An Investigation on the Human Thermal Comfort from a Glass Window
Keywords:Glass window, thermal comfort, mean radiant temperature, operative temperature, percentage of people dissatisfied (PPD).
The effect of the glass window on the thermal comfort of a person sitting near the glass window is investigated by performing the experiment in a test room. A clear glass window and a tinted glass window are chosen to be the test windows in this study. The index chosen to describe the thermal comfort is the percentage of people dissatisfied (PPD). The important parameter for evaluating the human thermal comfort condition is the mean radiant temperature. The mathematical model for predicting the mean radiant temperature is presented. The predicted mean radiant temperature and the mean radiant temperature evaluated from the operative temperature are compared. The agreement is good. It is found that the mean radiant temperature, the predicted mean vote (PMV) and the PPD are all dependent on the transmitted solar radiation and the surface temperature of the glass window. Higher value of the mean radiant temperature yields higher value of the PMV and the PPD. The room with a clear glass window installed has high thermal discomfort condition mainly from the solar radiation. The amount of the thermal discomfort is directly varied with the amount of the transmitted solar radiation. For a high transmittance glass window, the thermal discomfort due to solar radiation is greater than the thermal discomfort due to surface temperature. For a low transmittance (high absorptance) glass window, the thermal discomfort due to surface temperature becomes important when compared to the thermal discomfort in the part of solar radiation.
Authors who publish with Engineering Journal agree to transfer all copyright rights in and to the above work to the Engineering Journal (EJ)'s Editorial Board so that EJ's Editorial Board shall have the right to publish the work for nonprofit use in any media or form. In return, authors retain: (1) all proprietary rights other than copyright; (2) re-use of all or part of the above paper in their other work; (3) right to reproduce or authorize others to reproduce the above paper for authors' personal use or for company use if the source and EJ's copyright notice is indicated, and if the reproduction is not made for the purpose of sale.