The HVAC (heating – ventilation – air conditioning) system is an extremely complex system and accounts for 50% – 70% of the total energy use of a building. Therefore, optimizing energy for the HVAC system saves the investor a lot of money in investment and operating costs.
So how to design a “no additional cost” energy-efficient building with an HVAC system? Please stay tuned for Part 3!
The reality of HVAC system design in Vietnam
The design work of the HVAC system in Vietnam now only accounts for a quick calculation of the required capacity of the system before deploying the drawings. The process of further research on the following contents does not exist when practicing design in Vietnam yet:
Further, the process of calculating heat, comfort, and building energy in Vietnam has very little feedback on the architecture to make necessary adjustments, with the primary focus on installing air conditioners to ensure cooling. There is no overload or underload check like when applying simulator operation that simulates the real condition.
Cooling efficiency calculation for arranging VRF/VRV outdoor units
Insufficient in-depth research on the HVAC system, or simply a quick calculation of the system, will cause excess capacity, thermal inconvenience, and wasted energy, causing the space to be too hot or too cold. Users will feel uncomfortable as a result. One wants to lower the temperature, the other wants to increase it, but they still have to pay an unworthy large energy cost.
Hence, the design of a building HVAC system, including trying to reduce the air-conditioning capacity, is essential to the energy-saving design process (as outlined in the ASHRAE 209 integrated design process).
This requires the engineering team to consider at the same time other factors such as building volume, lighting, ventilation, glazing material, enclosure material, heat recovery, machine selection, mode of operation, etc., because those are the factors that affect the decision-making on the size of the HVAC system and directly affect the operation of the entire building.
Example of Energy Saving HVAC System Design
Checking temperature distribution in a hotel room
Whole year load diagram of a building used as a laboratory and office. This diagram is very important in central cooling system design, district cooling system design.
The installation of heat recovery equipment in Vietnam’s climate also needs careful consideration, because the difference in temperature inside and outside the house is not large.
The graph above depicts a comparison between with and without heat recovery at a large hotel in the central region, with the most operating characteristics from evening to morning (a pleasant outdoor temperature and humidity). So through calculating for the whole year, it is shown that the heat recovery installation (red) uses more energy than the no heat recovery option (blue).
Considering each month, only the hot months of 5, 6, 7, and 8, the option with heat recovery can bring about energy-saving efficiency. This simulation result only applies to 01 hotel with a defined operating schedule and chiller control method. Another project, even in the same central region, may have completely different simulation results.
HVAC Design in Vietnam & Solutions
In general, the popular design consultants in Vietnam only design to the equipment capacity and then deploy the drawings, the design here is considered completed.
There are still many unanswered questions about design, investment efficiency, and many other factors affecting energy use that have not been paid attention to. This reduces service quality, a living comfort, and increases energy use while still wasting investment costs in unnecessary ways, such as:
The above questions will all be clarified by data and economic efficiency through the application of professional energy simulation to thoroughly address the concerns about the project, the efficiency of capital use, operating costs, and quality of life.
Tran Thanh Vu – Edeec Founder & Energy Efficient Building Design Expert
Vietnam’s leading Energy Efficiency Building Design Consultant
EDEEC is the leading energy-saving design consulting company in Vietnam with a team of experts for more than 10 years trusted by prestigious international organizations such as UNDP, IFC – World Bank, VCEP – USAID, etc.
EDEEC pioneered the application of technology Building Energy Simulation and Energy Integrated Design technology to “solve the problem” to reduce building energy consumption, especially to REDUCE investment costs and reduce operating costs for buildings. The project is designed to maximize profits for the investor right from the first design stage while still ensuring the highest living comfort for users.
Click here to get your project consulted by expert Tran Thanh Vu.
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