hygIRC 1-D V. 1.1 is a user-friendly, one-dimensional version of NRC-IRC's hygIRC, a state-of-the-art hygrothermal model (see Construction Innovation, Vol. 8 No 3) developed to help building design professionals choose optimal building envelope components and systems.

The model simulates the response of each element to changing environmental conditions on either side of the envelope on an hourly basis. This produces information on the temperature and relative humidity distributions within the wall assembly and the changes over time. The model comprises the recently benchmarked hygIRC solver, a weather database containing 30 to 40 years of hourly weather data for 25 North American cities, models to simulate interior temperature and relative humidity conditions, and a material database containing the hygrothermal properties of 80 common construction materials (the most up-to-date in North America) as measured at NRC-IRC.

Provision has been made for users to employ their own weather, interior conditions, or material property data, where appropriate. hygIRC 1-D also provides easy-to-use tools for output analysis. Time series plots of temperature, moisture content and other output parameters can be viewed for the wall layers or the entire wall, where applicable. hygIRC 1-D also contains the freeze-thaw cycles and RHT Index output measures developed for use with hygIRC (for more information, see Construction Innovation, Vol. 8 No 1). Users can also animate the results to give a picture of the wall response over time. The framework of hygIRC 1-D was built to facilitate case studies allowing the user to readily conduct parametric studies, studies where several parameters are changed one a time to gauge the sensitivity of the wall response, or "what-if" scenarios such as what if the stucco cladding were replaced with acrylic stucco. Situations involving air leakage, water leaks, and gravity are, however, still best handled using the two-dimensional version of hygIRC.

Potential users

The program is targeted to engineers, architects, building scientists, contractors, and students, but is of interest to anyone interested in investigating the transfer of heat, air, and moisture through common construction materials.

Contact: hygIRC 1-D development team