Taiwan is an island in the South East Asia on the Pacific Rim at a latitude of 23 to 24 degree north, which sits right on the Tropic of Cancer. Taipei City is at the north tip of the island and its latitude is 24 degree north. The sub-tropical climate brings high humidity to Taipei’s long hot summer and short cold winter.
The high temperatures coupled with the high humidity make summers in Taiwan very uncomfortable.
Our summer extends from early May to late September. Winter and spring are the raining seasons here. Autumn months are pleasant with the right temperatures and slightly high humidity. However, the comfortable spring and autumn are very short. March and April are the spring months while Octo-ber and NovemOcto-ber are the autumn months.
The passive design strategies for Taiwan’s hot and humid summer are somewhat complicated. The ma-jor strategy is to provide shading while increasing ventilation. Shading will cut down the heat gain from the solar radiation. Ventilation is to reduce humidity by lifting moisture from the air. It also increases thermal comfort through evaporative heat loss.
The cold and humid winter also presents a design challenge. The design strategy is to increase indoor temperatures with solar radiation. Preventing heat loss is another strategy for winter comfort. Adding proper insulation materials may reduce heat loss in winter.
For the Solar Decathlon 2014 prototype, we included the following 4 passive strategies to further con-serve the energy:
Vegetation Cooling Diagram 1. Thermal Mass
2. Water wall 3. Green core 4. Smart skin
1. Thermal mass
1 To 1 Prototype Of Water Thermal Mass
A 30cm water thermal wall is built on the west side of the house. The thermal wall is constructed with recycled Polyethyl-ene Terephthalate Polymer bottles – the Polli-Bricks. Each bottle contains 6 litter of water. The bottles are piled up to 2 me-ter height-wise and 3 meme-ter length-wise.
The bottles are held together and fixated to a transparent acrylic sheet on their ex-terior side. The water in the thermal wall absorbs solar radiation during the day and releases heat to interior space at night.
The air space between the bottles and the acrylic sheet remains heated during day time through the green house effect and it also prevents radiant heat loss at night.
In Taipei, the acrylic sheet has openings on both the upper and lower ends. These openings allow air circulation in the sum-mer heat and that will reduce overheating in summer. As a result, the wall will receive solar radiation during the day, and allow heat loss to the outdoor at night. A three day experiment showed the thermal wall could keep the indoor temperature con-stant even when the outdoor temperature fluctuates drastically.
WEST
Polli-Bricks Filled With Water
Thermometer
Making Of Testing Model Section Detail Of Thermal Maee
Polli-Bricks temperature records 2013/10/07-09
2. Water Wall
Inspired by the agricultural technology of orchid greenhouse, the NCTU/UNICODE team designed a water wall in the inlet side window of the Orchid House. On the mezzanine level of Orchid House prototype, a water wall is installed and will be turned on when the temperature between the double skin rises above 27 degrees Celsius. Together with the water wall, a row of fans on the ceiling will create an air draft and draws hot air out and create the chimney effect.
Diagram 2.3.3: Air flow within the semi-public area
The purpose of the water wall is to lower the out-door air temperature before it enters the house.
When the outdoor temperature is above the com-fortable level, the water wall near the south end of the house would come on automatically. The out-door air will then be drawn into the terrace space by the fans near the ridge of the roof. In order to adjust to the high humidity in Taipei’s summer, the water in the water wall runs in metal pipes. In the prototype constructed in Versailles, the water in the wall will be exposed to the air. The wall is built up with many Rasching rings which are plastic rings with a lot of holes. Water is dropped on the top of the wall where the Rashing rings separate the water to small particles. When the warm outdoor air pass-es through the water particlpass-es, the sensible heat in the air turns to latent heat which evaporates water drops to vapor. The outdoor air temperature de-creases through this evaporation while the humid-ity increases. The low temperature of the terrace reduces the heat gain to the living space while the humidity is physically stopped by the windows. This process will also remove the waste heat of the PV panels.
The Orchid house is composed with three main volumes such as the exterior envelop, L shape living area, and green core. The green core in the center of the unit serves as a buffer zone to moderate indoor and outdoor air, reducing the heating and cooling loads. It does not only enhance the verticality of exterior envelop to connect ground level and mezzanine level, but also act as green chimney to promote passive cooling effect in the house.
With potted Orchids and other vegetations, we want to offer the tenant a vertical green space, as what the Taiwanese rooftops use to be.
3. Green Core
Figure 1.2.2 Green Core View
3. Smart Skin
Shading is the most effective way to cool down a space. Orchid House have invented a smart skin which adapts to the surrounding automatically without power. The memory alloyed springs which connect to the leaves can operate by itself when the temperature reaches the setting of 26°C. This shading device is like skin which moves without electricity and animate the shadow on the floor.
Lighting effect Making of leaves
Smart Skin Variation Unit Installation
4.Material Selection
The Orchid House consists with main steel structural frame and series of box infill to incorporate dif-ferent type of insulation material. The insulation material will be selected by the local environmental condition as well as the financial condition of the house unit. Both steel structure and box infill will be prefabricated in factory near Taipei city for reducing carbon footprint during the transportation.
Most of building material for the basic structure for the Orchid House is easily recyclable materials:
Steel, Aluminum window frames, and simple glass. The Orchid House also integrates new material with sustainability concern such as Bayer Makrolon polycarbonate, MegaMaster eFoam insulation, and SPG’s 100% recycled glass foam insulation.
Façade
Polli-Bricks: Recycled, Recyclable, and Reusable
Polycarbonate Makrolon® polycarbonate: Recyclable and Reusable
Glass-louver: Recyclable
Structure
Steel: Recyclable and Reusable
Structural Plywood: Recyclable, Reusable, and Renewable
Floor
Wood Plastic Composite: Recycled, Recyclable and Reusable
Insulation
Glass foam: Recycled, Recyclable, and Reusable e-Foam: Recycled, Recyclable, and Reusable
Interior
Wood Furniture: Recycled, Recyclable and Renewable Technical Specs
Minimum Radius : 100
1. Steel
Sustainable Material Matrix