What the experts say

Dulux Trade recently commissioned independent company Building Research Establishment Limited to carry out strict testing to assess the impact of paint type on light levels in rooms, using 1:7.5 scale models of rooms decorated using different paint colours.

Four model rooms were tested, each one simulating a small domestic room 4m x 3m x 2.45m high. The models were illuminated either with simulated daylight (from an artificial sky with cool white fluorescent lighting) passing through a side window, or with tungsten lighting placed centrally below the model's ceiling.

Enlightening results

Overall the conclusion was that higher reflectance paints DID give significantly increased illuminances inside the model rooms. In reality the relative improvement from high reflectance paint is likely to vary from room to room. In rooms with down-lighting lower relative increases could be expected, while in rooms with up-lighting, or indirect lighting, higher increases could be obtained. Light & Space gave the biggest relative improvements in illuminance in the darker areas of the rooms, so it could improve the feeling of space by making dingy corners less dark.

Energy savings can be expected

The findings show that using Light & Space could result in lighting energy savings, for two reasons: Firstly, it is possible that less electric lighting could be installed, if the designer and the building manager agreed that high reflectance paints would always be used in that room. Secondly, the increased levels of daylight could mean that electric lighting would be required less of the time, provided that suitable controls were fitted to turn off the lighting when daylight was sufficient.