OK, this is not a scientific comparison between sun tunnel systems, but it is very much real world. Despite Solarspots claims about being brighter (by 70%!!) than a Solatube, this short video demonstrates how wrong they are. Both systems are installed in the same roof pitch just a couple of meters apart, the Solarspot in the kitchen and the Solatube in the dining room.
The Solarspot is actually bigger, at 375mm dia, whereas the Solatube is only 350mm dia, so you'd expect the Solarspot to be brighter. However, it isn't which just goes to show how good a Solatube is.
I've not tried to bias this one way or the other and I've been as fair and honest as possible to give both systems the chance to perform. The sky was overcast so there was always equal daylight levels outside.
The smaller diameter Solatube 290DS delivers at least as much light, if not more, than the larger Solarspot 375mm diameter sun tunnel.
