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What are sun tunnels and which are right for me?

What are sun tunnels

Sun tunnels offer an inexpensive solution for bringing light into a home where there is limited space for a rooflight. They feature a panel that sits discretely on the outside of a roof, a highly reflective tube channelling sunlight into the room, and a diffuser that disperses light naturally.

Sun tunnels are also known as light tunnels, light tubes or sun tubes. They can be installed on flat and pitched roofs, providing a good solution for dark bathrooms, loft spaces or small home offices. They are also beneficial in hallways and corridors, reducing electricity bills by introducing natural sunlight. It pays for itself!

Which sun tunnels are right for me?

Sun tunnels suit such a variety of needs. Accordingly, there are a number of options when it comes to picking which are right for you. The first decision when buying a sun tunnel is whether to choose a flexible or rigid sun tunnel. This will depend on where you’re aiming to direct light and what will it will need to pass through.

Flexible sun tunnels

Flexible sun tunnels incorporate a bent or angled tube, reducing the amount of light that enters a room. However, because of the way that light bounces off the reflective insides of the tube, you can get around any obstructions that prevent you from using a rigid alternative. For example, if your loft space features air conditioning units or services, you can get around these with a flexible sun tunnel.

Flexible sun tunnels are best suited to shorter distances. They allow you to pick the optimum placement on the outside of the roof and direct the tube exactly where you’d like it. You can do this even if that positioning isn’t directly below the roof.

Rigid sun tunnels

Rigid sun tunnels consist of one straight tube to direct light where you need it. These tunnels can’t be bent or angled, but will give you the most light transmission as the light travels in one motion to reach its destination. Rigid sun tunnels are the most common choice for applications where the tube is installed through an empty roof space into rooms below.

What size sun tunnels do I need?

Sun tunnels come in many sizes, made for either slate, tiles or flat roof substrates. To ascertain the correct size of sun tunnel you need, first look at where and why this is being installed. For example, will the light become a design feature, e.g. do you want to install the sun tunnels in an evenly spaced row or in a symmetrical pattern? Do you simply need one sun tunnel to light a small, dark corridor?

For applications where you’re lighting a small room, it is recommended to purchase the biggest product that will fit in the ceiling space. For larger rooms such as spare bedrooms or bathrooms, one or two medium-sized tunnels will be an attractive feature.

Room size Example room types Recommended diameter 
0–4m2 Hallways, larders, walk-in wardrobes and en-suite bathrooms 10 inches
4–10m2 Small rooms, stairwells and home offices 10 inches
11–15m2 Bathrooms and bedrooms 14 inches
16–22m2 Kitchens, living spaces and extensions 14 inches


How much light will sun tunnels provide?

The amount of light a sun tunnel provides is dependent on several factors. This includes whether your roof is south-facing, from which it is possible to generate the most amount of light. If your roof doesn’t face south, this isn’t a problem. Sun tunnels are highly reflective and provide good levels of light all round. Another factor that will determine the amount of light is the shape and size of the room. For example, if you opted for a smaller 10-inch diameter sun tunnel in a 20m2 room, the light dispersion would not be sufficient to light the whole area.

In the ideal south-facing conditions, a rigid sun tunnel of 10 inches will provide around 150–200 watts of dispersed light. Compare this with a 14-inch option, which will generate around 200–250 watts.


What brands of sun tunnel are there?

Many popular brands of sun tunnels are available. Choose between VELUX pitched roof sun tunnels and flat roof sun tunnels, FAKRO pitched roof light tunnels and flat roof light tunnels, as well as Monodraught sunpipes, Em Tube pitched roof skylights and Em Tube flat roof skylights.

For information or guidance, call our team of friendly advisers on 01752 692 760. Alternatively, use the live chat function in the bottom right-hand corner of our website.


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