Smart Buildings Use Less Energy

By Rick Rys

Technology Trends

All buildings use energy, but there are many ways to use less energy and still achieve the required functions. Buildings and individual rooms within buildings have different purposes. In an industrial environment, for example, consider the different energy requirements for business offices, break areas, warehouses, clean rooms, control rooms, and the plant or factory floor. Obviously, some of these spaces require specialized equipment to perform the required functions. So how can smart building use less energy?

The construction and nature of the building use largely determine the energy required. New building codes require new or retrofitted buildings to be much more efficient than standards just 10 years ago. Most jurisdictions in the US now use building codes based on the International Building Code (IBC) developed by the International Code Council (ICC). Even more efficient building standards like “passive house” are common in Europe, and have stricter energy use requirements than the current US or IBC building codes. New buildings require consumption of raw materials for construction, and these raw materials consume resources and energy. The LEEDS (Leadership in Energy and Environmental Design) is one of the most popular green building certification programs used worldwide. Developed by the non-profit U.S. Green Building Council (USGBC), it includes a set of rating systems for designing, constructing, operating, and maintaining green buildings, homes, and neighborhoods that aims to help building owners and operators be environmentally responsible and use resources efficiently.

Smart Buildings Use Building Automation Systems.png

Smart Buildings Use Building Automation Systems (Source: Wikipedia)

Even a “dumb” building would have equipment that meets the goal of the building such as regulating the temperature and switches for lighting. Equipment like HVAC systems, boilers, and air handlers will come with a functioning control system. The amount of energy used by a building is largely determined by the design of the building, but the equipment used for the building to achieve its functions has a big role too. The choice of an oil or gas fired boiler, a pellet stove, a geothermal heat pump, or a mini-split air source heat pump determine the type of energy consumed and, depending on the efficiency of the equipment, has a big impact on the amount of energy consumed. To design and operate a building to use less energy requires considerable understanding of how the building and all of the equipment in that building work in actual operation.

What is a Smart Building?

So, what makes a building smart? Definitions vary slightly, but a smart building is any structure that uses automation to control the building's operations including heating, ventilation, air conditioning, lighting, security and other systems. Smart implies that all systems and IoT devices communicate and work together as an integrated BAS (Building Automation System). Smart also implies that the building will work efficiently and harmoniously with the environment and infrastructure it is placed in. Smart buildings are a key element that makes a Smart City, and a smart electric grid will have a big impact how a smart building is configured. Smart buildings need to interface with other infrastructure with compatible communications systems. This contrasts with each piece of equipment operated with a local control system that is unaware of how other systems are operated. Achieving efficient operation requires a detailed understanding of the state of the building and its equipment; how the building is used daily, weekly, and in each season; and how to operate equipment in the most efficient manner. This includes operating effectively when things go wrong, like a power failure.

Operating buildings requires measuring various parameters, and actuating control system outputs to achieve various targets or setpoints. A key place to start is with smart metering of all utilities - electric power, water, gas, fresh air, wastewater, and any other utility for special building functions, like oil or biomass for heating, diesel fuel for generators, and the production of any energy such as a roof mounted PV solar system would provide. This provides the “big picture,” and is essential for an energy balance. Many other measurements are also needed, such as interior and/or exterior temperatures, humidity levels, or dew points; occupancy; light levels; and various fluid pressures, levels, and flowrates. To regulate buildings efficiency in real time, you need to collect all data from all sources. What data is needed and how it is used is the key problem, and this is likely to change in the future as technologies like utility demand response mature. Collecting the right data with the appropriate analytics can pinpoint maintenance issues and help identify building issues that can drive the appropriate modifications to the buildings or equipment.

A second key point is that all stakeholders should have access to the information they need. A building with a modern BAS system can provide the appropriate data to facilities engineering, facilities maintenance, contractors, guest and regular occupants of the building, and building managers. Various stakeholders should be able to make adjustments consistent with their respective roles. Regular occupants should be able to make climate and lighting adjustments especially if they are working at abnormal hours, or perhaps the BAS should sense the occupants and make adjustments automatically. Managers should have a form of a dashboard that enables them to see utility costs and problem areas; facilities people often need remote access to make adjustments or to update control configuration or BAS software. Considering that most people now have smart phones or other internet connected devices the communication infrastructure has come a long way. The proliferation of new IoT sensors, edge gateways, and open BAS systems makes it easier than ever to connect people to the buildings they own or visit. Buildings provide physical security with locked doors or access badges, so IT would be involved with the cybersecurity aspects of the BAS.

EIA statistics show that in 2016, the residential and commercial sectors in the US consumed about 40% (or about 39 quadrillion BTUs) of total energy in the country. As such, the opportunity to make buildings use less energy is enormous. While better design and more efficient equipment are most important, implementing new sensors and control systems could make our existing buildings run more efficiently. Proper application of BAS systems IoT devices, edge gateways, business networks, wireless networks, and cloud computing resources by skilled people is what makes a building smart. Considering the age and state of our buildings, and the advancement of building design, building components, building HVAC, IoT devices, building management systems, and the enormous waste of energy and resources used for buildings, there is considerable room for buildings to get even smarter.

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