Transient heat and moisture transfer through building envelope under rain precipitation
Matsumoto, M.
1995 International Symposium On Moisture Problems In Building Walls, Porto - Portugal, 11 - 13 September, pp. 319
Matsumoto, M., (1995), "Transient heat and moisture transfer through building envelope under rain precipitation", International Symposium On Moisture Problems In Building Walls, Porto - Portugal, 11 - 13 September, pp. 319.
Abstract:
To evaluate energy demand and durability, thermal and hygric behaviors of buildings are to be analyzed under natural climate, treating buildings as total thermal and hygric system. Buildings are subdued to various natural climatic conditions which vary with time. Models for reliable prediction is to be applicable to those conditions. Building components are subjected to wide range of moisture potential such as from low (hygroscopic) level to near water saturation.
From this point of view, a mathematical model for prediction are presented which is applicable to either non-freeing region or freezing regime.
In this paper, using the model dynamic behaviors of moisture and temperature in building elements are analyzed under rain precipitation, of a moisture absorbing exterior envelope as an extreme condition. Numerical analysis is performed of a air conditioned room sensible and latent heat load are calculated. Effects of rain intensities are discussed. Cooling effects of moisture evaporation after rain precipitation are shown. it is shown that cooling effects by moisture evaporation are apparent on sensible heat flow. On the other hand, they are compensated by increase of latent heat load by moisture inflow to room and increase of conduction flow by thermal conductivity increase due to higher moisture content are shown. Effects of moisture barrier on inside wall surface of the are discussed. It is shown that thermal effects of rain precipitation we distinct and must be considered to predict heat load of buildings.
Saved to "governing equation for heat and moisture transfer.doc"
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