In dense mega cities, high-rise buildings energy consumption on mechanical ventilation and overheat produced by the air conditioners are among big problems for the sustainable building development and green city construction. Solar chimney is proved to be an efficient method to promote natural ventilation for buildings. Different types of solar chimney are discussed with different high-rise building layout and floorplans. Solar chimney geometry and environment basic data can be evaluated to optimize its natural ventilation.
In hot and humid areas, people depend heavily on electricity-powered air conditioners to provide comfortable indoor temperature. The demand of electricity for air conditioning in dense cities in summer counts a big part for the building consumed energy and the heat generated by the air conditioners conversely make the city heat island effect more severe. In developed countries, the buildings sector is the final user of the biggest energy amount (35-45%) and more than half of that energy is due to thermal conditioning . To meet the rise in electricity, demand more amount of fossil fuel needs to be burnt, which then increases its environmental footprint as well. Solar chimney (SC) is found as one of the efficient methods to heat and ventilate indoor air in the hot and humid areas as well as cold climate countries. It has attracted attention in recent years because of its ability to effectively drive natural ventilation. The main mechanism is like this: air enters the chimney at its lower level from the premises which are to be ventilated; solar radiation is absorbed by the main body of the chimney with high thermal storage opaque materials on surfaces or on inner wall with glass surfaces; the absorbed solar radiation then increases the air inside the chimney; as the air is heated, its density decreases, generating a natural ascending flow; when the air reaches the open top of the chimney then is evacuated outside . There are currently many papers discussing SC in order to reduce the indoor temperatures using natural ventilation. As a reliable renewable energy system, SC has been largely utilized to conquer global energy crisis . Maerefat & Haghighi  proposed a system that employed a SC along with an evaporative cooling cavity to cool the air, that was able to reduce room temperatures
by 4-9 °C from the ambient. However, the humidity of the indoor air, increased to levels higher than ASHRAE recommended value of 65% relative humidity for occupied indoor spaces . Due to the natural ventilation, a building in Japan with SC was found to reduce the fan shaft power requirement by about 50% in annual total, even up to 90% in January and February . Inspired with the prototype of SC power plant built in Manzanares, Spain, a new type of building-integrated SC is introduced . There a 11-story building was designed to integrate three types of SC: outside-wall SC, elevator shaft SC and atrium SC. The outside-wall SC which benefits from the neighboring staircase as an additional radiation collector and chimney, can run much better than the separated wall SC. Also, to make the SC function more effectively, every atrium space for different floors is connected as a whole, so all the small atria can better benefit from the SC ventilation effect.
Generally, many of the researchers on SC adopted physical experiments to evaluate the ventilation effect. Cheng et al.  introduced a SC platform with a dimension of 1.5 m × 1.5 m × 0.9 m to evaluate natural ventilation and smoke exhaustion, considering four influencing factors, including height of cavity inlet from the floor, cavity depth, solar radiation and fire size. Results show that external radiation shows obvious benefit on enhancing natural ventilation, while its influence on smoke exhaustion is limited. Ahmed and Hussein  made a hybrid SC with PV panels (348 cm*67cm*10cm) and studied two types of SC with different cover and absorber materials. The two types of SC are similar as show in while the thermal storage material is changed by PV panels. It is found that the system A (collector glass roof and a PV panel as an absorber) had higher thermal
gain than system B (PV panel as collector roof cover and plywood
as a base absorber) while the daily average of electrical power in
system B was a little higher (6%). Zha et al.  have studied a SC
of 6.2m length, 2.8m width and 0.35m air gap, the experimental
results show that air flow rate of 70.6 m3/h ~1887.6 m3/h can
be achieved during the daytime in the testing day. Results show
that during the transition seasons (from April to October), SC
can be used for saving energy with an energy saving rate around
14.5% in Shanghai. Some other researchers [11-13] investigated
the thermal behavior of a SC with Phase Change Material (PCM).
Ayadi et al.  have adopted the code Ansys-Fluent 17.0 to study
different impact of five turbulence models on the distribution of
the air flow characteristics. The work showed that the turbulence
model types affect directly the numerical results. Asadi et al.
 used Energy Plus software to simulate the performance of
SC in different parts of a typical seven-story office building and
studied the influence of the layout of SC. Neves and Silva 
have studied a SC with wind tunnel experiments and computer
simulations using Energy Plus. Results showed that the airflow
rate and distribution pattern at the outlet openings of the SC are
influenced by either the thermal gradients and, mainly, by the
outdoor wind velocity and direction. Ghanbari and Rezazadeh
 have applied a novel application of a giant chimney with the
practical purpose of helping to ventilate and decrease the local
air pollution in metropolises. Results show that a chimney with
high altitude, working in low ambient temperature and unstable
weather conditions, and in expanded cities near sea level will
typically produce better performance.
Overall, most of the existing literature studied SC on its
geometry, layout and outdoor environment (such as temperature,
wind velocity and direction), based on a small-scale model (even
a case model with 2 story high) or a numerical model. However,
examples of high-rise building with SC are hardly found. As we
know, high-rise buildings with their vast facades have a great
potential to consume sustainable energies and therefore they
can easily gain solar radiations. There are many famous buildings
that are well designed to utilise solar radiation to promote
natural ventilation, for example, the Frankfurt Commerzbank
Tower and the Pinnacle Tower, which are separately analysed on
the solar design aspects . For many high-rise buildings in the
metropolises, the vast facades can act as a great solar radiation
gainer, which would be much potential to integrate SC.
On the other side, the materials for radiation absorber for
the SC need to be selected. Most researchers use simple blackpainting
concrete wall [16,19], dark porous materials  as
heat-absorbing materials, while some others adopt PV panel
. In fact, micro-algae integrated panel can be a good choice.
Cervera & Pioz  has introduced the micro-algae integrated
panel for building envelop (window, wall and roof). Microalgae
photo-bioreactor has advantages such as energy storage,
Co2 absorber, sugar, protein and oxygen producer, etc . In
building integrated SC design, vast of facade and roof area can be
used for this algae photo-bioreactor panels as the envelop glass
and solar radiation absorber.
With consideration of other experiments results in the
literature, wind flow in the buildings integrated SC may not strong
enough to generate electricity, but efficient natural ventilation is
generally obvious, especially for high-rise buildings as they offer
higher air-pressure variance and bigger solar radiation receiver
surface. Three types of SC, namely outside-wall SC, elevator shaft
SC and atrium SC, can be integrated with high-rise buildings. For
better promoting and evaluating natural ventilation in high-rise
buildings, parametric study with CFD simulation and physical
experiments are proposed.
Wang B, Adolphe L, Léa D COT (2014) New building typology for solar chimney electricity. In: Cavallo R, Komossa S, Marzot N, Pont MB, Kuijper J (Eds), New urban configurations. IOS Press: Amsterdam p: 293-298.
Zha XY, Zhang J, Qin MH (2017) Experimental and Numerical Studies of Solar Chimney for Ventilation in Low Energy Buildings. 10th International Symposium on Heating, Ventilation and Air Conditioning, ISHVAC2017, Jinan, China Procedia Engineering 205: 1612-1619.
Ayadi A, Nasraoui H, Bouabidi A, Driss Z, Bsisa M et al. (2018) Effect of the turbulence model on the simulation of the air flow in a solar chimney. International Journal of Thermal Sciences 130: 423-434.
Cervera R, Pioz J (2015) Architectural Bio-Photo Reactors: Harvesting Microalgae on the Surface of Architecture, en Pacheco Torgal et al.(ed.), Biotechnologies and Biomimetics for Civil Engineering, New York.