A reader's Roofs and roofing question: Tubular skylight?

Paul   from   Queensland, Australia   had this Tubular skylight question.

HI Bill (no - deck isn't finished yet - too slack and screwing boards at 45deg takes AGES)

Skylight question if I may.
I have seen two types of tubular skylights ones with flexible tube, and ones with rigid tube. The rigid tube guys claim much better performance, but at 2x the cost.
Do you have any comments?
Also - as a Darwinite - what's your thoughts on with skylights on getting the light in - but keeping the heat out?
Thanx Paul

Bill's answer

Hi Paul,
I did a small bit in my newsletter the other day about skylights etc. I have been reading a two page article BPN (Building products Review) and it seems that the range of natural lighting systems is getting really sophisticated.

The traditional Solatube that uses the spiral reflective A/C ducting (wasn't that a brilliant idea, using existing cheap as chips technology for a completely new application) is still a good option in my opinion.

I have seen quite a few that are working well. I have not seen any of the polished aluminium tubes (or the others with highly specular high tech coatings) but you can only believe what they say about performance.

I guess you will have to do a bit of research. For us up here we diffuse them, so to get maximum performance is not an issue.

If the difference in cost is so much, I'd be tempted to put in two cheap one's if needed.

Mentioned in the BPN article is the Solatube "Brighten Series" that so far are the only ones that have been tested under proposed new regulations.

Check out Skytubes.
Also DayRay and Skydome are producing systems that use optic fibres as the delivery systems, which means that they can go around structural elements like walls or along ceilings etc. Very expensive of course.

Just about all the ones I have seen, tubes and skylights have diffusers on them and the range of diffusers, UV filters, ventilation etc is also growing.

When I built verandah roofs to existing houses, a problem was that the new roof reduced the amount of light coming into the kitchen window. Worktops were darker.

We solved this a few times by putting a couple of sheets of polycarbonate sheeting at the window locations. The best one that we used had strips of silver foil, 10mm wide with 10mm gap, that cut the light down to acceptable levels. I am not sure what the name was, Alsinite ?, or even if it is still available. I have often thought that it would make an excellent and cheap skylight if it was used in a main roof over say a bathroom.

One thing I said at the end of my piece in the newsletter, I have never seen a skylight etc. that didn't improve the amenity of a room. They are great. The fact that they also save money on not using electric lights is just a bonus.