A Field Survey of Thermal Comfort in Air-conditioned Space in Songkhla’s Hot Humid Climate

This paper reports the study results from a field comfort survey of people in hot humid climate of Songkhla, a province in southern Thailand (latitude 7.20°N and longitude 100.59°E). Thermal sensation, thermal acceptability, and thermal preference were assessed from the observations of three hundred subjects in air-conditioned spaces in buildings. The analysis showed that the operative temperature for the thermal neutrality (TVS=0) was 26.3°C, and the acceptable temperature range (TVS=±0.5) was 25.6-27.1°C. The air movement played a key role to improve the people thermal sensation and preference, but the relative humidity performed less impact. In our study case, the PMV model could not well applied to Songkhla’s people as it predicted the neutral temperature one and a half degree colder than the actual, and underestimated the hyper-sensitivity of the thermal sensation to the temperature

PEDOT:PSS Nanofilms Fabricated by a Nonconventional Coating Method for Uses as Transparent Conducting Electrodes in Flexible Electrochromic Devices

Nanofilms of a polymer mixer of two ionomers, poly 3,4-ethylenedioxythiophene:poly(styrene sulfonic acid) (PEDOT:PSS), were used as conducting materials to develop transparent conducting electrodes. It was firstly found that convective deposition, a versatile and wide-area coating method, could be used for the coating and acid treatment of PEDOT:PSS films. Electrical conductivity of the PEDOT:PSS films was significantly enhanced up to 1814 S/cm by only one-time surface treatment by a mild acid solution (4 M methanesulfonic acid). This is because some PSS chains were removed out from the polymer mixer films without damage on the substrates. UV-vis-NIR spectroscopy, Raman spectroscopy, and cyclic voltammetry were used to characterize the acid-treated transparent conducting films. In this report, obtained transparent conducting PEDOT:PSS films on polyester substrates were used as flexible electrodes for fabrication of flexible electrochromic devices. Poly(3-hexylthiophene) (P3HT) was used as an active layer, which its color changed reversibly from transparent-light blue to purple with a small applied voltage (±3 V)

A new diffuse luminous efficacy model for daylight availability in Burgos, Spain

The determination of optimal illumination conditions in buildings is of great interest both for reducing energy consumption and for exploiting solar resources with greater efficiency and sustainability. The most commonplace method of estimating daylight is the luminous efficacy approach, using the more widely measured solar irradiance. In this present study, a new model of diffuse luminous efficacy over a horizontal surface is proposed. A comparative study of twenty-two classic models is presented, to obtain diffuse illuminance, using both, the original mathematical models and the adapted models with local coefficients, in order to determine the most suitable models for Burgos, a city located in north-western Spain. With this purpose in mind, twelve models are selected for all sky conditions, five models for modelling clear sky, two for partly cloudy sky, and three for overcast sky. These twenty-two models are then compared with the new model both for all sky conditions and for particular sky conditions (clear, partly cloudy, and overcast). The behaviour of the new model showed greater accuracy than most of the classic models under analysis. Hence, the advantage of the diffuse luminous efficacy model that can be applied both to all sky and to particular sky conditions.Spanish Government (Ministerio de Economía y Competitividad) (ENE2014-54601-R). David González Peña would also like to thank the Junta de Castilla-León for economic support (PIRTU Program, ORDEN EDU/310/2015)

Radiant Cooling with Dehumidified Air Ventilation for Thermal Comfort in Buildings in Tropical Climate

AbstractRadiant cooling is an alternative air-conditioning that havs been implemented successfully in high latitude regions. In tropical region as Thailand, radiant cooling is quite challenge due to its cooling performance being limited by high-moisture ambient air. This paper reports an investigation of radiant cooling in a tropical building. The study comprises full-scale experiments of a radiant cooling system with cool panels installed in a room of a laboratory building. A separate fan coil unit was installed to remove humidity of the ventilation air before suppluying it into the room. A software namely TRNSYS was used to model the systems in order to determine the heat extraction rate of the cool panels. Thermal comfort level in the room was evaluated by predicted mean vote (PMV) index. The results show that the radiant cooling is able to use for air conditioning for human comfort in tropical buildings. However, a sophistical system to control temperature of the chilled water supplied to the cool panels and the fan coil unit for the ventilation air dehumidification is inevitably required

POTENTIAL ASSESSMENT OF GREENHOUSE GAS REDUCTION IN PATTAYA HOTELS, THAILAND

Hotels in Thailand are one of the country's main economic growth sectors which inevitably result in increased sector energy use and cause a rise in GHG emissions. A study on the source of GHG emissions in the hotel sector can guide the suitable reduction measures. This paper reports the study results of the greenhouse gas (GHG) emissions and their reduction potential in 4- and 5-star hotels in Pattaya, Thailand. In the study, seven 4- and 5-star hotels participated in surveys to assess their GHG emissions from electricity use, stationary combustion, mobile combustion, refrigerant leak, wastewater, solid waste, and outsourced laundry. The data used in this study were based on the 2018 statistics. The average emission by the surveyed hotels was at 4,466.99 tCO2e/year, equivalent to 107.88 kgCO2e/m2-year, and 45.42 kgCO2e/room-night. Electricity use was the major activity accounting for 77% of the total emissions. Hence, the GHG reduction plan was put forth to the energy efficiency improvement of energy-intensive machines. The findings from surveyed hotels were used as the basis to estimate the GHG emissions and potential reduction for 4- and 5-star hotels in the whole of Pattaya. By the proposed improvement scheme, the potential to reduce the GHG emission was 13,818.28 tCO2e, for an equivalent reduction of 7.8% of the total GHG emissions. This study approach for GHG reduction can further be applied to other tourism hotels nationwide to support the country in achieving the national GHG emission reduction target and the sustainable tourism industry