OWSD Nigeria National chapter presents Are Users the Solution to Sustainability? Unveiling the Insight into Energy Efficiency and User Comfort in Buildings
August 31, 2024
OWSD Nigeria University of PortHarcourt Branch Series of Scientific Communications:Eziaku Rasheed on Are Users the Solution to Sustainability? Unveiling the Insight into Energy Efficiency
Are Users the Solution to Sustainability? Unveiling the Insight into Energy Efficiency and User Comfort in Buildings
By
Dr Eziaku Rasheed, School of Built Environment, Massey University
Introduction
As the world grapples with the urgent need for sustainability, buildings play a pivotal role in shaping our energy consumption patterns and, ultimately, our environmental impact. Globally, buildings account for approximately 39% of carbon emissions, with operational carbon contributing 28%. In New Zealand alone, the built environment accounts for around 20% of the country's carbon emissions. As a result, achieving a balance between occupant comfort and energy efficiency has become a critical challenge in pursuing sustainable building design and operation.
In this presentation, I discussed whether building occupants (users) can be key to achieving sustainability by focusing on the balance between energy efficiency and user comfort in buildings. I examined how users' behaviors and preferences impact energy use and whether empowering them to manage their comfort could close the gap between predicted and actual energy performance. Subsequently, I presented an experimental case study wherein my research team proved that user comfort could be improved without an increase in energy use in an office environment. The solution tested was empowering users to manage their individual comfort with the support of an Internet of Things (IoT) system.
The discussion highlights the potential role of users in contributing to more sustainable building operations and the role technology can play in supporting it. Easy-to-do energy-wise practices are presented as a step toward more energy-positive building operations.
The Challenge: Energy Efficiency vs. User Comfort
The building industry has seen considerable technological advancements to enhance energy efficiency, such as smart sensors, adaptive HVAC systems, and improved building envelope designs. However, despite the exhausted benefits of these advancements, a significant dilemma persists: increased user comfort often leads to higher energy consumption. For instance, achieving user comfort in fully air-conditioned spaces is limited by the variability in users’ expectations and satisfaction. For instance, studies show that occupants of air-conditioned spaces are often uncomfortable with reduced productivity and satisfaction levels as these spaces are commonly too cold, especially in office spaces [Onyeizu, 2014; Rasheed et al., 2024]. Regarding energy use, Byrd et al. [2022] noted that reducing air conditioning demand in buildings will improve energy security and reduce greenhouse gas emissions. This indicates that further advancements in HVAC systems will not necessarily lead to the expected improvements in desired outcomes for comfort and energy efficiency. This paradox is a key factor contributing to the performance gap between predicted and actual energy use in buildings. The question then arises:
How do we balance these competing needs (energy efficiency and occupant comfort)?
Indoor Environment Quality (IEQ) and Its Impact on Occupants
A primary focus of recent research is Indoor Environment Quality (IEQ), which encompasses lighting, ventilation, thermal comfort, and noise levels. Studies have demonstrated that poor IEQ can lead to various health issues, including respiratory problems, stress, and decreased productivity. For instance, in New Zealand, issues such as fuel poverty and inadequate housing conditions have been linked to higher rates of asthma, lead poisoning, and other health conditions.
IEQ standards are designed to create acceptable living and working conditions by setting benchmarks for factors like lighting (320-500 lux), ventilation (CO2 levels below 800ppm), and thermal comfort (a minimum of 18°C). However, achieving these standards does not always lead to the desired outcomes, particularly regarding energy use. For example, while comfort is a significant driver of energy consumption, it does not always correlate with increased productivity. Studies have shown that productivity can decrease as the number of occupants in a space increases despite improvements in comfort.
Occupants’ Behaviour and Its Impact on Energy Use
Research has shown that users’ energy behaviors can account for up to 80% of a building’s operational energy use, and these behaviors play a significant role in the energy performance gap. In essence, while building systems can be designed for maximum efficiency, how occupants interact with these systems can significantly impact overall energy consumption.
Likewise, research has attempted to find solutions to reduce users’ energy behavior. In New Zealand, Stephenson [2010, 2015] identified opportunities for behavior change through cognitive norms, energy practices, material culture, and external influences on energy consumption behavior. Weerasinghe et al. [2023] recommended creating an intelligent environmental control system loop with eco-feedback as important for establishing occupant-centric buildings or features.
Nigeria’s Energy Challenges: A Case Study in Contrasts
While New Zealand grapples with balancing comfort and energy efficiency, Nigeria faces different challenges that impact energy use and occupant comfort. Nigeria's energy landscape is characterized by limited access to electricity, inadequate infrastructure, and an overreliance on fossil fuels. These challenges are compounded by environmental impacts such as pollution and deforestation, as well as energy theft and vandalism, which further strain the country's energy resources.
In Nigeria, the lack of reliable electricity often forces individuals and businesses to rely on generators powered by fossil fuels, contributing to both financial burdens and environmental degradation. This overreliance on generators increases greenhouse gas emissions and limits the ability of buildings to provide consistent comfort levels for occupants. The economic constraints many Nigerians face also mean that investments in energy-efficient technologies and building retrofits are often out of reach, exacerbating the energy inefficiency of the built environment.
Despite these challenges, Nigeria has opportunities to improve energy efficiency through adopting energy-wise behaviors and implementing cost-effective solutions. For example, simple measures such as improving insulation, using energy-efficient lighting, and educating occupants about energy-saving practices can significantly affect energy use and comfort levels. Additionally, leveraging local materials and traditional building techniques that naturally reduce heat gain can help create more sustainable and comfortable living environments.
Users’ Energy-Wise Behaviours: The Missing Link?
Given the significant impact of occupant behavior on energy use, empowering users to adopt energy-wise habits is crucial for bridging the gap between comfort and efficiency—whether in New Zealand, Nigeria, or elsewhere. Energy-wise behaviors are everyday practices that individuals can adopt to reduce their energy consumption, such as turning off unused appliances, using energy-efficient devices, and optimizing natural light. These behaviors lower energy bills and contribute to reducing greenhouse gas emissions and minimizing environmental impact.
A critical aspect of this approach is enabling building occupants to have more control over their environment. Recent studies have explored the integration of the Internet of Things (IoT) into Post-Occupancy Evaluation (POE) systems to provide real-time feedback on indoor air quality (IAQ) and other environmental factors. These systems can enhance comfort and energy efficiency by allowing occupants to make at-the-moment adjustments based on real-time data, such as altering ventilation or lighting.
Experimentation and Key Findings
Our research team experimented with integrating IoT into a building's POE system to investigate how real-time feedback could influence occupants' perceptions of comfort and IAQ. The study found that participants' perceptions of air stuffiness were significantly reduced after they took energy-wise actions, even when CO2 levels were within acceptable ranges. This highlights the importance of empowering occupants to actively participate in managing their environment rather than relying solely on automated systems.
Figure 1. Conceptual framework of the integrated IoT platform in POE. Source: Rasheed et al., (2024).
Moreover, the study revealed that individual control over environmental factors like temperature and ventilation could lead to a more personalized and satisfying indoor experience. This approach not only enhances comfort but also has the potential to reduce energy use, as occupants can make adjustments based on their specific needs and preferences rather than defaulting to high-energy solutions.
The Way Forward: Empowering Occupants for Sustainable Buildings
To close the comfort-energy performance gap, it is essential to recognize building occupants as integral players in achieving sustainability goals. This requires a shift in focus from purely technological solutions to strategies incorporating user behavior and empowerment. By providing occupants with the tools and knowledge to manage their comfort in an energy-efficient manner, we can create sustainable and comfortable buildings.
In countries like New Zealand, where energy efficiency is a key focus, and in Nigeria, where energy access and infrastructure pose significant challenges, the principles of energy-wise behavior can play a transformative role. Whether through IoT-enabled systems, education on sustainable practices, or the adoption of energy-efficient technologies, empowering users to take an active role in managing their energy consumption is crucial.
In conclusion, the balance between energy efficiency and user comfort is not only feasible but necessary for the future of sustainable building design. As research continues to explore the interplay between these factors, it is clear that empowering occupants to take an active role in managing their environment is critical to achieving energy savings and improved indoor living conditions. As we move forward, the challenge will be to develop systems and strategies that integrate these elements, ensuring that our buildings meet the dual goals of sustainability and comfort across diverse global contexts.
References:
Byrd, H.; Matthewman, S.; Rasheed, E. Air-conditioning in New Zealand: Power and policy (2022). Build. Cities, 3, 1–9. [Google Scholar] [CrossRef]
Onyeizu, E. (2014). Can Architecture Increase Productivity? A Case of Green Buildings. Ph.D. Thesis, The University of Auckland, Auckland, New Zealand. [Google Scholar]
Rasheed, E.O.; Khoshbakht, M.; Baird, G. (2024) “Do office workers’ comments corroborate the ratings they give their buildings?” A qualitative analysis of comments on operational factors in the workplace. Facilities, 42, 274–320. [Google Scholar] [CrossRef]
Rasheed, E., Wang, K., Hashemi, A., Mahmoodi, M., & Panchalingam, K. (2024). Integrating Internet of Things (IoT) Approach to Post-Occupancy Evaluation (POE): An Experimental At-the-Moment Occupant Comfort Control System. Buildings, 14(7), 2095. https://doi.org/10.3390/buildings14072095
Stephenson, J.; Barton, B.; Carrington, G.; Gnoth, D.; Lawson, R.; Thorsnes, P. (2010) Energy cultures: A framework for understanding energy behaviours. Energy Pol., 38, 6120–6129. [Google Scholar] [CrossRef]
Stephenson, J.; Barton, B.; Carrington, G.; Doering, A.; Ford, R.; Hopkins, D.; Wooliscroft, B. (2015). The energy cultures framework: Exploring the role of norms, practices, and material culture in shaping energy behaviour in New Zealand. Energy Res. Soc. Sci. 7, 117–123. [Google Scholar] [CrossRef]
Weerasinghe, A.; Rotimi, J.; Rasheed, E.O. (2023). Modelling of underlying social psychological effects on occupant energy-related behaviours. Build. Environ., 231, 110055. [Google Scholar] [CrossRef]
