Top five benefits of HVAC and lighting control integration
Explore chilled beam and lighting control integration.
Understand the benefits of integrating HVAC and lighting controls.
Too often, building systems are designed and constructed as disparate fragments that need to work together. Essential services, such as lighting, heating/cooling, and building controls, compete for limited space, resulting in congested ceilings. In recent years, some of these systems have broken the status quo and joined forces as one integrated component.
One such integration is chilled beams and lighting. The two have quite a bit in common: They are impacted by the number of occupants and daylight present in the room, they keep occupants comfortable and productive, and they try to do this using as little energy as possible. Here are the top five reasons why this concept of integrating chilled beams and lighting systems can be a good choice for some buildings.
Higher energy efficiency
Chilled beams have inherent energy-efficient capabilities that are also present when integrated with lighting. Traditional HVAC systems use air, whereas chilled beams take advantage of water’s increased volumetric heat capacity to regulate a space’s temperature. It’s because of this that they can typically reduce HVAC energy consumption by up to 50% to 60% as compared with traditional systems.
But chilled beam systems, like other HVAC systems, must be designed properly to achieve full energy-savings potential. The key is to minimize the primary airflow rate to transfer as much of the space’s sensible cooling load onto the more efficient waterside of the system.
It is also important to maximize the induction rate. Here’s how it works: Active chilled beams have two distinct cooling components—the primary air and the water coil. Air induced from the space is cooled by the chilled-water coil and is affected by the inlet pressure and nozzle size (the smaller the nozzle, the greater the induction rate). Low-pressure zones are created around the jets of primary air as they exit the nozzles. The low-pressure zones induce room air over the chilled-water coil, which then cools the air and provides sensible cooling. A higher induction ratio shifts more of the cooling load onto the water coil, which can lead to greater energy savings. (See Figures 1a and 1b).
Lower total lifecycle costs
Beyond lower energy costs for building owners, there are also reduced installation costs associated with integrated systems. When both a space’s lighting and HVAC systems are in one component, there’s decreased complication during install. A common perceived hurdle to adapting this kind of integrated system is who does the install, a mechanical contractor, an electrician, or the sheet metal contractor? The answer is that the mechanical contractor usually installs the beams first and the electrical contractor then makes the final electrical connections.
Integrated lighting and chilled-beam systems also have the potential to reduce building height. As chilled-beam systems are designed with around 70% less air than traditional all-air systems, the ductwork is considerably smaller, which often results in a slab-to-slab heat reduction of 12 in., leading to more flexibility in building construction.
Even beyond the initial installation, chilled beams continue to produce opportunities for savings. Maintenance costs decrease because chilled beams don’t have blowers, motors, filters, or condensate pumps. Instead, they rely on dry coils to operate, which only require cleaning once every 2 to 10 years, resulting in lower lifecycle costs.
Better indoor environment for occupants
A comfortable indoor environment should be a high priority when choosing and designing a building’s HVAC system. Traditional systems can have unpredictable ventilation performance (where some areas of the building are overventilated and others are underventilated), difficulty mixing during part-load conditions, and imprecise humidity control.
Chilled beams are often paired with dedicated outdoor-air systems (DOAS), which ensure all zones of the building receive correct ventilation and dehumidification at all times. Chilled beams allow the sensible cooling (and heating) to be decoupled from the ventilation and dehumidification requirements of the building. Precise control of these three elements reduces energy consumption, as over-ventilation and dehumidification is far less likely. They also typically operate at a constant volume, which allows for better mixing and an even temperature across the room.
More enhanced aesthetics
HVAC is traditionally thought of, from a design standpoint, as a system that must be incorporated out of necessity and not because of what it adds visually. The integration of lighting and chilled beam reduces the visual mass of the systems in the ceiling plane, allowing for a less cluttered look without sacrificing a quality HVAC system. The product itself can have a cleaner look, as well, with sleek designs that are seamlessly incorporated into ceiling plans. Some systems are developed with input from architects on what design aspects are appealing to building owners.
Future potential for integration and innovation
One of the most exciting parts of this system integration is that it’s only the start of system integration. Future possibilities will expand beyond just lighting and HVAC to encompass a range of possibilities, from building safety requirements like fire suppression, security systems, and carbon monoxide detectors to other building benefits like occupancy sensors and sound bars for intercom systems or other sound-projection needs. Not only will the products integrate, but the associated controls will as well.
For example, occupancy sensors can monitor when and how many people are in a space to adjust the load setting accordingly or additional sensors can monitor the strength of sunlight and lower lights as needed to increase energy efficiency. Eventually, these will also integrate into building control systems and the Internet of Things (IoT) to further allow different systems to communicate and work together.
Future innovations like these can lead to additional efficiencies in installation costs because these innovations will prioritize a building’s design and function as a whole rather than approaching each system individually.
Considering humans spend 90% of their time indoors, it makes sense that our building needs have evolved and our spaces have become smarter, thanks in part to IoT. Our building systems need to keep pace, too. Consider a holistic building systems approach that integrates multiple components to optimize performance and create the best possible indoor environment.
Nick Searle, a chief engineer with Titus-HVAC, has more than 20 years in HVAC application experience in a range of fields including noise control engineering, air distribution, and most recently, air/water systems. Originally from the U.K., Searle has worked in the U.S. since 2006 supporting engineers, owners, and architects with the design of chilled-beam systems, and he has been involved with many of the first chilled-beam systems to be installed in North America. He is a frequent speaker at ASHRAE chapters and is a co-instructor for the 2018 ASHRAE Learning Institute course, Understanding and Designing Chilled Beam Systems.