WUFI Analysis

WUFI is a program for analysis of heat and moisture changes over time in building envelopes. I have had successful experience in applying WUFI analysis, along with other similar mathematical analyses to building walls and roofs. It can be very revealing of moisture problems caused by poor design, or inappropriate material use. Or if used in the design stage can prevent problems. Results of WUFI analyses incorporated into an expert report have been effective in gaining more favorable settlements for attorneys I have worked with. As a rule of thumb I will do a WUFI analysis for any case that has moisture problems involved in it. WUFI analysis is also offered as a discrete service.

This movie shows the values that WUFI is finding for temperature, humidity, and moisture content as it applies the environmental conditions from the outside weather to a wall that is conditioned for comfort on the inside. WUFI is balancing the drives for heat and humidity hour by hour. The clock face at the upper right changes to a darker color for night time and lighter color for daytime. Rain and intensity of rain is shown on the lower left by the logrithmicly scaled blue bar where clouds apear above it when it rains. Total solar radiation on this eastern exposure is indicated by a yellow sun on the upper left side, it is significantly higher in the morning hours when the sun provides direct solar radiation in addition to the sky radiation. The direction and size of the pink arrow shaped bars at the top of the upper graph show the direction and magnitude of heat flow between material interfaces. The direction and size of the blue arrows at the top of the bottom graph show the direction and magnitude of vapor drive at material interfaces.

Coastal Virginia Tilt-Up Wall
This example shows the summarized results of a tilt-up precast concrete building wall with (top illustration) and without (bottom illustration) a kraft paper vapor retarder beneath the GWB on the inside. The blue at the bottom of each graph shows the accumulation of water in the wall. In this case the vapor barrier should not be used because of warm weather moisture collection outside of the vapor retarder.