Gulf Construction Online - Towards sustainable systems in the region

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Towards sustainable systems in the region

DR ARCHIBONG ARCHIBONG-ESO of the University of Birmingham Dubai provides an insight on how to aim for energy savings and develop sustainable HVAC systems in the region.

01 April 2020

Data from British Petroleum’s statistical review of world energy 2019 shows that the world’s primary energy consumption grew by 2.9 per cent over 2018 figures, the steepest since 2010. The Middle East, which is home to 3.3 per of the world’s population, accounted for 6.9 per cent of this growth.

Buildings account for 40 per cent of primary energy consumption with 48 per cent of this attributable to heating, ventilation and air-conditioning (HVAC) systems, according to the US Energy Information Agency estimates.

As major energy guzzlers, HVAC systems in buildings are a prime target for energy savings, reduced environmental impact, and hence, sustainability. Sustainable HVAC systems actively seek to minimise or eliminate environmental impact, increase energy efficiency during operation/maintenance (and in the manufacturing of its components), and should have at least some of their components recycled or reused at end of life.

Sustainable HVAC systems in the building industry could be achieved through a holistic approach, right from the initial concept design stage, through construction, operational life and the final decommissioning of the building. It is important to weigh heavily on how these stages each affect the HVAC system in order to make it more sustainable. Information such as building function, requirements, usage, operation, management, climatic condition, applicable building codes, statutory regulations, etc, should be utilised in the decision-making as to the choice and the initial estimates required to size HVAC systems.

Of particular importance to the holistic approach is an understanding of how the HVAC system integrates with other building components. Integrated system thinking allows for opportunities and measures, which could make the system more sustainable, to be identified and/or developed. This is even more useful when done earlier on in the concept design stage.

Value of regulation

Regulation could also play an important role in sustainable HVAC systems. National standards and codes such as the Abu Dhabi International Building Codes, Dubai Universal Design Code, and the Saudi Building Code in the region ensure compliance by the building industry and should be viewed as a minimum standard for building construction.

Ensuring certain sustainable practices, such as making it statutory to use HVAC equipment that is manufactured, at least in part, from recycled materials, and which complies with pre-defined energy ratings, could be hard coded into national building standards.

Digital developments

Computer simulation is one way to ensure a more accurate sizing of HVAC equipment, optimum installation points, and the use of equipment with propensity for low greenhouse gas emission.

Sustainable HVAC could rely on devices that are powered by artificial intelligence (AI) and machine learning (ML) and driven by real-time data.

Some of these technologies, such as the demand-controlled ventilation (DCV) and residential integrated ventilation-energy controller (RIVEC) reported by Lawrence Berkeley National Laboratory in California, can help modulate indoor air quality (IAQ) based on key ventilation parameters, while ensuring a more efficient and sustainable ventilation for buildings.

Meanwhile, smart thermostats, capable of adjusting the indoor temperature of the HVAC systems based on outdoor temperature, number of occupants in the living space, and other factors, could help deliver a more sustainable HVAC system.

The systems

HVAC systems are energy intensive, since they comprise many mechanical devices including compressors, boilers, radiators, circulating pumps, pipes and more. Several approaches can be used to achieve sustainability in these devices.

Currently, most of these devices undergo either breakdown or scheduled maintenance. Embracing data-driven predictive maintenance could ensure a more effective system, reduced energy consumption, reduced downtime, all of which could lead to a more sustainable system.

As an example, air filters are important components in ensuring optimum functionality of HVAC systems. Clogged filters could lead to sub-optimal HVAC system performance and high energy consumption. Presently, the maintenance strategy for filters is to schedule maintenance after predefined days of usage. A predictive maintenance that accounts for operating parameters could help enhance maintenance, reduce cost and minimise energy consumption.

The HVAC system could also aspire to be ‘greener’ and more sustainable through the effective use of natural ventilation, by reusing waste heat, and/or by using renewable resources such as geothermal and solar energy.

A more sustainable HVAC system would use the cogeneration model, where ‘waste heat’ from an HVAC system is utilised for heating. This ensures that the energy that would have hitherto been used in heating is eliminated. Over the lifespan of the system, the amount of energy conserved could be very significant, resulting in large energy savings, reduced greenhouse gas emissions and improved bottom line for building owners.

Research & education

Robust research on the energy use in the built environment in the Middle East should be pursued between industry and academia to support a more general policy shift by governments in the region, and could help to deliver a more sustainable HVAC system for the building industry. Policies that look to developing a sustainability index whereby buildings are awarded ratings based on sustainability performance, or integrating certain sustainability indices into building codes, or encouraging HVAC designers and manufacturers to strongly consider the use of recyclable and biodegradable materials in manufacturing, could all have a profound effect.

Demand-side management, which takes into account the consumption habits of users of HVAC systems, also has its merits. Policy influence in energy pricing is a typical example that has been effectively implemented by Dewa, whose tariff regimes increase proportionally with energy consumption and carbon dioxide emissions.

In terms of talent, training undergraduate engineers to be more sustainably compliant in their design and practices will help in a shift towards a more sustainable construction industry. An example of this is the University of Birmingham Dubai’s Integrated Design Project (IDP) module.

This module was designed together with a leading construction firm, and requires students to design huge engineering infrastructure that moves (such as moving bridges, observatory wheels, retractable stadium roofs). One of the key aspects emphasised during the students’ project briefing and design consultancy sessions is sustainability, with final designs being required to satisfy at least five of the UN Sustainable Development Goals (SDGs). This way, students acquire sustainability skills through classroom teaching and project-based learning.

As a final note, we must remember that the responsibility for a more sustainable world lies with all of us.

• Dr Archibong Archibong-Eso is a lecturer in Mechanical Engineering at the University of Birmingham Dubai.