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Moisture and Heat Transfer Analysis Tools
(for Residential Buildings)

Current Versions: BMOIST 1.0, MOIST 4.03

Developed at Ray W. Herrick Laboratories, Purdue University

This site allows access to two public-domain computer software programs that predict heat and moisture performance for residential buildings. The program MOIST 4.03 is an update to the MOIST 3.0 program that was developed at NIST (National Institute of Standards and Technology). It considers an individual exterior wall and uses weather data and fixed indoor conditions (temperature and humidity) to simulate both time and spatial variations in moisture and thermal conditions. BMOIST 1.0 considers both time-varying external and internal conditions and simulates a complete building to estimate moisture and thermal conditions. In addition to including the detailed models for exterior walls from MOIST, it includes the effects of wind and thermally driven infiltration, internal moisture storage within internal walls and furnishings, moisture removal due to HVAC equipment, thermostat controls, etc. It also includes a model for an unconditioned attic space. The development of MOIST 4.03 and BMOIST 1.0 was sponsored by NIST.  It is important to note that these programs were developed under Windows XP and may not operate properly in newer operating systems.