Some accessible panes may be suitable for competent installation using the correct tools and instructions. Professional fitting is recommended for large panes, commercial glazing, coated glass and projects where consistent performance is important.
Thermal insulating window film is designed to improve the performance of suitable glazing year-round. During colder periods, Low-E film helps reflect radiant heat towards the interior. During warmer weather, it can also reduce a proportion of solar heat and ultraviolet transmission entering through the glass.
At Window Films Direct, we supply professional-grade thermal insulation films for trade installers, contractors and commercial glazing projects throughout the UK. Our Low-E products provide a practical way to upgrade existing windows without the disruption and cost of replacing the glazing.
Whether the priority is improving winter comfort, reducing summer overheating or supporting wider energy-efficiency measures, thermal insulating window film can provide a flexible solution for residential and commercial buildings.
Low-E stands for low emissivity.
Low-E window film contains specialist layers designed to reduce radiant heat transfer through the glazing. During colder conditions, the film reflects a proportion of internal radiant heat back towards the room rather than allowing it to pass as readily through the glass.
Selected products can also help manage solar energy entering the building during summer.
Depending on the film selected, potential benefits include:
The precise result will depend on the film, glazing, building and installation.
Radiant heat naturally moves from warmer surfaces towards colder ones.
During winter, windows can allow a significant amount of indoor heat to escape. Low-E film is designed to reduce this transfer by reflecting a proportion of radiant heat back into the occupied space.
This may help:
The film does not create heat or replace insulation elsewhere in the building. It should be considered as one part of a wider energy-efficiency strategy.
Selected thermal films can also reduce some of the solar energy passing through the glazing.
This may help lower:
The level of summer solar control varies between products. A film with strong winter insulation performance will not necessarily provide the highest summer heat rejection, so the individual technical specification should be checked.
Low-E 20 is designed to provide thermal insulation alongside solar-control performance.
It may be suitable for buildings where the priority is to improve heat retention during colder periods while also reducing some summer heat and UV transmission.
Typical applications include:
The precise balance of light transmission, heat retention and solar rejection should be confirmed from the product data.
Cold glazing can create uncomfortable areas close to windows.
Low-E film may help increase comfort by reducing radiant heat loss and improving the perceived temperature near the glass.
Selected products can reduce solar heat entering during warmer periods.
This may help keep rooms more comfortable without permanently closing blinds or curtains.
Thermal film allows useful levels of visible light to pass through the glazing.
The amount retained depends on the product, tint and construction.
Many Low-E films also reduce a high proportion of ultraviolet transmission.
This may help slow fading affecting:
UV radiation is only one cause of fading, so film cannot prevent all deterioration.
Thermal film can be applied to suitable existing glass without removing the windows.
This can make it a practical option where glazing replacement would be costly, disruptive or unnecessary.
Low-E film may help reduce heating and cooling demand by improving the performance of suitable glazing.
Any potential saving will depend on:
Energy savings should not be treated as guaranteed without a project-specific assessment.
Thermal insulating film can be used in residential rooms affected by cold glazing, heat loss or excessive summer sunlight.
Typical applications include:
The selected film should balance thermal performance with the desired level of natural light and appearance.
Commercial properties with extensive glazing may experience uncomfortable heat loss during winter and excessive solar gain in summer.
Suitable applications include:
Thermal film can support building-improvement programmes without the disruption of replacing large areas of glazing.
A compatible Low-E film may help improve comfort in a conservatory by reducing radiant heat loss during colder periods and managing a proportion of solar gain during warmer weather.
Compatibility should be checked carefully for:
A dedicated conservatory roof or external solar-control film may be more appropriate for some roof constructions.
Low-E film may increase the temperature of the internal glass surface in some conditions.
This can help reduce the likelihood of condensation forming, but it will not solve condensation caused by:
Any persistent condensation problem should be assessed separately.
Thermal and solar-control films can overlap, but their priorities differ.
Primarily designed to:
Primarily designed to:
Where both winter insulation and strong summer heat rejection are required, the technical data should be compared carefully.
Not every Low-E film is suitable for every glazing system.
Compatibility should be checked for:
The position of any existing coating within a double-glazed unit can affect film selection.
Incorrect film choice may increase thermal stress or provide limited benefit, so the glazing should be identified before installation.
Most adhesive-backed thermal films use a wet-application method.
A typical installation involves:
Professional installation is recommended for large panes, commercial buildings, coated glazing and projects where consistent thermal and optical performance is important.
Allow the film to cure fully before cleaning.
Use:
Avoid:
Correct maintenance will help preserve the appearance and performance of the film.
The lifespan depends on:
A correctly installed professional-grade internal film can provide many years of service.
The individual warranty and technical information should be checked for more precise guidance.
Browse our thermal insulating and Low-E window films for residential and commercial glazing projects.
Products are available in trade-friendly formats, including by-the-metre ordering and complete rolls where shown. Check the film width, minimum quantity, visible-light transmission, thermal performance, solar performance and glass compatibility before ordering.
For help determining whether Low-E 20 is suitable for a particular glazing system or building, contact the Window Films Direct team for product guidance.
Some accessible panes may be suitable for competent installation using the correct tools and instructions. Professional fitting is recommended for large panes, commercial glazing, coated glass and projects where consistent performance is important.
A compatible Low-E film may be used on some conservatory glazing to improve thermal comfort. Suitability must be checked carefully for double glazing, coated glass, roof panels and specialist glazing systems.
By reducing ultraviolet transmission and some solar energy, suitable film may help slow fading of furniture, flooring, fabrics and displays. It cannot prevent all fading because visible light, heat and material sensitivity also contribute.
Thermal film may help reduce heating or cooling demand by improving the performance of suitable glazing. Any saving depends on the building, glass, film, energy use and installation, so it should not be treated as guaranteed.
Many Low-E and solar-control films reduce a high proportion of ultraviolet transmission. The exact figure should be confirmed from the technical data for the selected film.
Selected Low-E films can also reduce a proportion of solar heat entering through the glass during warmer weather. The precise summer performance should be confirmed from the individual product specification.
Thermal film may increase the internal glass surface temperature in some conditions, which can help reduce the likelihood of condensation. It will not resolve underlying ventilation, humidity or building-fabric problems.
Low-E film is designed to reflect a proportion of radiant heat back towards the room rather than allowing it to pass as readily through the glazing. The result depends on the film, glass construction, installation and building conditions.