Energy Efficiency and Thermal Comfort: A Core Issue in Green Building Development in Vietnam

ENERGY EFFICIENCY AND THERMAL COMFORT – THE CORE ISSUE IN GREEN BUILDING DEVELOPMENT

M.Sc. Arch. Tran Thanh Vu - Edeec & ISSER

In developed countries, the issue of energy efficiency, closely related to energy security, was recognized very early on. They proactively introduced mandatory laws and regulations for design to ensure energy-efficient use through Building Codes and Standards. These requirements are mandatory when submitting construction permit applications. Later, the trend of green buildings emerged, but on a voluntary basis. However, compliance with minimum energy requirements has intrinsically been integrated into green rating systems. Therefore, energy saving and code compliance remain mandatory, while achieving green certification is voluntary. In this paper, we focus on clarifying the core issue in green building development: energy efficiency and thermal comfort.

ENERGY EFFICIENCY - VIETNAM AND INTERNATIONAL CONTEXT

Over the past several decades, the Vietnamese government has shown increasing interest in national energy efficiency. Although positive changes have occurred, the overall energy efficiency of the economy remains low compared to neighboring countries. To generate 1 USD of GDP, we consume energy 2.5 times higher than the world average, 1.3 times higher than China and India, 1.7 times higher than Malaysia, 1.9 times higher than Thailand, 2.6 times higher than the Philippines, 3.8 times higher than Japan, and 4.7 times higher than Singapore.

Therefore, improving energy efficiency is extremely urgent to enhance competitiveness and the overall efficiency of the economy.

The construction and building operation sector significantly impact national energy efficiency, with building operations accounting for approximately 35-40% of the total national electricity consumption.

Some statistics and surveys published by the Ministry of Industry and Trade show that about 20-25% of energy used in buildings is wasted. This means wasting about 20% of the 40% total electricity consumption, which is more than double the renewable energy output as of the end of 2020.

In developed countries, the issue of energy efficiency, related to energy security, was recognized very early on. They proactively introduced mandatory laws and regulations for design to ensure energy-efficient use through Codes and Standards. These requirements are mandatory when submitting construction permit applications.

Later, the voluntary green building trend emerged, but compliance with minimum energy requirements has intrinsically been integrated into green rating systems. Therefore, energy saving and code compliance remain mandatory, while achieving green certification is voluntary. Simply put, all green certification systems refer to other industry standards and codes, particularly requirements regarding HVAC (heating, ventilation, air conditioning), thermal comfort, lighting, energy, etc. Green buildings will require adherence to these requirements in a way that exceeds the minimum requirement by 3-10% as a prerequisite (failure to meet this means failing the certification without considering other criteria).

The Lotus certification - Based on the energy prediction model compliant with QC09:2017 minimum level.

The scoring system for LEED is more complex than Lotus; points vary depending on the building type, and additional point thresholds are pre-established, referencing the ASHRAE 90.1 standard.

In France, energy efficiency requirements for buildings were introduced after 1973, following the oil crisis. Currently, thermal and energy regulations are constantly updated and gradually tightened according to advancements in materials, technology, and equipment, with the goal of achieving positive energy buildings. This means that over a weather cycle (1 year), the building generates energy rather than consuming it in total. To achieve this, France’s building energy regulation (RT – Règlement thermique) has been continuously updated through many versions; the latest is RT 2020 – BEPOS - Batiment à énergie positive.

For a comparative perspective, Vietnam has had energy efficiency regulations since 2005, QC09:2005, and has made two subsequent revisions, QCVN 09:2013 and QCVN 09:2017. However, in practice, this regulation is used like a voluntary standard; design review and post-construction acceptance specific to QCVN 09 are almost non-existent. Thus, Vietnam’s building energy performance can be assessed as roughly equivalent to France in 1974 – meaning that achieving carbon neutrality by 2050, as committed by the Prime Minister at the global COP 26 conference, will require a great deal of work. The important point is that if we start implementing now, we only have 30 years, compared to France, which has been implementing rigorously for nearly 60 years with a Net Zero Carbon goal for 2050. So, this is not a simple race given the current conditions.

2. GREEN BUILDING DEVELOPMENT AND CURRENT CRITERIA (REQUIREMENTS) FOR ENERGY SAVING AND EFFICIENCY

(Further analysis of the situation in Vietnam: Much discussion of green buildings, but forgetting the core issues of energy saving, efficiency, thermal balance…)

3. THE PATH TOWARDS NET-ZERO ENERGY BUILDINGS

To achieve the goal of reducing energy consumption and moving towards Zero Carbon in the construction sector, the participation of many fields is required. Science plays a key role, policy is crucial for driving change (both voluntary and mandatory), green financial incentives and tax breaks from banks and the Ministry of Finance act as catalysts, and incentives related to building density, height, and procedures from the Ministry of Natural Resources and Environment and the Ministry of Construction also play an important role in promoting energy-efficient building development.

Another very important factor frequently mentioned in international conferences is international support, both financial and technological – but we should not be overly dependent on external factors. Learning from experience and adopting technology is essential, but they will eventually leave. What is most needed is for us to receive and become self-reliant in technical skills, technology, and management to strengthen and promote internal capacity.

At this time, in my personal opinion, our biggest shortage is skilled personnel to implement energy-saving projects. The reason is that for a long time, the education system in Vietnam followed the Soviet model and did not update with knowledge from the West after the collapse of the Soviet Union. Most new calculation and design techniques updated globally since the 1970s are rarely introduced or taught in Vietnam, especially building energy use prediction calculation; the foundational knowledge in this area is zero in Vietnam. We are currently detached from the global knowledge stream in this field and desperately need to update and reintegrate.

Vietnam Prime Minister’s commitment at the global COP 26 conference: Vietnam will reduce… by 2030.

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This raises a question: why do we still have beautiful buildings and international awards, yet lack people in the field of building energy and environmental sustainability?

The answer is that, in the field of architectural design, Vietnam is doing well; beautiful, impressive works and bright spots are not uncommon… but the overall design standard is still low. A building can be beautiful and impressive, but thermal comfort, lighting, energy use, and sustainability requirements are not adequately addressed. These issues need to be solved as an integrated part of the design equation. To meet this, the role of engineers and technical personnel involved in design is very important, but this is an area we are neglecting, and we have not fully and correctly assessed the role of science, technology, and engineers in the overall design process. The consequence is that a building might be beautiful, but investment in technical systems is wasteful (over-designed just to be safe), thermal and lighting quality is low, energy consumption is high, and systems operate unreliably…

To overcome these existing problems, architects and engineers need to upgrade their knowledge with new design techniques and must use essential international design tools that have become indispensable globally to meet new demands for sustainable development, human comfort, energy saving, and investment cost optimization…

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From a policy perspective, in just the past 15 months, despite the entire country grappling with the pandemic, the government has not overlooked the push for mandatory energy efficiency for buildings.

Consecutive changes have been made through the amended Construction Law, Decree 15, Vietnam Architectural Orientation until 2030 with a vision to 2050, Circular guiding construction design costs… continuously introduced to tighten and promote energy-saving, resource-saving, environmentally friendly design, and technology application… Most notably, the new Circular guiding design costs has paved the way for additional costs dedicated to implementing Building Information Modeling (BIM), selecting energy-saving solutions, calculating fluid dynamics, obtaining environmental protection certifications, etc.

This is a positive signal that will open new doors for emerging professions, currently only nascent, to serve sustainable design. However, these could easily disappear without timely adjustments from state policies.

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The four important pillars of the real estate industry that can help us quickly catch up with the world in energy saving, sustainable development, and emission reduction commitments are: Policy, Human Resources, Investors, and Technology/Technique (materials, equipment, technology…).

Developing and promoting these four factors in parallel will contribute to guiding the real estate sector back onto its necessary path: Greener, more sustainable, and more efficient. Moving towards carbon neutrality in accordance with the government’s commitment by 2050.