Light Calculation
How much light will I get from my Sky Tunnel?
Tests carried out in the UK (by Durham University) prove that anything up to twelve times the equivalent of a 100 watt light bulb can be achieved with 3 metres of Flexi-tube run on the 550mm diameter unit.
As with all natural light providers this depends on the exposure to the available daylight (south facing is best) also the length of Flexi-tube, time of day, time of year etc. The larger diameter Sky Tunnel installed the more volume of light will be transmitted.
The location of the roof dome should be directly above or as near as possible to the ceiling diffuser. The roof dome assembly should be installed as near as possible to the ridge. Avoid bends in the Flexi-tube, as this will affect efficient light transmission. Ideally the Flexi-tube should be configured as shown in the diagram opposite.
We recommend a roof specialist fit the Sky Tunnel should it be necessary to make alterations to the rafters and joists.
Other factors should also be considered i.e. colour scheme of interior and on which elevation the roof dome is going to be positioned; south, east, west, also the length of tube. The tables on the right are an indication only.

Sky Tunnel Flexi Tube
| 343mm (diameter) | 457mm (diameter) | 535mm (diameter) |
|---|---|---|
| Ensuite WC Walk-in-robe 2m x 2m |
Bathroom Hallway Small Landing 3.5m x 3.5m |
Living areas Large Landings Kitchen 5m x 5m |
Sky Tunnel Rigid Tube
| 343mm (diameter) | 457mm (diameter) | 535mm (diameter) |
|---|---|---|
| Bathroom Hallway Small Landing 3m x 3m |
Bathroom Landing Office Corridors 4.5m x 4.5m |
Commercial Areas Corridors Offices, Retail Areas 6m x 6m |




