Frequently asked questions

What is Solarspot® tubing made from?

All Solarspot® systems incorporate Vegalux® 99.7% reflective tubing – anodised aluminium sheets laminated with 3m Daylighting DF2000MA film, the most reflective tubing material in the world – to guarantee optimum light transmittance. In addition, the systems are designed to maintain the maximum available tube diameter within their designated sizes. For example, a Solarspot® 250mm system maintains its diameter throughout the whole system compared to other systems that taper – thus losing valuable energy. This is one reason why a Solarspot® will deliver significantly more light than any other 250mm systems at a distance of around 5m.

How important is the reflectivity value of the tube?

Light travels through the system by bouncing off the reflective sides of the tube. As light travels down a tube it loses energy with every bounce. The amount of energy (light) that is lost will be determined by the reflectivity of the surface of the tube. The number of bounces of light will be determined by the length of the tube, the angle of light as it hits the side of the tube and the length of the tube.

For example, a tube with a reflective surface of around 99.7% (specular refectivity of visible light) will lose 0.3% with every bounce. A tube with a 98% (92% specular reflectivity and 6% diffused reflectivity) reflective surface will lose a minimum of 2% per bounce. You then need to consider the number of bounces that the light takes to reach from one end of the tube to the other. If the light bounces 20 times in the tube and loses 2% per bounce it will have lost around 30% of its original strength. If it is only losing 0.3% then it will retain around 94% of the source light for delivery to the room. This example is based on tube systems with similar lengths and diameters.

However, Solarspot systems have a variety of additional design enhancements to increase the overall efficiency of the system. The Solarspot dome ensures that no light is blocked from entering the system. The RIR® Light Funnel not only captures additional light, it changes the angle that the light enters so that it bounces less, and therefore loses less energy. Solarspot systems also maintain their tube diameters so that there is a greater distance between bounces. All of these factors contribute to creating the most efficient tubular daylight system available on the market today.

How long can the tube be?

The simple rule is; the shorter and straighter the tube, the greater the light delivery will be. However, it is possible to duct light along comparatively long distances, particularly if the building can accommodate a wider tube diameter.

Having said that, a Solarspot® D-25 will still deliver worthwhile light levels across distances of up to 8m. Larger systems such as the Solarspot D-38 can deliver effective light levels up to distances of over 11m.

Larger systems like the Solarspot D-53 and D-65 are able to pipe light for distances up to 18 and 24 meteres respectively. And for really impressive light transfer, there is currently a test project underway where the Solarspot D-90 is being used at a distance of up to 40 meters.

Is there a minimum distance or tube length?

The minimum distance that a tube is likely to be equal to that of the thickness of the roof timbers and depth of the roof, including the turret up stand of the flashing. Solarspot TDS are designed to telescope together to accommodate this and will fit into the any depth of roof.

Can the tube be cut to length?

Yes, it is relatively straight forward to cut Solarspot®extensions to length but rarely is it necessary. Extension tube sections are designed to telescope together for ease of installation so tube length can be adjusted by simply overlapping the tubes as required rather than cutting them.

There is also a wide variety of Solarspot®extensions available; ranging from 200mm to 1200mm, as well as a selection of adjustable angle adaptor extension, so you should be able to specify exactly the distance required.

How do the tube sections connect together?

Solarspot® extension tubes and adjustable angle adapters are designed with a slight taper so that they can be telescoped together. The joints are then held in place with high-quality foil tape, which is also used to seal all of the tube seams. For very long or angled tube lengths, self-tapping screws can be used to fasten the tubes together to give additional strength and stability.

Can I split the light from one dome to light two rooms?

Solarspot® TDSs are designed to use one dome per tube. Splitting the tube would dramatically reduce the light delivery capacity of the system making it problematic and inefficient, and certainly not something we’d recommend, however there are specific applications that this can be done. For example; starting on the roof with a large dome and tube diameter, then splitting into two smaller diameter tube systems.

How do Solarspot® systems compare to tubular skylights that use flexible tubing?

There is no comparison between the light from a Solarspot® rigid TDS and that of even the ‘best’ flexible system. On average a Solarspot® TDS will deliver at around 20 times more light, size-for-size, than a flexible system and if the system has a bend in it (usually why flexible systems are chosen) the difference could be around 50 times more light.

Can I turn the light off?

There will be certain application where you may want to control the amount of light entering a room; a conference room or bedroom are two prime examples. For this situation we have two options to choose from. The first is an electrically controlled damper.

The Solarspot® Solar-Dimmer™ is fitted within the tube and can be controlled via a manual wall-mounted switch, hand-held remote control or BMS.

There is also a manual blind system that simply fits on the ceiling, around the diffuser, and pulled across as required.

Does the system require maintenance or cleaning?

All Solarspot® systems are maintenance free and therefore there is no need to clean the roof dome. The dome design and shape prevents debris build-up using the rain to clean away any dirt or bird droppings.

Can the dome be raised higher to catch the sun on a shady roof?

If necessary, domes can be raised using a turret extension. The turret extension increases the height of the up stand of the roof flashing so that it raises the dome clear of any roof obstructions. Turret extensions are available in various heights – please contact us for details.

Does heavy snow effect the performance of a Solarspot® TDS?

Clearly, a covering of snow will temporarily reduce the light output but the dome will be fine. Solarspot® are sold throughout the world, in countries with much higher snow falls than we experience in the UK and so are designed to cope with whatever the weather has in store.

What is the dome made of?

All Solarspot® domes can be supplied in anti-shock acrylic and designed not to turn yellow when exposed to sunlight. The dome is virtually unbreakable and has passed stringent international missile impact tests. To comply with UK fire regulations, all Solarspot systems are fitted with a fire-rated polycarbonate inner lens. The ‘Convas lens also provides a secondary glazing layer to further increase the thermal efficiency of the system.

Can a Solarspot® be adapted for night time use?

Light kits are available for all sizes of Solarspot® systems. These can be installed into the tube to utilise the highly efficient diffuser and minimise ceiling clutter.

For installation where a minimum light levels needs to be maintained, the Solarspot LED inteltegent lighting solution can be used. Each Solarspot daylight system is fitted with a responsive LED light system that automatically ctus in when there is insufficient extenal light livels to provide the required internal lux levels.

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Will an electric light kit reduce the amount of daylight from Solarspot?

The lamp unit inside the tube is relatively small so any light loss is minimal. The advantage in having just one neat ceiling installation yet having a two-in-one or three-in-one multi-functional.