Measured Net Energy Pergormance of Single Glazing Under Realistic Conditions

A new measuring facility, the MoWiTT, has begun operation with a study of the summer performance of single glazing in south-facing and east-facing orientations. These measurements demonstrated the MoWiTTs capabilities and provided a baseline for future measurements of more complex fenestration systems. The net heat flow through the fenestration was measured at fifteen-minute intervals over several days. Simultaneous measurements of air temperatures and solar intensities were used as input data for an ASHRAE calculation of the same quantity, assuming standard summer values for the film coefficients. Good agreement between measured and calculated heat flows was obtained when the vertical surface solar intensity was used as input and the calculation included the effects of window setback.