Comfort & Indoor Air Quality
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Human thermal comfort depends on a range of climatologically and physiologically related parameters as shown in the diagram. In a tropical climate context, a person will be increasingly uncomfortable with increased air temperature, humidity and radiant temperature (temperature of the surfaces surrounding the person). Increased air velocity and reduction of the clothing level can help in improving the comfort level. |
The recommended indoor temperature range from 23oC to 26oC and the recommended relative humidity is 60% - 70%. As both the required temperature and humidity parameters are lower than outside air, full climatization is normally required for the working areas, in order to satisfy optimal human comfort and working condition. Buildings therefore have to be tight, and the fresh air intake has to be controlled for optimum quality of the indoor air. In the LEO Building, intake of outside air is controlled according to CO2 level of the indoor air, and thereby controlled according to the occupancy level. The more people in the building, the more fresh air intake required.
It is noted that low temperature and low humidity is uncomfortable, unhealthy and expensive. Office air temperatures lower than 22oC to 23oC mean that people will have to dress up with warmer clothes, and cooling load of the building increases. In the LEO Building, a reduction of the office air temperature from design level of 24 degrees to 20 degrees increases the energy consumption by 33%!
In the LEO Building, the quality of the indoor air is further improved by the use of electric air cleaners, instead of normal fibre filter to clean the incoming air from particle pollutants.
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