Predicted versus measured performance: how well do the passive solar design manual predicted values compare to measured performance?

A recently published manual details the latest revision of the Solar Load Ratio (SLR) method. The SLR method, which uses simple ratios to predict performance of passive solar systems, provides a design tool that can be easily applied by the solar designer. This paper compares the predicted monthly auxiliary energy requirements obtained using the SLR method to those measured at 11 passive solar systems. Measured data used were obtained from the 11 passive solar systems.