Naturally Tokyo: found in translation?
BT-Bundle |2020
choices can be made. It was clear that as Tokyo’s temperature is warmer than Amsterdam’s, focus needs to be given to cooling rather than heating. The challenge: space is limited in Tokyo hence the proposal of making SC as a plug & play unitized system.
Earth, Wind, and Fire (EWF) is a natural ventilation system developed by Dr Ben Bronsema for office buildings in the Western European climate. Powered by nature: ground temperature & gravity for cooling, wind for energy generation & ventilation, and sun for the heat and natural draft, this system claims not only to use little energy but also naturally purifies while humidify/dehumidify the air. No study has been done to see the performance of the system in a warmer climate, such as Tokyo. This thesis intends to answer that with the following research question: “Is the Dutch EWF, in place of the existing air-conditioning system, an efficient energy-retrofitting method to achieve energy-neutrality in an office building in Tokyo without compromising thermal comfort of users?”
Armed with a case study integrating EWF into a relatively new 10-story medium-sized office building in Tokyo, the study explored and compared 4 different systems: the existing energy-conscious VRF system, conventional VAV system, EWF with chilled ceiling, and EWF through chilled beams, as shown below. As a conclusion, EWF can contribute to energy reduction (40%) without compromising thermal comfort in comparison to the conventional VAV. Regarding VRF, further research needs to be done to properly simulate EWF with HR in the dynamic simulation software used. Moreover, EWF contributed to ventilation energy reduction in all cases evaluated, as well as improving thermal comfort.
The 2 dynamic duo of EWF: air supply system called Climate Cascade (CC) and air exhaust system called Solar Chimney (SC) are sized and calculated using 2 separate Excel models, from which the key parameters are identified and design
SUMMER Climate Cascade
1. VAV
2. VRF
3. EWF with chilled ceiling
4. EWF through chilled beams
Solar Chimney
Pre-cooled air to CC 27 °C
Air at the top of SC 25°C
12.5 °C
21 °C
Outside air 31°C efficiency 70% air medium
Space Cooling to 28 °C 28 °C
Heat Pump
Chiller
15 °C
Chilled ceiling
28 °C
15 °C
15 °C
28 °C
Cold Storage
Ground temperature 15 °C
11 °C
Heat Storage 19 °C
WINTER Climate Cascade
Pre-heated air to CC 18 °C
12.5 °C
!
The variety of systems explored
Solar Chimney Air at the top of SC 22°C
14 °C
Outside air 9 °C efficiency 70% air medium
Twin Coil
Air Heating to 16.5 °C
(when necessary)
35 °C
Heat Pump
Chiller 17 °C
11 °C
Cold Storage
Space Heating to 20 °C
20 °C 25 °C
Floor heating
19 °C
Ground temperature 15 °C
11 °C
19 °C
Summer & Winter scenarios
Schematic section of EWF in NK Building, Tokyo
Name Graduation year Tutors 12
Heat Storage
Corresponding temperature distribution
Solar chimney as unitized system: opaque block, transparent block, and frames
Puji Nata Djaja 2021 Regina Bokel & Alejandro Prieto
