溫室之心 The Mind Of A GreenHouse, Nangqen

video

2018 project developers:

Wiriya Rattanansuwan, Shih Wei Chieh
principal of Tashi Gatsen Charity School: Tsansar Kunga
land owner: Tsngsar Metokk
local coordinators: Tsangsar Tsueji, Tsansar Mohji

Project Introduction

This is an on going research project in Tibet, I joined this charity project voluntarily since August 2018 with Wiriar Rattanansuwan, a climate engineer from Thailand. The project goal is to build a solar greenhouse in Nangqen which can resist -20Cº to -30Cº during November to February in Nangqen. The altitude of the site is ~3,700 meters; the main task is to provide vegetable year-round for for the orphan children sheltered by the school. Another main task of this project is to research a common ground for both charity project and art, science project. The reason of it is to de-alienated artist or scientist from other capital systems, to innovate a transdiciplinary production system, social design. Also I believe the innovative project collaborating with the local community will bring more attentions to the situation of these developing areas.

Design

In the first phase of the design, we tried to employ many solutions and assemble them into one design. Solutions including earth battery, pit-house, earth-sheltered design to make a passive solar house.

Pit-house

The history of pit-house can be found here. We decided to make our one two meters deep due to the extreme weather in Nangqen. It was made of white iron frame and transparent Polycarbonate, PC boards with multilayers, sealed with silicon. We use bricks to build the walls underground to maintain the basement shape. We didn't put the bricks as floors, so the plants grow on the floor.

Earth Battery

For the earth battery part, we connected a underground PC pipe to the house, in order to drain the cold air out and circulate it back to the house after heat it underground through a 11 meters long tube.

IoT Weather sensor

Unfortunately we only finished the 80% construction before my flight, I also didn’t install the IoT Raspberry Pi as weather sensor successfully, but I was able to read the temperature value headlessly by ssh communication. Inside the house is proximately 4 to 6 degrees warmer than the outdoor temperature.

from airport to our site.

The house is 4*6*2 meters in size, 2 meters deep in depth. We thought about to make the roof with glass windows but luckly and eventually I choose transparent PC with multiple layers. I am very glad I made the choice due to its’ lightness and cheap price, and it’s much easier to install compare to the glass windows. However I only sliced the whole roof into 9 pieces which cause a big problem for the installing, it’s better to be sliced with more pieces so we can install it easier

Earth battery and earth sheltered house

Earth battery, earth sheltered greenhouse, were the two major prototype of our first design. There wasn’t enough time to accomplish the earth battery part when I was there since this is our first attempt because I didn’t find good pipes there for the air circulating. The earth sheltered design worked well, according to the feedbacks from the local community after I got back to Taiwan, they say they sweat and they see water dripping inside which proved the indoor temperature is above zero in the winter time. They also tell that they feel dizzy want to puke after long staying in it, I guess that is because we only have installed one fan for the air circulating and that causes short of oxygen and too much CO2 inside.

Roof design

Roof angle and house orientation: by the coordinates longitude: 32.8250 latitude: 97.1250, we got the sun azimuth angle around 79º, and our roof slope should be 23º. The greenhouse is facing to south with 11º degrees counterclockwise turned in order to get the maximum sunlight.

OPV test for NTSU, 成功大學

OPV provided by professor Meng Hsin Fei from NTSU, These OPV has relatively very low watts, it is used to power one small fan I found from local electronics shop for cold/warm air circulation.
I didn’t find a good fan with proper size.
, although the fan was quite small but still able to make strong wind. Those OPV was placed inside the greenhouse, unfortunately it was not able to get the battery full charged and the OPV all didn’t survive from the weather. I think it might be the cracks on the OPV caused the oxidation inside the protection glass.

Construction

progress photos.

The weather station

I tried to install one RPI board with v2 camera module with it, but I didn’t make it. It took me 3 or 4 days to find a local internet cafe to install Raspian. They were quit paranoid to see I was working with wires and codes in their cafe, so I quickly got kicked out. Eventually I made it done and has successfully get the sensor datas, camera vision via ssh. Unfortunately I didn’t have time to install it properly inside the house before my flight to Taipei.
weather data station by Raspberry Pi (library: https://github.com/nickoala/sensor)

Latest result:

DIY raised beds and the vagetables growing conditions. The vagetables in pictures are taken around Janurary 20th, it was plant in Novemeber 5th, the growing is very slow due to the coldness. It is averagely -20 degrees from Novermber to December, however inside the greenhouse can be up above 0 degree so the water are still in liquid form inside. The problem now is the soil and we didn’t chose plants has higher resistance to cold to grow, we will select plants grow in cold weather in phase 2 of the project, which will take place in April 2019.