covered by [[sync/variable-air-volume-terminals]]. {note}
+
+### The DOAS air-handling unit, its dehumidification capacity, and the primary-air ductwork that delivers air to the beams are covered by [[sync/dedicated-outdoor-air-systems]]. {note}
+
+### Hydronic distribution mains, branch piping, and expansion provisions serving the chilled-water circuits are covered by [[sync/expansion-fittings-and-loops]]; water-hammer control on branch connections is covered by [[sync/water-hammer-arrestors]]. {note}
+
+# Referenced Standards {toc}
+
+## Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+## 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. {note}
+
+## Passive 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 |
+
+# Submittals {toc}
+
+## Action submittals establish that the proposed beams meet the performance, acoustic, and dimensional requirements before fabrication. {note}
+
+### The 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.
+
+```datasheet
+label: Action Submittals
+type: checkbox
+options:
+ - 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
+default:
+ - Product data (each beam type)
+ - Shop drawings with connection locations
+ - AHRI-certified / ASHRAE 200 performance ratings
+ - Certified acoustic (NC) data
+ - Condensation-control sequence of operations
+```
+
+## Closeout submittals document the installed and commissioned condition for the operator. {note}
+
+### The Contractor shall submit the following closeout submittals:
+
+- Operation and maintenance data per [[sync/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.
+
+```datasheet
+label: Closeout Submittals
+type: checkbox
+options:
+ - Operation and maintenance data
+ - Field commissioning records (airflow + water flow)
+ - Dew-point sensor calibration certificates
+ - Condensation-cutout functional test reports
+ - Hydronic balancing report
+default:
+ - Operation and maintenance data
+ - Field commissioning records (airflow + water flow)
+ - Dew-point sensor calibration certificates
+ - Condensation-cutout functional test reports
+ - Hydronic balancing report
+```
+
+# Quality Assurance {toc}
+
+## Active chilled beams shall be certified under the AHRI 1240 (I-P) / 1241 (SI) rating program.
+
+## Performance 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.
+
+## Passive chilled beams, which have no AHRI certification program, shall be supported by manufacturer test data developed per ANSI/ASHRAE Standard 200.
+
+## Acoustic ratings shall be reported as NC at the design primary-air static pressure, not at an arbitrary reference condition.
+
+## Uncertified manufacturer performance data has historically been optimistic; requiring certified ratings protects the owner from beams that underperform at the design chilled-water temperature. {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. {note}
+
+## The system designer should follow the ASHRAE/REHVA Active and Passive Beam Application Design Guide for sizing, induction-ratio selection, and dew-point control.
+
+# Environmental and Service Conditions {toc}
+
+## 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. {note}
+
+## The chilled-water supply temperature shall remain above the room dew point at all operating conditions.
+
+## The 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.
+
+## The chilled-water supply temperature shall be selected at least 2-3°F (1-2°C) above the design room dew point.
+
+## 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. {note}
+
+## The space dew point at design conditions shall be established by the Engineer of Record.
+
+## 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. {note}
+
+### Design chilled-water supply temperature
+
+```datasheet
+label: Chilled-Water Supply Temperature
+type: range
+unit: °F
+min: 58
+max: 64
+step: 1
+default: 60
+```
+
+### Design chilled-water delta-T across the coil
+
+```datasheet
+label: Chilled-Water Delta-T
+type: range
+unit: °F
+min: 9
+max: 18
+step: 1
+default: 12
+```
+
+### Primary-air supply dew point from the DOAS
+
+```datasheet
+label: Primary-Air Dew Point (DOAS)
+type: range
+unit: °F
+min: 44
+max: 50
+step: 1
+default: 48
+```
+
+### Chilled-water working pressure rating
+
+```datasheet
+label: Chilled-Water Working Pressure
+type: radio
+unit: psi
+options:
+ - 150
+ - 300
+default: 150
+```
+
+# Beam Selection and Configuration {toc}
+
+## 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. {note}
+
+## The 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.
+
+## Active 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.
+
+## 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. {note}
+
+### Beam type
+
+```datasheet
+label: Beam Type
+type: radio
+options:
+ - Active chilled beam (ACB)
+ - Passive chilled beam (PCB)
+ - Room air induction unit (RAIU)
+default: Active chilled beam (ACB)
+```
+
+### Mounting configuration
+
+```datasheet
+label: Mounting Configuration
+type: radio
+options:
+ - Ceiling-recessed (lay-in tile grid)
+ - Ceiling-exposed / surface-mount
+ - Multi-service (integrated lighting/sprinkler/AV)
+default: Ceiling-recessed (lay-in tile grid)
+```
+
+### Ceiling module size for recessed beams
+
+```datasheet
+label: Ceiling Module
+type: select
+unit: in
+options:
+ - 24 × 24
+ - 24 × 48
+ - 24 × 72
+ - 24 × 96
+default: 24 × 48
+```
+
+### Coil rows
+
+```datasheet
+label: Coil Rows
+type: radio
+options:
+ - Single-row
+ - Two-row
+default: Single-row
+```
+
+### Design sensible cooling capacity per linear foot
+
+```datasheet
+label: Cooling Capacity per Linear Foot
+type: range
+unit: Btu/h·ft
+min: 150
+max: 700
+step: 25
+default: 400
+```
+
+### Primary airflow per linear foot (active beams)
+
+```datasheet
+label: Primary Airflow per Linear Foot
+type: range
+unit: cfm/ft
+min: 15
+max: 60
+step: 5
+default: 30
+```
+
+### Design induction ratio (active beams)
+
+```datasheet
+label: 'Induction Ratio (induced : primary)'
+type: select
+options:
+ - 3:1
+ - 4:1
+ - 5:1
+ - 6:1
+default: 4:1
+```
+
+### Chilled-water flow per beam section
+
+```datasheet
+label: Chilled-Water Flow per Section
+type: range
+unit: gpm
+min: 0.3
+max: 1.5
+step: 0.1
+default: 0.7
+```
+
+### Operating static pressure at the primary-air inlet (active beams)
+
+```datasheet
+label: Primary-Air Inlet Static Pressure
+type: range
+unit: in. w.g.
+min: 0.3
+max: 1.5
+step: 0.1
+default: 0.6
+```
+
+### Maximum noise criteria at design primary airflow
+
+```datasheet
+label: Maximum NC Rating
+type: range
+unit: NC
+min: 25
+max: 40
+step: 5
+default: 30
+```
+
+### Casing finish
+
+```datasheet
+label: Casing Finish
+type: select
+options:
+ - White powder-coat (standard)
+ - Custom RAL powder-coat
+ - Stainless steel
+ - Antimicrobial coating (healthcare)
+default: White powder-coat (standard)
+```
+
+# Heating Provisions {toc}
+
+## 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. {note}
+
+## Perimeter 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.
+
+### Heating method
+
+```datasheet
+label: Heating Method
+type: radio
+options:
+ - None (sensible cooling only)
+ - Integral hot-water coil
+ - Integral electric coil
+ - Primary-air heating only
+default: None (sensible cooling only)
+```
+
+### Design heating-water supply temperature
+
+```datasheet
+label: Heating-Water Supply Temperature
+type: range
+unit: °F
+min: 100
+max: 140
+step: 5
+default: 120
+```
+
+# Multi-Service Beams {toc}
+
+## 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. {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. {note}
+
+## Multi-service beams shall be identified in the project scope early enough that procurement lead time does not delay ceiling completion.
+
+## Integrated fire-suppression and electrical elements within a multi-service beam shall comply with their governing trade codes independently of the beam's mechanical rating.
+
+## Multi-service beams are longer and heavier than standard beams and shall be coordinated with the structural ceiling support before fabrication.
+
+## Multi-service beam layout shall be coordinated with the reflected ceiling plan before fabrication.
+
+### Integrated services
+
+```datasheet
+label: Integrated Services
+type: checkbox
+options:
+ - Recessed lighting
+ - Sprinkler head(s)
+ - Cable tray / power
+ - Speakers / AV
+default: []
+```
+
+# Connections {toc}
+
+## Chilled-water connections to beams shall be made with braided stainless-steel flexible hose connectors.
+
+## Beams 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.
+
+## Each beam shall be provided with a circuit-setter (memory-stop) balancing valve so that flow can be set and verified independently of adjacent beams.
+
+## 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. {note}
+
+## An oversized chilled-water control valve hunts and an undersized valve starves the coil; correct valve sizing is critical to stable beam operation. {note}
+
+## The chilled-water control valve shall be sized for the coil design flow, not the branch main.
+
+## Primary-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.
+
+## Ductwork penetrations and any plenum use shall comply with NFPA 90A, including fire-stopping at ceiling penetrations.
+
+### Chilled-water valve type
+
+```datasheet
+label: Chilled-Water Control Valve
+type: radio
+options:
+ - Two-way modulating
+ - Two-way on/off
+ - Pressure-independent control valve
+default: Two-way modulating
+```
+
+### Flexible connector size
+
+```datasheet
+label: Flexible Connector Size
+type: radio
+unit: in
+options:
+ - 3/8
+ - 1/2
+default: 1/2
+```
+
+### Primary-air duct connection location
+
+### 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 [[drawing: beam connection schedule]]. {note}
+
+# Controls and Condensation Protection {toc}
+
+## 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. {note}
+
+## The condensation-control sequence shall make chilled-water flow impossible whenever the room dew point approaches the chilled-water supply temperature.
+
+## The 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.
+
+## Each 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.
+
+## The 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.
+
+## 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. {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. {note}
+
+## The latent capacity of the DOAS shall be verified against the design humid-day condition.
+
+### Dew-point sensing location
+
+```datasheet
+label: Dew-Point Sensing
+type: radio
+options:
+ - Integral to beam
+ - Central BAS / per-zone space sensor
+default: Central BAS / per-zone space sensor
+```
+
+### Controls integration protocol
+
+```datasheet
+label: Controls Integration
+type: radio
+options:
+ - BACnet
+ - Modbus
+ - Analog I/O
+default: BACnet
+```
+
+### Chilled-water supply temperature reset
+
+```datasheet
+label: Dew-Point-Based CW Reset
+type: radio
+options:
+ - Enabled
+ - Disabled
+default: Enabled
+```
+
+# Testing {toc}
+
+## Factory test data shall be developed per the test-chamber methods of ANSI/ASHRAE Standard 200, which underlie the AHRI 1240 / 1241 ratings.
+
+## Field commissioning verifies that each beam actually receives its design air and water, because the certified capacity is only realized at the design flows. {note}
+
+## Primary airflow at each active beam shall be measured by pitot traverse or capture hood and shall be within ±10% of the design value.
+
+## Chilled-water flow at each beam shall be verified at the circuit setter using an ultrasonic meter or the valve's flow-measurement feature.
+
+## Each dew-point sensor shall be calibration-checked at commissioning.
+
+## The condensation-cutout sequence shall be functionally tested by driving the measured dew point above the lockout setpoint and confirming the chilled-water valve closes.
+
+### Field test acceptance tolerance
+
+```datasheet
+label: Primary Airflow Field Tolerance
+type: range
+unit: '%'
+min: 5
+max: 15
+step: 5
+default: 10
+```
+
+# Installation {toc}
+
+## Beams 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.
+
+## A 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.
+
+## Beam 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.
+
+## Primary airflow to active beams shall satisfy the zone minimum ventilation rate of ANSI/ASHRAE Standard 62.1.
+
+## 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. {note}
+
+## Beam 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.
+
+## Beams 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.
+
+## Flexible chilled-water connectors shall be installed without kinks and with sufficient slack to accommodate thermal movement of the branch piping.
+
+### Beam mounting location and orientation
+
+### Beam locations, throw orientation, and integration with the ceiling grid are layout arrangements shown on the drawings [[drawing: reflected ceiling plan]]. {note}
+
+# Delivery, Storage, and Handling {toc}
+
+## Beams shall be delivered with coil connections capped and induction nozzles protected from construction debris.
+
+## Beams shall be stored indoors, level, and protected from moisture, dust, and physical damage until installation.
+
+## Multi-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.
+
+# Warranty {toc}
+
+## The manufacturer shall warrant the chilled beams against defects in materials and workmanship for the period specified below from the date of Substantial Completion.
+
+## Coil leakage attributable to a manufacturing defect shall be covered under the warranty, including the labor to access and replace the affected beam.
+
+### Warranty period
+
+```datasheet
+label: Warranty Period
+type: radio
+unit: years
+options:
+ - 1
+ - 2
+ - 5
+default: 2
+```
+
+# Spare Parts {toc}
+
+## The Contractor shall furnish spare dew-point sensors and flexible connectors of the installed types to the Owner at closeout.
+
+## Attic-stock quantities should reflect the lead time of multi-service and custom beams, where on-site spares avoid extended outages.
+
+### Spare parts quantity
+
+```datasheet
+label: Spare Parts (percent of installed quantity)
+type: range
+unit: '%'
+min: 0
+max: 10
+step: 1
+default: 2
+```