Water Silhouette
Perpective
Proposed Typical Floor Plan with Atrium
Roof Canopy
Proposal for NAI Rotterdam Delft Seminars on Building Technology | Spring 2017 | Puchun Zhang
Water Silhouette : An Energy Efficient Building with Natural Solar-Water Heating System The proposed design for NAI Rotterdam uses water as a natural heating and cooling medium to make the building sustainable. The design concept concerns architectural experience as well as energy efficiency. By using water as a resource, the proposal also brings possibilities for facade patterns and aesthetics, as well as a new identity for the institution in the city. The sustainability design centres on four major aspects: energy, ventilation, water and lighting. Architectural Concept The proposal begins with an overall concept to improve the architectural quality and provide the building with a new identity. In order to provide more sun-lit space and a sense of community, a roof-top greenhouse is integrated into the building with an atrium below it, increasing the open area for diffused sunlight and ventilation. The roof becomes an accessible terrace with a solar canopy which can be open or closed depending on the weather. The solar-thermal units running throughout south and east facades flows along a curvature pattern, giving the building a new silhouette appearance.
Overall System Diagram
Energy Concept: Water Heating and Cooling The water circulates all over the building as it heats or cools the building. The system consists of two parts: the solar-thermal units above ground, and the seasonal heat storage unit underground. The concept is to collect as much heat as possible in the summer, store it in the water tank heat collector in the basement and use the hot water to heat the building in the winter. It works together with solar heating units on the facade and roof of the building. The diagrams show four scenarios for the heating system: First, during summer daytime, cool water from the heat storage runs first through the floor slabs, cooling done the indoor space and being pre-heated before it reaches the roof and facade solar heating system. The heated water then runs back to the seasonal heat storage system through a heat exchanger and repeats the cycle. During summer nights, water runs first through the floorslabs, maintaining floor slabs cooling demands, then through the facades and back to the tank. In the winter, the reverse of the summer situation would be conducted to heat the building. During winter daytime, hot water from the heat storage would first go through the solar thermal panels on the facade and the roof to be further heated before entering the interior. It then runs through the floor heating system to warm the building, back to the water tank through the heat exchanger. During winter night time, water will circulate between the storage tank and the floor pipes to conserve energy and maintain minimum heat requirement. Ventilation Concept: Central Atrium and Double Skin Facade The atrium and facade function as devices for natural and stack ventilation. It facilitates air movement from the lower levels to the upper levels.
Roof Greenhouse
Water Cooling/ Heating Diagrams
Rain Water Collection
Seasonal Heat Storage
Summer Day
Three scenarios are shown by the ventilation diagrams: During spring and autumn, when the outdoor air temperature is comfortable, outdoor air is let in by the openings at the bottom of the facade, entering the building and exhausted through the top of the facade. The greenhouse also drives the movement of air upwards and escape from the atrium. During summer time, air is actively cooled and induced into the building. It will then rise and escape through the top of the facade and the greenhouse. During winter time, the double skin facade is completely closed on top and bottom, as a buffer zone that helps to insulate the building. Exterior air is actively heated and then induced into the building, raised and exhausted through the greenhouse openings. Water and Lighting The roof canopy is a device that serves to collect rainwater. Its rotating panels tilt up when it is sunny to maximise solar gain, while lay flat when it is raining to collect water. Water will then be transported to the water storage and pumped into the building for non-portable use. The solar thermal panels on the facade also function as a shading device to provide optimised daylight by reducing direct sunlight in the summer and increase sunlight in the winter.
Summer Night
Winter Day
Winter Night
Ventilation Diagrams
Seasonal Heat Storage
Spring/ Autumn
Summer
Winter