Energy and Low Income Tropical Housing Project (ELITH): Thailand
Thai vernacular houses were constructed from low-mass materials. Typically thatch was used for roofs. Walls were constructed from thatch or wood planks or even broad tree leaves. Roof eaves of such houses extend to provide shading of solar radiation. Windows and doors were open to allow good natural air flow for ventilation. Daylight from the sky provides sufficient lighting in the house during daylight hours. Floors were raised up by a full floor height, one consequence of which was the resultant upward flow of cool ventilation air from below. Such vernacular houses located among canals and water ponds were comfortable to live in. No heating or cooling was used. Embedded energy in the materials used for housing was low. Energy consumption to keep the interior environment comfortable was negligible. Artificial lighting was needed during night time only.
At present, electrification has reached over 99% of villages. Bottled liquefied petroleum gas (LPG) has become the most common cooking fuel. Electrical lighting, entertainment, and food preparation each accounts for about 15% of total electricity consumption of 2,680 kWh per annum of an average household. Amenities that include air-conditioning, use of electric fans, hot shower, and refrigeration account for the rest of over 50% of electricity consumption. Overall energy use per household is expected to increase by 2.5 times in 2030, while the number of households will increase by 25% and urbanization will increase from 43% to 64%.
Housing design has diversified greatly, in shape, size, configuration, and composition of materials. Materials for housing are now industrially produced. Low-to-medium income housing can be broadly classified into two category, individual detached house and condominium. In rural areas, low-income earners mostly dwell in detached houses. Most low-income earners also dwell in urban condominium. Most medium-income earners live in urban area and dwell in both types of housing. Medium-income earners will use air-conditioning in one or more rooms (such as the main bedroom and the living room). Low-income earners will use electric fan to achieve comfort. Present housing designs do not pay sufficient attention to ensure that daylight provides sufficient illumination during daytime.
Presently, there is insufficient effort and insufficient body of studies into the issues of low-energy housing for low-income and medium income earners. Even fewer studies have touched on the issue of thermal comfort for low-income housing. Modern housing design does not adequately attempt to utilize daylight fully nor to provide sufficient but energy-efficient electric lighting during night time. Even though a Building Energy Code for mandatory implementation on commercial building exists in Thailand, there is no such code for residential or other types of buildings. It is also perceived that a mandatory code for residential dwellings will not be accepted by the public at this point in time, but some schemes of voluntary energy labeling may be acceptable.
In the first part, this project will first identify criteria and energy performance indicators of building envelope, electric lighting system and air-conditioning system. Next it will conduct study on housing designs, thermal comfort, efficiency of energy use for lighting and thermal comfort, and the level of use of daylight in existing sample detached houses and condominium for low-to-medium income earners in selected urban areas. Similar studies will be made on sample detached houses in selected rural areas. The results will form baseline information for formulating key performance parameters on energy performance of building envelope, lighting, cooling, and overall energy use of main spaces. The results of the studies will also be used to define adequate level of thermal comfort in the main spaces in each type of dwellings. The overall results will be used to develop a scheme of rating or energy performance labeling of housing design for the two main types of dwellings studied.
In the second part, this project will conduct study on embodied energy of selected common construction materials. The project will then examine alternative material composition or construction methods. The results of the study will be used to provide recommendation to industry on alternative composition, alternative construction method, or alternative low-embedded-energy materials.
In the last part, the project will disseminate results: by publishing and providing assessment of energy performance levels of a number of housing designs in Thailand and other countries of same climate, providing training to building professionals, research networking and personnel exchanges (including students), and other means.
To assess baseline energy performance and the use of natural means for comfort, lighting, and ventilation in low and medium income housing in order to promote design of energy efficient housing through the use of energy performance labeling, training, and other means of information dissemination.
The ultimate beneficiaries are the low and medium income earners who will have access to low cost, comfortable, and low energy housing that contributes less to carbon emission. The academic institutions and housing design professionals will benefit from the results of research into low energy housing design that utilizes natural daylight and ventilation.
Mr. Preecha Tummu
Position: Research Associate
Ms. Kawita Hengmechai
Position: Research Assistant
Ms. Hathairat Loyprakhon
Position: Research Assistant