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.
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.
FREQUENTLY ASKED QUESTIONS
The testing standard for chilled beam cooling capacity ensures that manufacturers’ technical data is comparable. The BS EN 15116:2008 standard for active chilled beams and EN 14518:2005 standard for passive chilled beams provide a common framework for measuring and rating cooling capacity. This allows designers and engineers to accurately compare products from different manufacturers and select the most suitable chilled beam for their project.
To determine the required cooling capacity for a specific space, you need to calculate the total heat gain, which includes internal heat gains (e.g., people, equipment, lighting) and external heat gains (e.g., solar radiation, transmission through walls and windows). You can use tools like heat gain calculations, thermal modeling, or building information modeling (BIM) to estimate the required cooling capacity. It’s essential to consider factors like occupancy, equipment density, and climate when selecting a chilled beam with the appropriate cooling capacity.
In addition to cooling capacity, other important technical details to consider when comparing chilled beam products include pressure drop, airflow rates, sound levels, and water flow rates. These factors can impact the overall performance, energy efficiency, and acoustic comfort of the chilled beam system. It’s essential to review the product specifications and technical data sheets to ensure the selected chilled beam meets the project’s requirements.
Chilled beams can be used in spaces with high humidity or moisture, but it’s crucial to select products designed for such applications. Look for chilled beams with features like condensate management systems, corrosion-resistant materials, and drainage provisions to ensure reliable operation and minimize the risk of water damage. Additionally, consider the dew point temperature and ensure the chilled beam is designed to operate within the expected humidity range.
Proper installation and commissioning of chilled beams are critical to ensure optimal performance, energy efficiency, and indoor air quality. It’s essential to follow the manufacturer’s installation guidelines, ensure correct piping and electrical connections, and perform thorough commissioning tests to verify the system’s performance. Additionally, consider hiring experienced installers and commissioning agents who have worked with chilled beam systems previously.
Common mistakes to avoid when selecting and designing chilled beam systems include oversizing or undersizing the system, neglecting to consider the specific application and space requirements, and failing to account for factors like pressure drop and airflow rates. It’s also essential to avoid selecting products based solely on initial cost, as this can lead to higher operating costs and reduced system performance over time. Instead, consider the total cost of ownership, energy efficiency, and long-term maintenance requirements when selecting a chilled beam system.
