This study presents the challenge of the integrated problem of sustainable cooling. It describes a dynamic environment in the specific context of Vietnam, where there are many opportunities for the transition to renewable energy: while solar (PV) and wind energy have a wide range of potential in green energy procurement, there are still challenges in the transmission and distribution of energy. The urban environment poses additional challenges: city-specific impacts, such as urban heat islands and radiation, urban air pollution, and the closure of surfaces, increasing the need for cooling. At the same time, many modern buildings are not well suited to reducing the need for cooling, and high levels of pollution make it difficult for citizens to use "free cooling". This already difficult starting position can generate negative momentum of its own: the building's poor thermal performance increases the need for active cooling while ensuring worse initial conditions, for example, if the electricity for the air conditioning system is generated by fossil fuels.
The study proposes a multi-stage process to move towards more sustainable cooling. After assessing Vietnam's renewable energy cooling environment, it hopes to green the cooling process, first by analyzing the potential for renewable energy integration. The issue of reducing active cooling was then discussed. To find out the most important parameters, we created a simulation for each of the two building types in the focus cities of this study, Ho Chi Minh City (HCMC) and Hanoi. The most important outcome is that passive measures, especially large-scale construction, shading, window-to-wall ratio (WWR) and building orientation, have a large impact on the number of temperature hours that are acceptable at room temperature. In addition, the evaluation of cooling technologies focuses on economic feasibility and viability in urban environments. Compiled by Chen Jiaoyun
The results show that solar PV installations are considered to be the most viable solution for cooling needs. As there is currently no operational feed-in tariff (FIT), any renewable energy installation would only need to cover the base load set by the building, requiring the potential for future expansions. The results further suggest that mechanized nocturnal ventilation is a more important improvement factor. In theory, the installation and proper maintenance of mechanical ventilation filters can improve air quality. However, smaller decentralized ventilation systems in particular require regular and ongoing maintenance.
To sum up, the ideas they put forward were inspired by the local theme, adding the potential for energy savings and thermal comfort, and they tried to get as close as possible to the reality of Vietnam. The study proposes different decision trees to develop projects and decisions to improve the sustainability of cooling, which can be found in the last section. While this study only assesses the local situation in Vietnam, it can also provide a reference for the rest of the world.
