Summary of passive strategy
Passive strategy is to regulate dwelling conditions by utilizing solar
energy, wind, temperature and humidity in nature environment without
mechanical equipment consuming conventional energy. Buildings applying
passive strategy accrete with peripheral circumstance other than
isolated from surroundings. This essay summarizes common passive
strategies and their application in Chinese traditional buildings.
Passive design strategies could be classified into building layout
,envelope thermophysics, and building geometry according to different
green building rating tools such as BREEAM, LEED, CASBEE and
GBL-ASGB.[11[] Chen,
Xi, H. Yang, and L. Lu. ”A comprehensive review on passive design
approaches in green building rating tools.” Renewable &
Sustainable Energy Reviews 50(2015):1425-1436.]
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Building layout design takes account of peripheral obstructions and
any other relevant external circumstance to determine the building
shape and orientation. Based on self-shading effect and reflectance,
building layout influences daylight availability, solar gain,
ventilation and thermal performance. It is a vital strategy especially
when the location has a high density
circumstances.[22[]
Li, D. H. W., et al. ”A study of the daylighting performance and
energy use in heavily obstructed residential buildings via computer
simulation techniques.” Energy &
Buildings 38.11(2006):1343-1348.]
Typical passive strategies:
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Transitional space
Transitional space is generally used in residence in northern China.
Winter in northern China is frosty and severe. To resist the coldness,
a transitional room is set between the outside and habitable room in
the north of the residence as kitchen or storeroom.(Fig.1)
Fig. 1 Traditional residence in Zhaodong
City[33[]
Chen.Z, Zhang.SM . ”The Passive Techniques in Chinese Traditional
dwellings.” Huazhong Architecture 26.12(2008):204-209.]
①
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Direct/ Indirect solar gain
Related parameters of solar gain are the construction’s shape and
layout, building’s orientation, window’s shape, size, orientation
(daylighting) and so on.[44[]
Lotfabadi, Pooya. ”Analyzing passive solar strategies in the case of
high-rise building.” Renewable & Sustainable Energy
Reviews52(2015):1340-1353.]
Since sunlit is a measure to determine the radiation interception,
which regulates temperature inside the
buildings,[55[]
Ralegaonkar, Rahul V., and R. Gupta. ”Review of intelligent building
construction: A passive solar architecture
approach.” Renewable & Sustainable Energy
Reviews 14.8(2010):2238-2242.] one-storey
houses constitute most of the residence in northern China to avoid
blocking. And the aspect ratio of courtyard is high to gain solar
energy at high latitudes. [66[]
Tang, Luan.JY, and Liu. ”Discusssion on energy-saving technologies
of traditional courtyard dwellings in Northern
Henan.” Architecture Scilence28.6(2012):10-13.](Fig.2)
Fig. 2 Traditional residence in Beijing ②
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Ventilation&Shadings
Residence of Hong Village is elaborately planed considering the high
density and the scorching climate. A lake is located to the south of
the village as a main entrance and the lanes converge at the wide open
lake area. (Fig.3)When the wind in summer flows from the open area to
narrow path, the wind pressure strengthens to take the heat
away.[3](Fig.4)
Fig. 3 Residence of Hong Village ③
Fig. 4 Lanes in Hong Village ③
Another case of residence utilizing nature wind is Pile dwelling of
Hmong. The dwelling is suspended up to ventilate better.
[77[] Hu, Liang, and
Chen. ” Energy saving value research of Pile dwelling-Case stugy of
retrofitting of Leyuan.” 2013 Annual meeting of Chinese urban
planning 2013.](Fig.5) A similar solution is
used in dwelling in Nanjing
.[88[]
Min.Z. ”Study on ventilation design of Chinese traditional
dwellings:Cases study of Nanjing old streets.” Urban development
research 22.12(2015).] The floor is staked
30-40cm, so the air could flow under the dwelling from exhaust holes on
the footing of the walls by the wind system crossing the village.
(Fig.6)
Besides the wind pressure ventilation, thermal pressure ventilation is
widely used. Small yard in the centre is slim covered with eaves which
reduce solar radiant heat. By means of thermal pressure, air flows from
high temperature surrounding to the small
yard.[8](Fig.7)