Cities aim to have regenerated buildings and to leverage data to optimize energy consumption and the use and management of resources in buildings and utilities: waste, water, and energy.
Smart buildings clearly being efficient
The World Green Building Council defines a green building as one that “in its design, construction or operation, reduces or eliminates negative impacts, and can create positive impacts, on our climate and natural environment; preserves precious natural resources and improves our quality of life.” Given the pressure on cities to act on climate change, green buildings are going to invade our urban centers. Besides being built with sustainable and ethical materials, they will be energy, water, and resource-efficient, environmental-friendly by design, and capable of producing their own energy (electricity prosumers). Vertical and rooftop gardens will foster quality of life and a suitable environment for those who live in them or use them.
Wireless sensors offer huge advantages
Wireless radio sensors form the basis for such smart spaces because they collect the required data in a maintenance-free way. The advantages of wireless sensors are obvious: They can be flexibly installed in a room, and the system can be expanded with additional sensors at any time without having to open walls and use cables. However, it is hugely beneficial for these wireless sensors to be battery-free because it’s no secret that batteries contain hazardous substances that are bad for our environment. In addition to that, copper is also becoming increasingly expensive.
EnOcean has chosen a more sustainable approach for its wireless sensors: they obtain their energy from movement, light, and temperature differences according to the principle of energy harvesting and therefore require neither cables nor batteries for smooth operation. The combination of wireless and energy harvesting enables new applications entirely without maintenance requirements and battery waste.
Benefits of smart buildings
Automatically controlled shading systems go a step further, responding to changes in outdoor and indoor temperature conditions over the course of a day without relying on
human input. Solar-adaptive shades work in the same way in response to the position of the sun. These smart shades rely on sensors that measure indoor and outdoor ambient
temperatures or the sun’s position and radiation, automatically adjusting their height to manage the amount of light and heat entering the building. These devices can be integrated with lighting and building management systems for centralized control. When added to a lighting retrofit project to maximize daylighting, smart shades offer an additional 10% savings in lighting energy use.
Barriers to their adoption
Advanced window glass and films can save even more energy, and passive glass technologies (such as low-E glass) are readily available. Traditional glass has bronze or gray tinting. Advances in tinting now achieve a wider color spectrum, permitting visible light to pass through to the interior of the building while reducing solar heat gain. Recent developments in window films, such as dual reflective, solar control, and daylight
redirecting films, can be applied to existing untinted windows to achieve the shading benefit of tinted glass. These simple, moderately priced advances in technology commonly daylighting designs in commercial building retrofits and have the added benefit of reducing solar heat gain and glare. A window film retrofit study on buildings in California found an average return on investment (ROI) of 39% for films applied to single-pane windows and 25% for double-pane window applications.
Conservation of energy is a definite must!
Building automation is the most expensive technology in this space. As mentioned previously, the industry-accepted cost of a traditional BAS ranges from $1.50 to $7.00/sq. ft., with average whole-building energy savings ranging from 10% to 25%. Because wireless, cloud-based EIS requires less hardware than a typical BAS, they are advertised as costing up to 30% less to install. However, a cloud-based BAS typically requires
subscription service costs that also must be considered.
Because cloud-based energy monitoring and control systems are a relatively recent addition to the building controls market, reliable cost data was not readily available. As a result, we distinguish between traditional BAS, which has well-documented costs, and a cloud-based monitoring system, which few researchers besides Lawrence Berkeley National Laboratory have studied. In reality, building owners face a wide variety
of costs for BAS. If the building already contains a traditional BAS, adding cloud-based remote monitoring might entail only a small incremental cost. If the building has no control or monitoring systems, installing the required base of sensors and controls will entail higher costs. In terms of energy savings, how do cloud-based monitoring and control systems stack up against conventional BAS? Cost savings for whole-building BAS range from 5% to 15% on the low end and 20% to 30% on the high end (Roth et al. 2005). However, when a cloud-based EIS is overlaid on an existing BAS, the benefits of combined analytics and controls can yield energy savings of 10–30%.
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