Couvillion, R.J. , J.S. Hawisa, and G.J. Tatge, (1992), "Apparatus for studying transient heat and moisture transfer in fiberglass batt insulation", ASHRAE Transactions, 98(2).
Abstract:
The overall objective of this work was to measure transient moisture content and twiperature distributions in a 6 to 12 in. (15.2 to 30.4 c?n) thick slab offiberglass batt insulation. 7he data were needed to mify a model of heat and mass transfer in fiberglass with diurnal varying ternperature and hwnidity boundary conditions. 7he cwrimentat setup was designed as two primary subsys-tem-(I) a hwnidityltmperature control system to main-tain the desired diurnal variation at the boundary of the slab and (2) a gamma-ray attenuation syste?n to measure the moisture content distribution within thefiberglass slab.
The humiditylte?nperature control system uses a chiller to &y the air and steam or water to hwnid6 to the desired kmi. Electric resistance heaters control the temperature. 7he system can produce sinusoidal or any chosen diurnal variation rangingfrom 5 *C to 50 * C and 20 % to 80 % RH.
The moisture content measure7nent syste?n uses a collimate,dAm-241 gamma beam. A second source, Cs-137, was availablefor use in a dual-source mode but was not needed. Approxbnately two minutes are needed for each moisture content measurement, and moisture contents ay low as .01 glg, corresponding to a relative hwnidity of 10%, can be measured. 7he syste?n measures moisture content at eight points within the slab.
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