Page 57 - JCAU-5-2

Journal of Chinese
Architecture and Urbanism Cooling energy-saving mechanism

human thermal comfort in different climate zones, and where people feel the thermal comfort, and an appropriate
the user requirements of different functional rooms, and increase or decrease of temperature within this range
the energy-saving effect can be achieved at different levels will not significantly affect people’s thermal sensation
in different cities. In cities with a hot climate, the annual (Ghahramani et al., 2014; Belazi et al., 2019). The above
average relative energy-saving effect is 3.2%, and in cities research shows that adjusting the temperature set-point
with a cold climate, it is 1.6%. The hotter the region, the is an important behavioral energy-saving measure that
greater the energy-saving potential of adjusting the setting attracts wide attention from scholars around the world,
temperature of the air conditioner. However, due to the and many research results are emerging. However,
large number of cities selected by the author, and the lack China lacks a global perspective in the research field of
of a unified standard for adjusting the set-point based on building energy conservation, so more attention should
different climatic characteristics, the energy-saving effects be paid to temperature set-points and their energy-saving
in different cities after adjusting the set-point are too mechanisms. Therefore, this paper will focus on the energy-
complex to compare, and it is difficult to deeply analyze saving effect of raising the temperature set-point of air-
the energy-saving mechanisms of different set-points. conditioning in hot areas of China and study the behavioral
Moreover, the authors only give the research results of the energy-saving potential through a quantitative analysis
relative energy saving rate but it lacks the research on the method. In addition, the building envelope is a major
absolute energy-saving effect. Hoyt et al. (2015) believed focus of passive building energy conservation research.
that the temperature set-point adjustment range of HVAC The thermal performance of the building envelope can
systems equipped with office buildings in the US was too significantly affect the energy consumption of the building.
narrow, and there was a lack of quantitative research on At present, there is abundant research on the energy-
the energy-saving effect of widening the range. Thus, the saving characteristics of the building envelope. Feng
authors applied the widening of the system’s temperature et al. (2010) simulated and calculated the air-conditioning
set-point range to office building models in seven US cities cooling and heat load of office buildings with different
with different climate; the original narrow set temperature heat transfer coefficients at the same temperature set-point
range of air-conditioning (21.1°C – 22.2°C) was used as the through DeST software and found that the energy-saving
comparison baseline, and the building energy consumption effect of different envelope thermal characteristics was
under different ranges was simulated by Energy Plus significantly distinctive in different seasons. Natephra et al.
software. The results showed that widening the set-point (2018) established an office building model on the building
range has a significant energy-saving effect. For example, information modeling (BIM) platform and studied the
increasing the set-point of the air conditioner from 22.2°C automatic evaluation method of energy-saving building
to 25°C will achieve a 27% energy-saving rate for the design based on BIM data by changing the information of
equipment system. In addition, the authors compared the the building envelope. The results showed that the thermal
energy-saving effects after adjusting the temperature set- characteristics of the envelope structure had a significant
point in cities with different climates and concluded that impact on maintaining an indoor thermal environment
increasing the setting temperature of air conditioning in and realizing the high energy efficiency of the building.
hotter climate zones can obtain more significant energy- Scholars all over the world regard envelope performance
saving effects, which proves that adjusting the set-point of as an important factor affecting energy consumption and
an air-conditioning system has a great impact on reducing energy savings when studying the existing building’s energy
energy consumption. However, the authors did not explore conservation retrofit and discussing how to improve the
the energy-saving mechanism of adjusting the temperature envelope of the building.
set-point under the same climatic condition. For the same Existing buildings are built at different stages of social
building type in the same city, the energy-saving effect, development, and the construction level is varied at
and the mechanism behind adjusting the temperature set- different stages, which makes the performance of existing
point, should be further studied. buildings’ envelopes different. When the energy-saving
As for the doubt that adjusting the settings in measure of adjusting the temperature set-point of the air
temperature will reduce occupants’ thermal comfort, some conditioner is applied to existing buildings, the influence
scholars have carried out relevant research and proved that of various envelope performances on the energy-saving
the environmental conditions for people’s thermal comfort effect must be considered (Liao et al., 2022). To study
are not fixed. Through field surveys, questionnaires, the energy-saving effect of existing buildings in the US at
physical metrology, simulation of a thermal comfort different HVAC temperature set-points, Ghahramani et al.
model, and other methods, a certain range of temperatures (2016)adopted the reference office building model of three

can be obtained based on the environmental conditions sizes given by the US DOE standard. Each model is divided

Volume 5 Issue 2 (2023) 3 https://doi.org/10.36922/jcau.0877