09.07.2017 - COMFORT CONTROL IN BUILDINGS
Comfort in Buildings
There are several comfort types in buildings. While think about comfort for the buildings, first idea always comes as thermal comfort but there are other issues related with comfort subjects for buildings. These are, in orderly, thermal comfort, visual comfort and indoor air quality.
'That condition of mind which expresses satisfaction with the thermal environment.'
Thermal comfort constitutes form different elements. 4 of them can be calculated by sensors easily, which are air temperature (◦C), radiant temperature (◦C), indoor air velocity (m/s) and air relative humidity (%). The other hardly calculated factors depens on humans perception these are clothing insulation (m2 ◦C/W) and metabolic rate (W/m2). To calculate thermal comfort, Predicted MeanVote (PMV) index, developed by Fanger, during the 1970s to guarantee the thermal comfort of humans. The PMV index foretells the mean response regarding thermal sensation of a large group of people exposed to certain thermal conditions for a long time . The value of the PMV index is a seven-point thermal sensation scale. For specific zone of thermal comfort, different standards recommend to provide the PMV index at level 0 with a tolerance of ±0.5.
The lighting for zone there are three main properties consider about it:
- Provide enough enlightment for people's own security to see each other and obstacles
- Augment visual performance of people
- Define easy reachable zone by visual perspective
Besides that, it won't be enough to use just natural illumination to reach these three task. There has to be considerations about artificial lightning composition and shading devices position and dimension. To calculate visual performance of place, there are several indices such as illumination levels, glare and colour rendering.
Indoor Air Quality
Most of the works which can be found in literature use direct CO2 concentration in order to reach indoor air quality.Typical indoor air quality calculates according to CO2 level. Within the scope of 'Comfort Control in Buildings,2014' a detailed index is proposed: the Indoor Air Quality (IAQ) index. IAQ index is estimated based on indoor CO2 concentration and the classification provided by the international standard (prEN 13779).To explain better, it has been considered an optimal indoor air quality for CO2 level under 500ppm, and thus, the IAQindex is less than or equal to zero. IAQ index can get values below 0 to 1. While it goes to 1 it gets worse of air quality index.
the formula : IAQ = 0.001CO2in −0.5
- Comfort Control in Buildings, María del Mar Castilla José Domingo Álvarez Francisco Rodríguez Manuel Berenguel, 2014, Springer.
- Fanger PO(1972) Thermal comfort analysis and applications in environment engineering. McGraw Hill, New York
- IDAE (2007) Reglamento de instalaciones térmicas en los edificios (in Spanish). Technical report, Ministerio de Industria, Turismo y Comercio, Spain