Frequently asked questions about sun tunnels

Intura combines durable materials with measurable daylight and thermal performance. SunTube25 and SunTube35 use a crystal-glass dome, while the roof systems use a double-walled insulated aluminium upstand, a rigid 99.8% reflective tube and pre-installed roofing material. EcoPower can reduce the calculated U-value of the complete system to between 0.65 and 0.94 W/m²K, depending on diameter and glazing.

Crystal glass does not yellow through UV exposure and retains its clarity over time. Its hard, smooth surface resists weathering and dirt, and rain on glass generally creates less drumming noise than rain on a thin plastic dome. Intura uses crystal glass on SunTube25 and SunTube35; SunTube55 uses a PMMA dome.

The double-walled aluminium upstand provides a rigid and durable roof connection. Its insulated construction is thermally more considered than an uninsulated roof interface, while the RAL 9005 finish provides a consistent exterior appearance. Correct integration with the roof insulation and airtight layer remains essential.

For flat roofs, the selected bitumen, EPDM or PVC roofing material is already fitted to the upstand. Pitched-roof versions use a pre-installed Leadax connection. This reduces separate preparation on site, helps the roofer match the system to the existing roof covering and supports a fast, clear route to a watertight installation.

EcoPower surrounds the tube with 14 cm of PIR insulation and adds an airtight double- or triple-glazed barrier. Depending on diameter, the calculated U-value of the complete SunTube improves from 2.44–2.70 W/m²K without EcoPower to 0.91–0.94 W/m²K with HR++ or 0.65–0.70 W/m²K with HR+++. This represents about 62–66% or 71–76% less calculated heat transfer respectively.

Yes. The system combines durable exterior materials, a rigid aluminium mirror tube, insulated roof components, optional accessories and documented technical performance. Installation manuals plus PDF and CAD drawings support use by roofers, contractors, architects and other building professionals.

A sun tunnel is a daylighting system that carries natural light from a roof or exterior wall into an interior room. The Intura SunTube uses a roof dome, a highly reflective rigid tube and a ceiling diffuser to spread soft daylight through the room.

Yes. Sun tunnel, sun pipe, light tube, light tunnel and tubular skylight are common names for the same type of tubular daylighting system. SunTube is Intura's product name.

The exterior dome collects daylight. A rigid mirror-finish tube then transports the light through the roof or wall, and an EasyClick diffuser distributes it evenly inside. It provides daylight without using electricity.

The rigid aluminium mirror tube is 0.5 mm thick and has a light reflectance of 99.8%. The standard tube section is 60 cm long, can be shortened on site and can be extended with additional tube sections.

Yes. A SunTube still collects and transports diffuse daylight when the sky is overcast. The amount of light varies with the weather, season, tube length, number of bends, roof orientation and chosen diameter.

Sun tunnels are well suited to hallways, bathrooms, kitchens, stairwells, utility rooms, home offices, bedrooms and other spaces where a conventional window or rooflight is not practical. They can also be used in commercial buildings such as offices, schools and retail spaces.

A rooflight brings daylight directly through a relatively large roof opening into the room below. A sun tunnel uses a compact reflective tube, so it can carry daylight around roof-space obstacles and into rooms that are not positioned directly beneath the exterior dome.

SunTube25 and SunTube35 use a crystal-glass dome. Glass does not yellow through UV exposure, retains its clarity, resists weathering and dirt, and generally creates less drumming noise in rain than a thin plastic dome. The larger SunTube55 uses a PMMA dome.

As a guide, SunTube25 is suited to smaller rooms of up to about 9 m², SunTube35 to spaces of roughly 13–16 m², and SunTube55 to larger areas of around 25–30 m². Actual daylight levels depend on the building, tube route and local conditions, so ask Intura for project advice when in doubt.

There is no single fixed lumen figure because output changes with daylight, season, orientation, shading, tube length, bends, ceiling height and interior colours. Under favourable conditions, SunTube35 can provide approximately 900–1,300 lux in summer and 400–700 lux in winter, measured 1.5 metres below the diffuser. These figures are an indication, not a guarantee for every project.

Several systems can produce a more even spread of daylight across a large room. For offices, schools, workshops and warehouses, the diameter, number, spacing, ceiling height and required light level should be considered together in a daylight plan.

Yes. The flat-roof SunTube has an insulated, double-walled aluminium upstand. It is available with pre-installed bitumen, EPDM or PVC roofing material for a faster and more secure roof installation.

Yes. The pitched-roof SunTube uses an insulated upstand with a Leadax flashing. The best location and detailing depend on the roof covering, pitch and internal tube route.

Yes. The Intura SideLight system carries daylight horizontally through a facade or wall. It is useful for basements, cellars, extensions and windowless rooms where roof access is limited or unavailable. Daylight output depends on facade orientation, surrounding obstructions and the tube route.

The optional EcoPower insulation element improves the thermal performance of a SunTube. It combines 14 cm of UNILIN PIR insulation with an Rd value of 6.30 m²K/W and an airtight insulating glass barrier. The HR++ version uses double glazing with Ug 1.1 W/m²K; the HR+++ version uses triple glazing with Ug 0.6 W/m²K. Both are available for SunTube25, SunTube35 and SunTube55.

Every roof penetration needs correct insulation and airtight detailing. Calculated U-values for the complete standard SunTube are 2.44 W/m²K for ST25, 2.63 for ST35 and 2.70 for ST55. With EcoPower HR++, these improve to 0.93, 0.94 and 0.91 W/m²K—about 62–66% less calculated heat transfer. With EcoPower HR+++, they improve to 0.70, 0.69 and 0.65 W/m²K—about 71–76% less. EcoPower also raises the internal surface temperature and helps reduce condensation risk, but careful installation remains essential.

A standard complete set includes the exterior dome, an insulated aluminium upstand or wall box in RAL 9005, one 60 cm mirror tube, an EasyClick ceiling diffuser, and the required installation materials. The exact components vary by roof or wall configuration, so check the chosen product page before ordering.

The rigid tube can be extended up to approximately 6 metres using additional 60 cm mirror-tube sections. A shorter, straighter route normally provides more daylight than a long route with several bends.

Yes. Adjustable elbows of up to 45 degrees can route the mirror tube around structural elements. Keep the route as short and straight as practical because every bend and extra tube section can reduce daylight output.

A tube route can be built up to approximately 6 metres and may pass through more than one level, subject to the building design. Long routes and bends reduce output, so the diameter and route should be assessed in advance and all structural, fire-safety and Building Regulations requirements must be checked.

Yes. An optional dimmer can restrict the natural daylight when a darker room is required. An optional LED module allows the same ceiling position to provide electric light after dark or when there is insufficient daylight. Electrical components must be planned before installation and connected in accordance with applicable regulations.

Confirm the roof type and roof covering, choose the exterior-unit position, measure the full distance to the finished ceiling, and check for joists, pipes, cables and other obstacles. Then choose the diameter, extension tubes, elbows, EcoPower option, dimmer and any LED module. For specification advice, send Intura photographs and a section drawing with the main dimensions.

An experienced installer or competent roofer should normally fit the system. Correct roof detailing, weatherproofing, airtightness and safe working at height are essential. Intura provides installation manuals and can help you find suitable technical support.

Visit the technical support page for installation manuals plus PDF and CAD drawings for flat-roof, pitched-roof and side-wall SunTube systems.

Requirements depend on the property, location and scope of work. Listed buildings, conservation areas and some structural or fire-safety situations can need specific consent. Check with your local planning authority, building control body or project professional before installation.

Yes. Complete kits, extension tubes, elbows and EcoPower insulation elements are available in the Intura UK online shop. Choose the correct diameter, installation type and roof covering before ordering.

Many standard products are shown with UK shipping in 2–3 business days. Availability and delivery times can vary by product, quantity and destination, so check the current product page or order confirmation for the applicable delivery date.

Yes. Intura supports homeowners, roofers, contractors and specifiers with product selection, tube routing and technical documentation. Use the contact form, email justin@intura.co.uk or call +44 1932 731759.