Introduction
The topic of energy efficiency has become the most distinctive during the last decade. Office buildings, as the ones that consume more electricity compared to households, remain at the center of discussion. Modern architectural bureaus suggest strategies that allow halving the consumption of electricity through the use of modern systems of electric lighting and daylight. This paper aims to discuss how corporate office buildings can be upgraded to increase energy-efficient lighting that utilizes both natural and electric sources as well as lighting controls.
Utilizing Natural and Electric Sources
New architectural solutions capture the attention of connoisseurs and lovers of architecture. Quirky forms combined with high functionality seem to have become a type of new construction. However, when it comes to energy efficiency, beauty, and aesthetics do not necessarily translate into practicality. For example, rooftop gardens look very attractive, but they do not make a significant contribution to solving the problems of carbon emissions. At the same time, daylight lighting cannot always replace electric lighting, as in open office spaces, an excessive number of lux from daylight causes complaints from employees about the deterioration of vision and general working conditions. Therefore, architects and engineers follow a method of simple solutions that are not necessarily related to aesthetics.
One such typical solution is the use of daylight harvesting lamps for indoor lighting. Shankar et al. (2020) note that since “artificial lighting contributes significantly to total energy consumption, it must be reduced, especially in zero-energy buildings (ZEBs)” (p. 2). Since the collection of daylight can violate the visual preferences of residents if not properly regulated, scientists suggest artificial energy-efficient systems. Scholars propose to use an intelligent LED lighting system powered by low voltage direct current (LVDC) that functions by harvesting daylight. Such a system makes it possible to control the amount of daylight and preserve the visual preferences of users (Shankar et al., 2020). Equally important, measurements showed 26.11% energy savings with LVDC compared to the traditional system in the first month. In the following months, energy savings were 61-69% on clear days and 42-55% in cloudy conditions (Shankar et al., 2020). This example demonstrates how easier-to-implement and more technologically sophisticated solutions lead to simple and immediate results in energy saving.
Interestingly, excessive lighting can lead to visual discomfort for workers. Research participants who started working in a green building with a high degree of glazing complained about unpleasant glare at workplaces near windows and too much light in open office spaces (Kwong, 2020). The results showed that the interior spaces had the problem of glare, which was solved by installing blinds, and from 10:00 to 15:30, daylight was sufficient (Kwong, 2020). In other words, the use of daylight is possible, but only if the standards of illumination are met and side effects such as glare are considered. In general, scientists agree that daylighting can significantly reduce energy consumption.
Heating and ventilation are no less important sources of electricity consumption. Therefore, green buildings make maximum use of ecological sources of heat storage and cooling. Indoor temperature is affected by the type of materials from which the walls are built, the presence of balconies, and an effective ventilation system that allows air to circulate without losing heat in winter and helps to cool in summer.
Scientists have also studied how the number of floors and the age of buildings affect heating and ventilation methods. The results showed that spaces below the 5th floor and above the 21st floor had a 137% and 42% increase in electricity and fossil fuel use, respectively, resulting in a doubling of average carbon emissions (Godoy-Shimizu, 2018). Therefore, when locating office premises, this factor can be considered and the lower and upper floors should be allocated to technical premises. Interestingly, scientists established the importance of conditioning when artificial conditioning is associated with increased superficiality. At the same time, new buildings were recognized as less efficient due to the higher intensity of electricity consumption.
The scientists analyzed common ways of adapting buildings to energy efficiency requirements. They identified that adaptation projects are implemented in the design and planning, construction, and post-construction phases (Erebor et al., 2021). Strategies included “landscape designs, site selection, building orientation, building plan, and appropriate spatial organization” (Erebor et al., 2021, p. 2). The most popular were renewable integration strategies such as solar panels, building envelope systems, building orientation, and daylighting design.
Lighting Controls
Interestingly, the lighting system can include lighting control implemented by maintaining appropriate illumination levels. Wagiman & Abdullah (2018) note that “the lighting system accounts for 20% to 45% of the total energy used in buildings” (p. 195). Control of illumination levels presupposes compliance with the European standard EN12464-1 (Erebor et al., 2021). Since the actual light levels usually exceed the required ones, the control systems allow significant savings in electricity consumption (Erebor et al., 2021). This is possible due to the installation of symmetrical grids for the location of lamps, and dimming control.
Conclusion
Therefore, it was explored how to improve corporate office buildings to have more energy-efficient lighting systems that use both electric and natural sources. Natural lighting may not always be an adequate substitute for electric lighting and should be used with caution. Electric lighting control systems and daylight harvesting lamps allow significant savings in electricity consumption. Equally important, engineers and architects must use planning, building orientation, and ventilation to reduce consumption and consider that lower and upper floors consume more energy.
References
Erebor, E. M., Ibem, E. O., Ezema, I. C., & Sholanke, A. B. (2021, March). Energy efficiency design strategies in office buildings: A literature review. In IOP Conference Series: Earth and Environmental Science, 665(1), 1-12. IOP Publishing.
Godoy-Shimizu, D., Steadman, P., Hamilton, I., Donn, M., Evans, S., Moreno, G., & Shayesteh, H. (2018). Energy use and height in office buildings. Building Research & Information, 46(8), 845-863.
Kwong, Q. J. (2020). Light level, visual comfort, and lighting energy savings potential in a green-certified high-rise building. Journal of Building Engineering, 29, 1-10.
Shankar, A., Krishnasamy, V., & Chitti Babu, B. (2020). Smart LED lighting system with occupants’ preference and daylight harvesting in office buildings. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 1-21.
Wagiman, K. R., & Abdullah, M. N. (2018). Intelligent lighting control system for energy savings in office buildings. Indonesian Journal of Electrical Engineering and Computer Science, 11(1), 195-202.
