A RESPONSE-FACTOR METHOD FOR CALCULATING COUPLED HEAT AND MOISTURE TRANSFER IN BUILDINGS

摘要

Analytical solutions for coupled diffusion of heat and moisturernthrough a material are used to develop a generalisation of thernwellknown 2 x 2 matrix method for describing heat flow only. Arnnew 4 x 4 matrix is derived which relates temperatures, humidities,rnheat flows and moisture flows at one surface of a slab with those atrnthe other. Multilayer slabs and surface boundary conditions,rnincluding moisture-impermeable surfaces, are easily handled byrnmultiplication of matrices. The method is we ll suited forrnimplementation in an existing program, CHEETAH, which wasrndesigned to calculate hourly temperatures and sensiblernair-conditioning loads in small buildings, using real weather data.rnThe new version calculates hourly absolute humidities and latentrnair-conditioning loads in addition to temperatures and sensiblernloads, taking into account the effects of outdoor air temperaturernand humidity, solar radiation, ventilation, internal sources of heatrnand moisture, and the presence of adsorbing materials. This paperrnbriefly outlines the theoretical basis of the method, and presentsrnsome results showing the effects of adsorbing materials onrntemperatures and humidities in a simple building.