Chilled Beams – Why Are They Popular?

We need them for shelter, warmth or cooling, but buildings are required to be more than that these days. They need to look good, feel good and be good. By being good, we mean they need to be energy efficient. Ideally, designers or Building Services Design Consultants must plan for energy-efficient mechanical, electrical and plumbing (MEP) engineering design, and chilled beam technology is one of the options that hydraulics and plumbing design services offer for energy-efficient systems, with the close collusion of heating, ventilation and air conditioning (HVAC) mechanical engineering consultants or .

Growing in popularity in Australia, Scandinavia, central Europe, the US and the UK now, the first stirrings of chilled beam concepts, surprisingly enough, occurred in the early 1900s. In those days, under-sill inductions units were being developed. Then, during the 1960s, water from the River Thames was used by Shell Oil Headquarters in London to cool their building (using a secondary heat exchanger in the plant room). At the time, it was both efficient and just a little bit sci-fi. The significance of this system lies in the nature of building services energy consumption.

It is widely accepted that HVAC systems are responsible for almost half (49%) of all building services consumption. Cooling and humidification account for 3% of the total. A component of MEP systems that can reduce that percentage is always welcome. So, what’s so special about chilled beams? Just what are they?

Chilled beam systems are a specific type of air conditioning system that can both heat or cool large buildings. Funnily enough, chilled beam units appear similar to fluorescent lighting fixtures and are not necessarily always chilled. Essentially, chilled beams cool spaces using water rather than air. Copper pipes carry chilled or heated water and are passed through a ‘beam’ (a heat exchanger or radiator) which is hung a short distance from the room’s ceiling. A coil of aluminum fins on copper tubing inside a metal casing is what makes up the beam. A chilled water system cools water to between 55°F and 65°F. The beam thus cools the air around it, and the air becomes dense and moves downward. Warm air moves up from below to replace it, is cooled and then circulated back down, causing a constant flow of convection and cooling of the air in the room. 

Chilled beam systems typically use three main components: air handling units (AHUs), chillers and pumps. If the system is required to provide heating, a boiler is used. These units form a ceiling-mounted HVAC system that ultimately saves energy, increases interior comfort and happens to be a quiet operator.

There are two main kinds of chilled beams – active or passive. Active chilled beams connect to a system of ducts served by a central AHU (air handling unit). This system delivers fresh air through induction nozzles. The nozzles use a heat exchanger coil to induce secondary room air. Supply air is mixed with chilled air through the ventilation nozzles. Heating in active chilled beams works the same way, delivering warm air into the living space. Heating and cooling capacity is increased with this forced circulation. Using active chilled beams results in the need for reduced energy to operate fans, due to low pressure and the reduced amount of primary air that is circulated. 

Passive chilled beams circulate air through natural convection means, without using a fan. Exterior air is supplied through a separate diffuser or grille into the space. Water passing through it chills the beam and the air around it is cooled. As the surrounding air cools, it becomes denser and moves down in the room space. Warm air, which rises, then replaces the cool air. A chilled water temperature of 14-16˚C is maintained by chillers to flow through the system. The return temperature will be a few degrees warmer. The chiller works more efficiently because of the higher chilled water temperatures in chilled beam systems and lower temperature lift. 

A third type of chilled beam that has made a recent entry into the industry is a multiservice chilled beam, or MSCB. These are specifically designed for each project and provide heating, cooling, ventilation, lighting and sound, fire and cable pathway services. They are typically preferred in commercial buildings in Europe. 

All chilled beam systems reduce energy. The AHUs can be installed with energy-recovering devices so that energy can be recovered from the exhaust air and transferred to the supply air. Due to the higher chilled temperatures, free-cooling can be used for longer, where exterior low air temperatures can be used to chill the water. Both chilled water and hot water can, at low temperatures, be produced by air and ground source heat pumps. These heat pumps use less energy than boilers and chillers.

Saving Energy 

So, what kind of savings in energy result from using chilled beams?

The potential to save energy using chilled beams may range from 20% to 50%, depending on the weather and type of building. Water is known to transfer more energy than air. The use of water in chilled beam systems result in less energy usage. Also, since heating and cooling is delivered directly to the relevant space, chilled beams help facilities reduce the energy required for ventilation fans, saving money in the process. Overall heating and cooling costs are reduced because chilled beam systems transfer outside air to interior spaces where it is needed, rather than bring it into the entire facility and then condition it.

Benefits of Chilled Beam Systems

Chilled beam systems offer other potential advantages besides energy savings, including: 

• No moving parts result in quieter operation
• Not requiring mechanical rooms or large ducts results in an increase in available space
• Buildings with limited space to accommodate conventional conditioning systems can be retrofitted
• Maintenance needs are reduced, since there are no filters to maintain and beams stay dirt-free
• Widely applicable for commercial buildings
• Significant thermal efficiency
• Requires less ceiling space and height than traditional systems, thus facilitating shorter buildings with the same floor space for tenants.

Further benefits may be environmental, in that recyclable materials, such as steel, aluminium and copper, can be used to manufacture chilled beams. Potential resale value is increased and the procedure for decommissioning is easier, as scrap metal merchants prefer the materials free of refrigerants and oils. Also, chilled beams contribute to long-term sustainability in both new and renovated buildings.

Typically, a conventional cooling or heating system uses forced air. A forced air system is less efficient and more expensive due to the requirement of large ducts in taller buildings. A typical chilled beam system requires less outside air to operate than a forced air system. It only needs one air change every hour and uses air from the outside air to pressurise the space. Using a forced air system, eight to ten air changes of fresh air are needed.

Also, chilled beam systems can be prefabricated off site and then installed on site, reportedly saving up to 75% in labour costs.

The diverse benefits of chilled beam systems, including long-term costs, make these systems a preferred choice for hydraulics and plumbing design services in a building’s MEP engineering design and also Building Services Coordination. With experienced and technically certified HVAC mechanical engineering consultants on board, the trend of chilled beam systems seems to be headed in the right direction for sustainable construction.

Key Points of MEP Systems & Coordination for Sports Entertainment Venue

As long ago as 776 BC, the Greeks are believed to have participated in the first Olympics to honour Zeus in Olympia, a sanctuary site for Greek deities. The stadium of ancient days has progressed in leaps and bounds and the deities have changed, but the passions incited and contained in sporting stadia still remain. Stadia design today takes far more into consideration than contestants’ comfort and the impact of raucous spectators. Sports venues today strive to integrate sustainability, perfect lighting, ventilation and plumbing in their design. It is the coordination of MEP (M&E) systems and other disciplines that ultimately ensures a stable and comfortable sporting venue for the great celebration of sport and spectator facilities and hospitality arrangements, as well as a myriad additional uses for the venues, such as concerts and conferences. MEP coordination is critical for the success of sporting venues on various levels, and the use of Building Information Modelling (BIM) technology has been crucial for its success.

Sports venues play a special role in enhancing life as we know it. Therefore, MEP engineering designs for sporting venues must be developed and executed in a significantly different manner from other structures. We look at the key points of MEP systems and MEP coordination where these differences matter most. Lighting that is reliable, purposeful and aesthetically comfortable is a major consideration. Since sporting venues must cater to varied occupancy, open areas (including spaces with retractable roofs) and unusually shaped spaces (circular, oval, etc.), these venues experience near-constant fluctuation of temperature and illumination. Air flow must be adjusted to maintain varying temperature, and thermostats, light switches, etc. must not clash with wall coverings or the aesthetic theme. Once these individual concerns are addressed, challenges may lie in the precise coordination of mechanical, electrical and plumbing systems with architectural and structural constraints.

So, what is MEP coordination?

Essentially, MEP coordination is the clash-free integration of all building services within the context of architectural and structural disciplines of a building (steel, concrete, etc.). For sports venues, the MEP challenges are different than for other buildings.

MEP Challenges for Sports Entertainment Venues

• Facility layout with structural and architectural designs, spectator seats, requirements of playing turfs, etc. need to be perfected by industry professionals.
• HVAC equipment must be accommodated in general spaces and the power supply must be uninterrupted for multiple lighting systems across the venue.
• Effective plumbing design is essential for a sports venue where large numbers of spectators can be expected to use rest rooms at the same time. In fact, there is every likelihood that 50 percent of the occupants of a sports entertainment venue use the facilities within the same 30 minutes. Water supply and drainage must operate seamlessly.
• A venue’s geography is another consideration. A French, Spanish, Italian, Russian or English football stadium may vary in architecture and differences due to climate, traditions and national design features. Consequently, the MEP layout will also vary.
• Grandstands, VIP boxes and infield areas present unique fire safety challenges.

Some of the specific design challenges that must be considered during MEP coordination are found below.

Emergency power supply is of utmost importance at a sporting venue. Electrical components and switchgear equipment must be designed without a single faulty point and should handle varying electrical power demands. This could be an oil-powered generator, the grid supply or UPS power with batteries. Large venues would ideally benefit from a diesel generator to run emergency and standby loads. These options need to be integrated with both the other services of MEP and with the other disciplines of the structure.

• Large lobbies in sporting venues sometimes have wide curtain walls, which enable natural light variations. Light photocells can be used to measure ambient light and save energy. Sensors that detect occupancy levels can shut off unnecessary lights and save energy.
• Photovoltaic systems can be used for renewable energy systems and must be factored in to MEP coordination.
• Sports venues have started receiving requests for electric car charging stations. This demand is set to increase, and MEP engineers must consider how these stations work with the rest of the MEP design and the building’s structural and architectural elements.
• Cable trays are a preferred primary pathway due to accessibility and ease of maintenance, but access to cable trays can be tricky because of coordination with ductwork, piping, light fixtures, conduits, etc. 

One of the most vital issues in sporting venues is the size and placement of HVAC units. Extensive ductwork is required to supply and return air, depending on the placement of the units. Typical considerations consist of dehumidification and high latent loads. Vast and varied use of the premises may lead to air distribution challenges. Irregular swings in outside air need to be controlled. 

• Open areas can use passive shading methods and thermal energy storage (TES), so that during times of low demand, cooling can be generated.
• Areas with large occupancy numbers generate corresponding amounts of carbon dioxide. These areas can use carbon dioxide sensors, energy recovery systems and enthalpy economisers.
• Variable air volume (VAV) systems or single-zone VAV can be used in non-bowl systems.
• Large sports venues can integrate variable refrigerant flow (VRF) technology to provide effective condensing units and thereby reduce consumption.
• Smoke venting in stadia with closed roofs need roofs which can open when required. Smoke management can complicate HVAC design, as possible fire sizes must be considered along with whether the smoke should be directed above head height for evacuation safety.
• Due to large occupancy numbers, sports venues require well-ventilated spaces which also consider significant latent loads from all occupants. Humidification and dehumidification features are necessary for air handling systems, and energy can be saved through air side heat recovery. Typically, this is from exhaust air streams through run-around coils, air heat exchangers and heat pipes.
• Venues for hockey games require air to be maintained with low humidity. This may involve sub-cooling air to less than 50 F, eliminating moisture and ensuring comfort.
• In recent times, security is another factor to consider in HVAC design for sports venues. Exterior air intake locations must be secure from chemical threats.
• Rainwater reclamation systems can be used for irrigation and toilet flushing, integrating them with the structural and architectural features.
• Low-flow fixtures can reduce water usage and must be included in MEP design according to the nature of the structure.
• Excessive ceiling heights (anything more than 75 ft) in sporting venues makes automatic sprinkler protection insufficient. Venues have started to integrate deluge-type suppression systems.

The above MEP design requirements must be thoroughly considered and integrated in the process of MEP coordination, a prospect that requires detailed planning and the right tools. One such tool is Building Information Modelling (BIM).

The Role of BIM

Building Information Modelling (BIM) uses tools such as Revit to collaborate and coordinate MEP design on an integrated platform. As these projects are typically carried out by large muti-disciplinary teams, professionals can consult, edit and modify in a shared environment with an organised workflow. Contractors can use 3D BIM coordination software, such as Revit and Navisworks, to identify and prevent potential clashes in MEP design and then use tools, such as Autodesk BIM 360 or Collaboration for Revit (C4R), to work on and share models on the cloud.

Changes in MEP components and layouts may require changes in ductwork designs, fabrication and the process of laying out the systems. It is necessary to fully comprehend the design of each discipline. Hence, MEP components must be set according to the venue’s operations, and MEP engineers use BIM technology effectively to develop a fully coordinated system.

Employing MEP BIM coordination helps create accurate and precise MEP coordination drawings and final construction sets of drawings with vast volumes of data. 

BIM solutions can also help save energy consumption. For example, a sports venue in Germany used 380,000 LEDs for its circular façade using BIM technology, achieving 60 percent more efficiency than conventional lighting. 

Stadia require a flawless collaborative MEP design with the architectural and structural disciplines. BIM technology facilitates this collaborative approach, making it possible to develop impressive sports venues that are fully coordinated, keeping within budget and providing high levels of comfort and safety to all occupants. Tools used in BIM technology can check for clashes and energy consumption to help the building stay cost-effective and energy-efficient, contributing to overall sustainability.

So, what does the finished product achieve with its BIM-assisted MEP coordination? Sporting venues become all that they are meant to be, namely spaces that:

Host World-class Events

Providing spectators and players special experiences depends on interesting, comfortable and reliable structures. This can involve special lighting or retractable roofs that work seamlessly.

Showcase Innovation

Sporting venues cater to a range of different events, from world-class events to concerts to comedians or other events. Multi-use arenas must negotiate site constraints flawlessly, integrating function with aesthetics with effective coordination of MEP systems and architectural and structural features.

Are Cost-efficient and Sustainable

Construction challenges cannot delay opening matches. Imposing structures must be constructed on schedule and function cost-effectively and with efficiency in energy consumption. MEP BIM coordination enables timely and reliable construction.

So, even though effective MEP coordination for new or renovated sports venues may be challenging for MEP engineers and architects, meticulous collaboration, creativity and hard work can help coordinate large-scale building services with high-priced real estate and architectural elements for a comfortable, reliable and aesthetically attractive sports entertainment venue.

Understanding Lux Level Requirements for Commercial Lighting Design

Lighting design plays a key role in commercial buildings which are typically used by people to perform a task or conduct an activity. To achieve their tasks or activities in a workspace, the right amount of illuminance is necessary, over-lighting is as much as a hindrance to accomplishing tasks as under-lighting. Commercial lighting compared to industrial or residential lighting involves higher initial costs, higher maintenance, longer durability and lifespan and higher service costs. To identify the illumination level requirements or lux level requirements of a commercial building, it would be useful to understand the units of measurement of illuminance, the intensity or amount of light and the efficacy of the relationship between lux and lumen.

Illuminance or lux is the intensity of the level of light and ‘luminous flux’ or lumen is the amount of light produced. Lux is the unit of measurement usually measured in foot candles, one lumen is the measurement of the intensity of the light output and is equal to one lux across an area of one square meter. Given an area you may need to illuminate, the measurement of lux helps you identify the output or lumen required. Typically, for an office which is brightly lit around 400 lux of illumination is required and an office space which uses 100W incandescent bulbs in ceiling panels would produce 1600 lumens as the output of light. When a lighting design company designs light fixtures for a large commercial area, the number of light fixtures is usually increased to get higher lumen keeping in mind the lux level requirements.

A primary factor in ensuring efficiency in light design is achieved by balancing lux and watts or managing the amount of power used to produce light. The measurement of energy efficiency or the power required for light fixtures (luminaires) to operate is known as watts or wattage. The rate at which a light fixture converts power to light or watts to lumen is known as luminous efficacy and measured in lumens per watt (LPW). Typically, an office or commercial space with ceiling panels which would use 32W T5 or T8 fluorescent lamps would usually produce 50 lumens/watt.

Lux level requirements are calculated to determine the appropriate number of lights, the type of light fixtures and the best possible commercial lighting solution, based on the size of the office or commercial space, the type of task or activity which will be conducted and the energy efficiency standards required.

In most cases, based on the client requirements of lux levels, office spaces are over-lit and are usually more than rates mentioned in the lighting standard codes and guidelines developed by professional lighting bodies. Lighting consultants and MEP engineering design teams while keeping in mind client requirements must also consider lighting codes and guidelines which mention the minimum lux level requirements that need to be maintained. Several lighting professional bodies have published handbooks and guidelines, some of which include lighting guides published by the Chartered Institution of Building Services Engineers (CIBSE) in the UK, the IESNA Lighting Handbook by the Illuminating Engineering Society of North America and guides and lighting codes provided by the Lighting Council Australia.

To improve energy efficiency and reduce consumption, several countries have presented lighting codes and green building solutions which have made lighting manufacturers develop higher energy efficient light fittings. For offices and commercial spaces, the stipulated lighting watts/m2 is considered to be within the range of 10 to 15 watts/m2. With the increase in the use of LED light fixtures, lighting consultants are required to maintain lighting watts within the range of 5 to 8 watts/m2, while maintaining lux level requirements.

To ensure commercial lighting designs provide higher energy efficiency, lower energy consumption and better control on energy usage, lighting consultants and MEP engineering design teams must consider trending lighting solutions in the industry. From LED fixtures with advanced lighting controls, energy harvesting technologies, interactive lighting to connected lighting, there are several trends which a lighting design company could use to provide high energy-efficiency and customer-centricity in lighting design solutions for commercial spaces.