The thermal comfort of its user is a major consideration in designing a building. Selection of glass type window in designing a building in one of the major consideration by attaining thermal comfort.
The objective of this study is to differentiate the heat transmission through tinted glass window, and clear glass window. The study is conducted by experimentation to differentiate the glass window (clear glass, tinted glass) with the use of devices(normal thermometer), that can measure the temperature inside the building. This will show the advantage and disadvantage of each material that affect the thermal comfort of the occupants as well as the temperature inside the building.
Keywords: Heat transmission, Building envelope, Clear glass window, Thermal comfort, Tinted glass window
Thermal comfort is the major consideration in building envelope. To attain the comfort of its user the building it must be well-designed. Thermal energy is responsible to temperature that we called heat transmission.
Glass is the one who can give the light inside the building through sunlight. Through sunlight, heat transmission can enter into the building that can create heat and the natural light inside the building. Natural light is better than artificial light inside the building and if a building using artificial light by some other means necessarily require energy that can provide thermal conductivity of a building. Heat can enter the building through the building materials from warmer and cooler materials in wall, ceiling, roofs, and etc.
Now a days, there are a lot of discoveries material to utilized the heat transmission inside the building, to attain the temperature. One of the discoveries are tinted glass window. Tinted glass window is applied by darkened lenses to utilized the heat transmission.
Most likely, glass, as the material has thermal conductivity value of 0.78 W/m·? (Cengel, 2008, table 9.1.0). Moreover, there are different types of glass that own their peoperty and thermal performance. The float glass window is the most commonly used in commercial. Float glass window is classified in different types and among these are clear glass and tinted glass. (Odcstle Building Envelope, 2011).
The objective of this study is to compare the difference of clear glass window and tinted glass window as regard to heat transmission. Hence, the window is way of giving natural light inside the building as well as the visual connection to the outside.
How does the tinted glass window compare to clear glass window as regard to heat transmission?
This study aims to know the difference of the clear glass window, and tinted glass window in heat transmission as conducted in an experimental type of quantitative research. To measure their temperature in each type of glass window. I use two model building, one model building is for clear glass window and the second model is for tinted glass window.
The model is oriented to the sun path to catch up the sunlight. The data are taken in every one hour by using a normal termometer, starting at 7 am in the morning until 4 pm in the afternoon. The gathered data will plot on a graph to know the difference of their temperature in clear glass and tinted glass.
Figure 1. Normal Thermomete
RESULT AND DISCUSSIONS
TIME CLEAR GLASS
TEMPERATURE TINTED GLASS WINDOW
29 º 27º
30 º 28.9º
33.5 º 31º
35.4 º 34º
36 º 34.8º
34.8 º 33.2º
33 º 30.1º
32.3 º 28.7º
28 º 26.2º
Figure 2. Temperature data of clear glass and tited glass window
The gathered data is taken through the use of normal thermometer and placed inside the building model. Based on the gathered data, the line graph shows that the clear glass window is warmer than a tinted glass window. The tinted glass window lessen the sunlight penetration and heat transmission inside the building. On the other hand, tinted glass window can cause extra use of energy through artificial lightning. Clear glass window can create natural light throughout sunlight penetration which is good. While the heat transmission of clear glass window greater than tinted glass which can cause the extra use of artificial cooler.
Based on the gathered data that conducted through the experiment, tinted glass window, lessen the sun light and it is possible to use artificial lighting and lessen the heat transmission inside the building. As well as the good thing about clear glass window it gives natural light than to provide artificial light and can save energy, but it actually warms that will make the occupants uncomfortable. The clear glass window and tinted glass window is somehow good in a building, but it has a limitation to use, especially in the condition of the environment of the building. The gathered data explain that each type of glass has different temperature.
Thermal comfort of the occupant is always a major consideration in the building. Glass is the gateway to enter the sunlight and the heat inside the building. Glass selection in terms of thermal comfort must be chosen well. If clear glass is used in the building its better to have louvers to reduce the heat transmission and it would be also better if there is present trees around the building to minimize the heat transmission inside the building and to make the outside environment cooler. Tinted glass window somehow good in terms to lessen the heat transmission, but it blocks the sunlight.
Selection of the glass window in designing a building is one of the significant consideration, espicially in the condition of the environment of a building. The climate is one of the factors to consider the glass type to use, whether a clear glass window or tinted glass window. Based on the result of the gathered data, the recommended glass window to use is tinted glass in tropical countries.