Chilled Beam Selection

There are many different designs of chilled beams on the market, which makes the selection and comparison between product types and manufacturers difficult. However, there are technical details that can be compared when making a chilled beam selection.

Active chilled beam

The cooling capacity of chilled beams is one of the major selection criteria. The technical data of different manufacturers are comparable only if the cooling capacity measurements are made to the same testing standard namely BS EN 15116: 2008 Ventilation for Buildings – Chilled beams – Testing and rating of active chilled beams and EN 14518: 2005 Ventilation for Buildings – Chilled beams – Testing and rating of passive chilled beams.

Data should also be presented with using same parameter values such as primary air flow rate and temperature difference between mean water and room. It is essential to ensure that the air discharged from chilled beams entering the occupied zone does not have high air velocities that will cause draught and discomfort.

There are four main steps that should be taken into account when selecting chilled beams:

Calculation of heat loads within the design space

• Selection of thermal environment level.
• Range of room temperatures in the summer.
• Range of room temperatures in the winter.
• Calculation of required cooling capacity
• Internal and external loads.
• Shading of facades.
• Cooling effect of primary ventilation.
• Calculation of required heating capacity.
• Calculation of design space heat losses and air leakage

Calculation of supply air volume required by the design space

• Selection of the indoor air quality level.
• Minimum fresh air requirement.
• Humidity conditions.

Positioning of chilled beams for optimum performance

• Design for system flexibility.
• Consultation with architect and building services consultant.
• Provision for potential space partitioning changes.
• Orientation.

Selection of suitable chilled beams

• Selection of chilled beam type.
• Active or passive chilled beam.
• Active beams parallel or 90° to the façade.
• Integrated lighting and other services or not.
• Selection of the inlet water temperature (cooling) to avoid the risk of condensation.
• Selecting a sufficient temperature differential between the room air and mean cooling water temperature.
• Design primary air conditions in summer and winter.
• Selection of flow and return water temperature differential.
• Cooling.
• Heating.
• Calculation of maximum water flow rate.
• Maintaining turbulent water flow conditions.
• Minimum water mass flow rates to maintain turbulent flow conditions.
• Noise level and system pressure loss calculation.

Does the selected ventilated, cooled beam meet all the design criteria?

If not -> go back and reselect chilled beam type.
If yes -> proceed.