One of the major sources of heat loss is through windows and doors. A typical window or door has a U value of 1.60 (a good quality modern type) and that’s 5 times as much heat loss as a wall with a U value of 0.32. So it helps for windows to be as small as possible. The sun pipe is used to create a very small window.

The sun pipe is a round dome with a diameter that varies from 0.23M to 1M. It can be much smaller than a traditional rooflight or window if you want it to be. You can use one the size of a standard fluorescent light and even attach a cover to the other end which is the same as the cover for a fluorescent light. This enables the sun tube to directly replace fluorescent lighting. The sun pipe can either be attached to a roof or a wall and is then attached to a metal tube which the light can travel down. The metal tube can be very short or very long and it can go around corners. Sun tubes are not restricted to the rooms in the roof or on the top floor. The light can be piped anywhere. The effect of the sun pipe is very attractive. The quality of light from a sun tube is very much superior to an ordinary fluorescent light. You are likely to think, wow, what beautiful light.

In industrial buildings there are large areas which are actually very difficult to light with windows. These buildings traditionally are full of powerful electric lights which consume massive amounts of energy. Sun tubes can provide the same amount of lighting in the building without electricity during daylight hours. A huge chunk of an industrial building’s energy consumption is due to these hugely powerful electric lights.

Will we one day have houses without windows? I doubt it. We need windows to look outside. It’s a legal requirement for some rooms to have windows. A bedroom with no windows would feel strange, even if it was well lit and well ventilated. The room I’m in at the moment has one small window and that doesn’t feel too bad, except that we need the electric light on most of the time. If we used sun pipes we wouldn’t. We could end up with houses having much smaller windows and areas of glazing with sunpipes giving most of the light.





Tagged on: