Energy Efficiency and Thermal Comfort: Core Foundations for Green Buildings in Vietnam

ENERGY EFFICIENCY AND THERMAL COMFORT – CORE ISSUES IN GREEN BUILDING DEVELOPMENT

M.Arch. Tran Thanh Vu - Edeec & ISSER

In developed countries, the issue of energy efficiency, related to energy security, was recognized very early on. They proactively introduced mandatory laws and design regulations to ensure efficient energy use through Codes and Standards. These requirements are mandatory when submitting building permit applications. Later, the trend of voluntary green building certifications emerged. However, the core requirement of complying with minimum energy requirements has been integrated into green rating systems. Therefore, saving energy and complying with codes remain mandatory, while achieving green certification is voluntary. In this paper, we focus on clarifying the issue: For green building development, the core issues must be energy efficiency and thermal comfort.

ENERGY EFFICIENCY – VIETNAM AND INTERNATIONAL CONTEXT

For several decades now, the Vietnamese government has shown increasing interest in energy efficiency nationwide. Although there have been positive changes, the overall energy efficiency of the economy remains low compared to neighboring countries. To generate 1 USD of GDP, we use energy more than 2.5 times 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 increase competitiveness and overall economic efficiency.

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

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

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

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Later, the voluntary trend of green buildings emerged, but the core requirement of complying with minimum energy requirements has been integrated into green rating systems. Therefore, saving energy and complying with codes remain mandatory, while achieving green certification is voluntary. Simply put, green certification systems reference other industry standards and codes, especially requirements for HVAC (heating, ventilation, air conditioning), thermal comfort, lighting, energy, etc. Green buildings will require compliance with these requirements in the form of: You must exceed the minimum requirements by 3-10% as a prerequisite (failure to meet this means failing the certification and not needing to consider other criteria).

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Lotus Certification – Based on a predictive energy simulation model compliant with QCVN 09:2017 minimum level.

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The point system for LEED is more complex than Lotus; points depend on the building type, and additional points are pre-set. The reference standard is ASHRAE 90.1.

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In France, energy efficiency for buildings was first addressed after 1973, following the oil crisis. Currently, thermal and energy regulations are continuously updated and gradually tightened according to advancements in materials, technology, and equipment, with the goal of moving towards positive energy buildings. This means that the total energy produced by the building over a weather cycle (1 year) is greater than the energy it consumes. To achieve this, France’s building energy regulations (RT – Règlement thermique) have been continuously updated through many versions, the latest being RT 2020 – BEPOS - Batiment à énergie positive.

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For comparison, Vietnam has had energy efficiency regulations since 2005, QCVN 09:2005, which has been revised twice to date: QCVN 09:2013 and QCVN 09:2017. However, in practice, this code is used as a voluntary standard; verification of design documents and post-construction acceptance specifically for QCVN 09 is almost non-existent. Thus, building energy performance in Vietnam is arguably equivalent to France in 1974 – which means that achieving carbon neutrality by 2050, as committed by the Prime Minister at COP 26, will require a great deal of work. The important thing is that if we start now, we only have 30 years, compared to France, which has been rigorously implementing policies for nearly 60 years with a Net Zero Carbon target for 2050. Therefore, this is not a simple race given the current conditions.

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

(Additional analysis content: Current situation in Vietnam: Much talk about green buildings but neglecting the core issues of energy saving, efficiency, thermal balance…)

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3. THE PATH TO NET-ZERO ENERGY BUILDINGS

To achieve the goal of reducing energy use and moving towards Zero Carbon in the construction sector, the participation of many fields is needed, with science playing a key role, policy being a decisive factor for promotion (both voluntary and mandatory), green financial incentives, tax and fee incentives from banks and the Ministry of Finance acting as catalysts, and incentives for building density, height, and procedures from the Ministry of Natural Resources and Environment and the Ministry of Construction also playing an important role in promoting the development of energy-efficient buildings.

Another very important factor, always mentioned in international conferences, is international support, both financial and technological – but we should not rely too much on external factors. Learning from experience and adopting technology is very necessary, but they come and go. The most crucial thing is for us to absorb and become self-sufficient in technology, engineering, and management to strengthen and leverage our internal capabilities.

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At this time, in my personal opinion, our greatest lack is the human resources to implement energy-saving projects. The reason is that for a long time, the training system in Vietnam followed the Soviet trend and did not update knowledge from the West after the dissolution of the Soviet Union. Most of the new calculation and design techniques updated globally since the 1970s have been rarely introduced or taught in Vietnam, especially building energy performance simulation; foundational knowledge in this area is zero in Vietnam. We are currently disconnected from the global knowledge flow in this field and urgently need to update and reintegrate.

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Commitment of the Prime Minister of Vietnam 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, still win international awards, but 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, with many beautiful, impressive works and bright spots emerging… but the overall level of design is still low. A building may be beautiful and impressive, but thermal comfort, lighting, energy use, and sustainable development requirements are not adequately addressed. These aspects need to be solved in the overall design equation. To meet this, the role of engineers and technical staff participating in the design is very important, but this is an area we are neglecting, as well as not fully and correctly assessing the role of science, technology, and engineers in the overall design process. The consequence is that the building may be beautiful but with wasteful investment in technical systems (over-specified for safety), low thermal and lighting quality, high energy consumption, unreliable systems, etc.

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To overcome existing problems, the skills of architects and engineers need to be upgraded with new design knowledge. They need to know how to use design tools that have become indispensable globally to meet the new demands for sustainable development, human comfort, energy saving, optimal investment costs, etc.

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From a policy perspective, in just the past 15 months, despite the whole country fighting the pandemic, the Government has not neglected to promote the mandatory nature of energy efficiency for buildings.

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Consecutive revisions to the Construction Law, Decree 15, Architectural Orientation of Vietnam to 2030 with a vision to 2050, Circular guiding building design costs… have been continuously issued to tighten and promote energy-saving design, resource-saving, environmental friendliness, technology application… Most notably, the new Circular guiding design costs has paved the way for additional costs allocated to implementing Building Information Modeling (BIM), selecting energy-saving solutions, fluid dynamics analysis, environmental certification…

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This is a welcome sign that will open new doors for emerging professions serving sustainable design, which could easily disappear without timely adjustments from state policy.

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The four important pillars for the real estate sector to quickly catch up with the world in energy saving, sustainable development, and ensuring emission reduction commitments are: Policy, People, Investors, and Technology (materials, equipment, technology…).

Developing and promoting these four factors concurrently will help the real estate sector return to its necessary path: greener, more sustainable, and more efficient. Moving towards Carbon Neutrality in accordance with the government’s commitment by 2050.