Earth coupling

Earth coupling uses the moderate and consistent temperature of the soil to act as a heat sink to cool a building through conduction. This passive cooling strategy is most effective when earth temperatures are cooler than ambient air temperature, such as hot climates.

Direct coupling - Direct coupling, or earth sheltering, occurs when a building uses earth as a buffer for the walls. The earth is an endless heat sink and can effectively mitigate temperature extremes. Earth sheltering improves the performance of building envelope assemblies by reducing the magnitude of conductive and convective heat loss and gains by reducing infiltration.[13]

Indirect coupling. A building can be indirectly coupled with the earth by means of earth ducts. An earth duct is a buried tube that acts as avenue for supply air to travel through before entering the building. Supply air is cooled by way of conductive heat transfer between the concrete tubes and soil. Therefore, earth ducts will not perform well as a source of cooling unless the soil temperature is lower than the desired room air temperature.[13] Earth ducts typically require long tubes to cool the supply air to an appropriate temperature before entering the building. A fan is required to draw the cool air from the earth duct into the building. Some of the factors that effect the performance of an earth duct are: duct length, number of bends, thickness of duct, depth of duct, diameter of the duct, and air velocity.

Ventilation

Ventilation as a natural cooling strategy uses the physical properties of air to remove heat or provide cooling to occupants. In select cases, ventilation can be used to cool the building structure, which subsequently may serve as a heat sink.

Cross ventilation - The strategy of cross ventilation relies on wind to pass through the building for the purpose of cooling the occupants. Cross ventilation requires openings on

two sides of the space, called the inlet and outlet. The sizing and placement of the ventilation inlets and outlets will determine the direction and velocity of cross ventilation through the building. Generally, an equal (or greater) area of outlet openings must also be provided to provide adequate cross ventilation.[9]

Stack ventilation - Cross ventilation is an effective cooling strategy, however, wind is an unreliable resource. Stack ventilation is an alternative design strategy that relies on the buoyancy of warm air to rise and exit through openings located at ceiling height. Cooler outside area replaces the rising warm air through carefully designed inlets placed near the floor.

Night flush cooling The building structure acts as a sink through the day and absorbs internal heat gains and solar radiation. Heat can be dissipated from the structure by convective heat loss by allowing cooler air to pass through the building at night. The flow of outdoor air can be induced naturally or mechanically. The next day, the building will perform as a heat sink, maintaining indoor temperatures below the outdoor temperature. This strategy is most effective in climates with a large diurnal swing so the typical maximum indoor temperature is below the outdoor maximum temperature during the hottest months.[10] Thermal mass is a necessary component to dissipate heat at night.

Bordeaux Law Courts

The design concept involved liberating the court-rooms from the box. The timber-clad solution employs a mix of high technology, computer-controlled machinery and traditional craftsmanship.

www.rsh-p.com / 2010

Bordeaux Law Courts

Place/DateBordeaux, France 19921998ClientTribunal de Grande InstanceCost27 millionGross Internal Area25,000m

ArchitectRichard Rogers PartnershipStructural EngineerOve Arup & Partners/OtH Sud-OuestServices EngineerOtH Sud-Ouest/Ove Arup & PartnersQuantity SurveyorInterfaces, IngropAcoustic ConsultantSound Research Laboratories Cladding ConsultantRice Francis Ritchie

Landscape ArchitectDan Kiley/Edward Hutchison/Branch AssociatesLighting ConsultantLighting Design PartnershipMain ContractorSpie Citra Midi AtlantiqueSite ManagementOtH Sud-Ouest

Richard Rogers Partnership (RRP) the international competition to design new law courts for the historic city of Bordeaux in 1992. The design was for a building that would, through a feeling of transparency and openness, create a positive perception of the accessibility of the French judicial system. The brief was complex, requiring complete separation of public and judicial circulation. By pulling the building into its constituent parts, the resulting transparency encourages a sense of orientation, rendering an historically imposing institution more accessible. Key elements of the design include the creation of public space and integration with

the existing urban landscape. Public entry to the building is via a flight of stairs placed to the side, leading to the Salle des Pas Perdus at the core of the building, where lawyers, their clients and the public meet. The seven courtroom pods are clad in cedar, raised on pilotis above the limestone plinth within a great glass curtain wall under an undulating copper roof. The administrative offices are reached by bridges spanning the atrium the clarity of the plan ensuring that different secure routes across the atrium are maintained both for the public and for magistrates. With its use of irregular forms and natural materials, the building successfully complements its sensitive

environs, including a section of the citys medieval wall. A strong emphasis is placed on effective passive control systems. The pods are shaded beneath the great roof and manually-operated brise-soleil windows along the western faade reduce solar gain. The flask-like volumes allow daylight deep into the court rooms and, through their height, ensure temperature control through stratification. The glazed box wrapping around the chambers, with its sun-screening and ventilation systems incorporated within the roof, functions as a breathing container. In addition, the podium and offices are built in concrete a very effective passive heat control system.

Radiative cooling

All objects constantly emit and absorb radiant energy. An object will cool by radiation if the net flow is outward, which is the case during the night. At night, the long-wave radiation from the clear sky is less than the long-wave infrared radiation emitted from a building, thus there is a net flow to the sky. Since the roof provides the greatest surface visible to the night sky, designing the roof to act as a radiator is an effective strategy. There are two types of radiative cooling strategies that utilize the roof surface: direct and indirect.[8]

Direct radiant cooling - In a building designed to optimize direct radiation cooling, the building roof acts as a heat sink to absorb the daily internal loads. The roof acts as the best heat sink because it is the greatest surface exposed to the night sky. Radiate heat transfer with the night sky will remove heat from the building roof, thus cooling the building structure. Roof ponds are an example of this strategy. The roof pond design became popular with the development of the Sky thermal system designed by Harold Hay in 1977. There are various designs and configurations for the roof pond system but the concept is the same for all designs. The roof uses water, either plastic bags filled with water or an open pond, as the heat sink while a system of movable insulation panels regulate the mode of heating or cooling. During daytime in the summer, the water on the roof is protected from the solar radiation and ambient air temperature by movable insulation, which allows it to serve as a heat sink and absorb, though the ceiling, the heat generated inside. At night, the panels are retracted to allow nocturnal radiation between

the roof pond and the night sky, thus removing the stored heat from the days internal loads. In winter, the process is reversed so that the roof pond is allowed to absorb solar radiation during the day and release it during the night into the space below.[4]

Indirect radiant cooling - A heat transfer fluid removes heat from the building structure through radiate heat transfer with the night sky. A common design for this strategy involves a plenum between the building roof and the radiator surface. Air is drawn into the building through the plenum, cooled from the radiator, and cools the mass of the building structure. During the day, the building mass acts as a heat sink.

Evaporative cooling

Evaporative cooling. The design relies on the evaporative process of water to cool the incoming air while simultaneously increasing the relative humidity. A saturated filter is placed at the supply inlet so the natural process of evaporation can cool the supply air. Apart from the energy to drive the fans, water is the only other resource required to provide conditioning to indoor spaces. The effectiveness of evaporative cooling is largely dependent on the humidity of the outside air; dryer air produces more cooling. A study of field performance results in Kuwait revealed that power requirements for an evaporative cooler are approximately 75% less than the power requirements for a conventional packaged unit air-conditioner.[11] As for interior comfort, a study found that evaporative cooling reduced inside air temperature by 9.6C compared to outdoor temperature.

Kejia House

Plants. EXPO in Shanghai, France pavilion

Natural

Plants. Creepers on the wall.

Housing Style in Xinjiang, China.

Housing Style in northwest part of China.

The Poor in Ancient Romas courtyard.

Painting.

Earth couplingRSHP_A_JS_1990_L_E_GBEarth coupling