Measuring the Daylight Performance of Classrooms: Can a One Point Sensor Measurement Predict the Daylight Distribution within a Space?

The New Zealand Ministry of Education (MoE) has begun measuring the light, temperature, noise and CO2 level of 21 selected schools using a single sensor. This sensor is being developed as a method for routine measurement in order to understand the performance of New Zealand's school buildings. This study used a Climate Based Daylight Modelling to appraise the MoE methodology, to determine what can be learned from the use of a single sensor in one location in a classroom, to estimate the lighting comfort across a space. Daylighting is focused upon because it has the most spatial variation in a space. The findings of this study support the assertion that a one-point sensor measurement on a vertical wall could predict illuminance across the centre of the horizontal work plane; and provide a useful benchmark to estimate the light distribution across a space. However, regardless of how representative of a space a one-point measurement is, it is difficult to quantify the daylight distribution over time throughout the space. If various daylight indicators are well documented and analysed alongside the measured data, a strategically positioned one-point sensor on the vertical wall could be useful in predicting the daylight quantity of a space.