Daylighting – Making Bldg A a high performance building

On 12/8/2010 I attended a meeting on the High Performance Building Program given by two folks from the Governor’s Energy Office (Connor Merrigan and Paul Hutton).  They discussed the adoption of high performance building practices, and today’s topic was daylighting buildings. The twin aims of daylighting are to improve occupant comfort and reduce energy usage. They first discussed the importance of daylighting which includes better worker productivity, better test scores for students, and in one case Walmart found higher sales in parts of stores which had daylighting. Some folks rank daylighting just as important as nutrition.

Aspect is important in  daylighting. South facing, with direct sunlight, is simply too bright. The natural tendency is to close the blinds and turn on the lights (no energy savings there!). Rerouting direct sunlight to the ceiling and allowing it to be diffused over a larger area is one way to handle the problem of glare and bring daylighting advantages deeper into the building. We have an abundance of daylight in Colorado and only need about 1% or 2% of the foot candles we receive daily from the sun. One needs to get more daylight into the building’s core and keep it diffuse, minimize contrast, and avoid direct beam. Light shelves reflect the light to the ceiling  and help diffuse light and reflect it deeper into the building. Outside the building, sunshades and overhangs can shield areas where daylight may offer too much of a good thing.

For Building A, I think we need to have it assessed and several areas need to be addressed. One is the south-facing windows which could use sunshades or overhang. This could be very expensive. Another idea is the use of light louvres which can redirect the sunlight. For artifical lights in the building, I think we should have the capability to dim the lights and should look at daylight harvesters; there is no need to have all the lights on when we have so much daylight here. The Green Team will continue with this effort… who knows, maybe we can work in a daylighted environment, increase productivity, and save energy!