Energy savings of retrofitting residential buildings with variable air volume systems across different climates

Lu, Daniel; Warsinger, David M.

doi:10.1016/j.jobe.2020.101223

Cited by 25 publications

(13 citation statements)

References 27 publications

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“…In this study, the default AHU is used for the VAV system which contains a variable speed fans. Such AHU supplies variable airflow at a constant temperature having additional precision in temperature control [72]. The VAV models in EnergyPlus have been validated by Ref.…”

Section: Vav System the Second Cooling Strategy (C02) Is Variable Airmentioning

confidence: 99%

Simulation-based framework to evaluate resistivity of cooling strategies in buildings against overheating impact of climate change

Rahif

Hamdy

Homaei

et al. 2022

Building and Environment

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Over the last decades overheating in buildings has become a major concern. The situation is expected to worsen due to the current rate of climate change. Many efforts have been made to evaluate the future thermal performance of buildings and cooling technologies. In this paper, the term "climate change overheating resistivity" of cooling strategies is defined, and the calculation method is provided. A comprehensive simulation-based framework is then introduced, enabling the evaluation of a wide range of active and passive cooling strategies. The framework is based on the Indoor Overheating Degree (IOD), Ambient Warmness Degree (AWD), and Climate Change Overheating Resistivity (CCOR) as principal indicators allowing a multi-zonal approach in the quantification of indoor overheating risk and resistivity to climate change.To test the proposed framework, two air-based cooling strategies including a Variable Refrigerant Flow (VRF) unit coupled with a Dedicated Outdoor Air System (DOAS) (C01) and a Variable Air Volume (VAV) system (C02) are compared in six different locations/climates. The case study is a shoe box model representing a double-zone office building. In general, the C01 shows higher CCOR values between 2.04 and 19.16 than the C02 in different locations. Therefore, the C01 shows superior resistivity to the overheating impact of climate change compared to C02. The maximum CCOR value of 37.46 is resulted for the C01 in Brussels, representing the most resistant case, whereas the minimum CCOR value of 9.24 is achieved for the C02 in Toronto, representing the least resistant case.

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Section: Vav System the Second Cooling Strategy (C02) Is Variable Airmentioning

confidence: 99%

Simulation-based framework to evaluate resistivity of cooling strategies in buildings against overheating impact of climate change

Rahif

Hamdy

Homaei

et al. 2022

Building and Environment

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“…In addition to the strategies discussed, there are other energy saving technologies for HVAC systems. The recent technological advancements in terms of HVAC system designs include but are not limited to the following: demand controlled ventilation systems (Cui et al , 2020); duct sealing (Harrington and Modera, 2014); logic control and FDD systems (Zhao et al , 2019); use of microchannel heat exchangers (Khan and Fartaj, 2011); variable speed drives (Schibuola et al , 2018), and variable flow volume systems (Lu and Warsinger, 2020). According to Merema et al (2018), demand controlled ventilation (DCV) system is one of the possible strategies that can be adopted to enhance the energy efficiency of the HVAC system by automatically adapting the airflow rate according to the actual ventilation demand.…”

Section: Conceptual Framework For Improving Hvac Energy Efficiency Ba...mentioning

confidence: 99%

“…In addition, Schibuola et al (2018) disclosed that the introduction of VSD technology in HVAC system has the potential in providing a global annual energy saving of 38.9% in the electric consumption of pumps and fans if compared with the same system but with constant flow rate. Lu and Warsinger (2020) posit that a multizone variable air volume (VAV) system can save energy by directing conditioned air to different occupied zones in the home as needed. VAV systems can significantly reduce source energy and energy costs due to lower fan and cooling energy usage.…”

Section: Conceptual Framework For Improving Hvac Energy Efficiency Ba...mentioning

confidence: 99%

Improving energy efficiency of HVAC systems in buildings: a review of best practices

Simpeh

Pillay

Ndihokubwayo

et al. 2021

IJBPA

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PurposeHeating, ventilation and air-conditioning (HVAC) systems account for approximately half of all energy usage in the operational phase of a building's lifecycle. The disproportionate amount of energy usage in HVAC systems against other utilities within buildings has proved a huge cause for alarm, as this practice contributes significantly to global warming and climate change. This paper reviews the status and current trends of energy consumption associated with HVAC systems with the aim of interrogating energy efficiency practices for improving HVAC systems' consumption in buildings in the context of developing countries.Design/methodology/approachThe study relied predominantly on secondary data by analysing the relevant body of literature and proposing conceptual insights regarding best practices for improving the energy efficiency of HVAC systems in buildings. The systematic review of the literature (SLR) was aided by the PRISMA guiding principle. Content analysis technique was adopted to examine germane scholarly articles and finally grouped them into themes.FindingsBased on the SLR, measures for enhancing the energy efficiency of HVAC systems in buildings were classified based on economic considerations ranging from low-cost measures such as the cost of tuning the system, installing zonal control systems, adopting building integrated greenery systems and passive solar designs to major approaches such as HVAC smart technologies for energy management which have multi-year pay-back periods. Further, it was established that practices to improve energy efficiency in buildings range from integrated greening system into buildings to HVAC system which are human-centred and controlled to meet human modalities.Practical implicationsThere is a need to incorporate these energy efficiency practices into building regulations or codes so that built environment professionals would have a framework within which to design their buildings to be energy efficient. This energy efficient solution may serve as a prerequisite for newly constructed buildings.Originality/valueTo this end, the authors develop an integrated optimization conceptual framework mimicking energy efficiency options that may complement HVAC systems operations in buildings.

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“…In the United States, VAV systems are used in more than 95% of all high-rise buildings. 5 In China, VAV systems are primarily used in high-rise buildings and large public buildings; nevertheless, they have broad application potential: the larger the building, the higher the energy saving potential of VAV systems compared to fan coil or constant air volume (CAV) systems, and the shorter the investment payback period. 6,7 As the air ducts of VAV systems are interconnected, contaminant propagation is an important consideration in system design and implementation.…”

Section: Introductionmentioning

confidence: 99%

Optimal control of critical fresh air volume based on sectional adjustment of fresh air and return air dampers

Zhao

Xing

et al. 2023

Building Services Engineering Research and Technology

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During the regulation process of VAV systems, the supply air volume changes with the real time load changes, which will cause the fresh air volume to deviate from its set value. Insufficient fresh air results in poor IAQ, whereas an excessive fresh air increases energy consumption. Therefore, an effective method to control the fresh air volume is essential for VAV systems. Based on the differential pressure control theory, two improved control methods—the fresh air section static pressure control method and the critical air volume control method—are proposed herein. Three control methods were compared through experimental study. The results indicate that differential pressure in the first improved method is higher than that in the differential pressure control method, which increases the ease of measurement. However, both these methods have approximately 15% to 25% errors when the supply air volume is small. The critical air volume control method provides more precise control of the fresh air volume, and eliminates deviations at small supply air volumes. Furthermore, the fan power is reduced as well. Investigation has demonstrated that the critical air volume control method is energy-efficient, and can provide new insights into optimized energy-saving control methods for VAV systems. This work proposed a fresh air volume control method of VAV system, the critical air volume control method. This method improves the control accuracy and the convenience of differential pressure measurement of VAV system. The reliability of the method was verified on the test rig, and it is similar to the engineering situation. Therefore, this method has practical application value. Also this method reduces the fan energy consumption of VAV system, thereby improving energy efficiency and reducing operating costs.

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Energy savings of retrofitting residential buildings with variable air volume systems across different climates

Cited by 25 publications

References 27 publications

Simulation-based framework to evaluate resistivity of cooling strategies in buildings against overheating impact of climate change

Simulation-based framework to evaluate resistivity of cooling strategies in buildings against overheating impact of climate change

Improving energy efficiency of HVAC systems in buildings: a review of best practices

Optimal control of critical fresh air volume based on sectional adjustment of fresh air and return air dampers

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