Highly efficient thermally broken aluminium bifold doors - available with double or triple glazing
Manufacturers recommend panel widths do not exceed 1,100mm, with a maximum height of 3,500mm.
The system can cater for very large openings - up to seven metres in any one direction.
The SF75 bifold door profile is constructed from a strong aluminium extrusion. This has been thermally broken by a 44mm polyamide insulation bar, guaranteeing it maximum resistance to combat heat loss and condensation. The minimal framework is offered as a square edge profile.
There are two choices of track; a standard weathered track for a severe weather rated system and a low threshold track. The low threshold track complies with Building Regulations Document M for disabled access.
In any exposed location we would always recommend the use of a weathered track. When used with an outward opening door a weathered track can be fully recessed below your internal floor level meaning that there is no threshold to trip over, just a 35mm step down to the outside. An external deck or paving can be brought up to the track on the outside giving a very minimal difference in levels whilst maintaining a weather tight seal.
Low threshold track
The Low threshold track can be recessed into the floor with matching inside and outside floor levels and just a small 14mm upstand on the track. The upstand allows the doors to form a seal, whilst offering a smaller difference in floor level than the weathered track.
Lead door or single pass door fitted as standard with a five-lever key-locking cylinder, incorporating mushroom headed ESPAG bolt and shootbolts top and bottom. A central latch position can be added for convenience with a horizontal stainless steel lever handle. First opening pair consists of a two-point top and bottom shootbolt mechanism. The locking system is incorporated within the framework within each intermediate panel, operated by an internal flush handle.
For improved security, all SUNFLEX bifold door systems are internally glazed as standard, with centre secured locking hinge pins and interlocking gaskets.
Where there are an odd number of panels, a five-lever profile cylinder is fitted to the end lead door or to the first opening pair in an even number of panels. It can be fitted to either the inside only or both internally and externally, meeting the requirements of the Association of British Insurers.
The shootbolt rods are manufactured in aluminium and linked by a corrosion resistant cam. In addition they are capped with polyamide cones that prevent any damage to the track when locking, whilst compressing the panels tight against the top and bottom seals.
Throughout the range of SUNFLEX bifold door systems you have the option of internal and/or external handles. Handles are fitted to every intermediate door panel and additional locks can be added at these points for higher security.
There are further enhanced security options available and panic locks can be fitted for fire escapes, etc. SUNFLEX also offers electric latch-release locks and a rollerball latch lock for commercial use.
The system is a severe weather rated system when used with the weathered track option, providing a top and bottom double-rebated seal. Unique triple gaskets provide a finger cushion and eliminate draughts. The system achieves BS EN 12207 air permeability Class 4, water tightness Class 9A (900Pa), wind resistance Class 4.
The stainless steel running mechanism consists of four wheels, manufactured from tough glass fibre reinforced polyamide. And set around a maintenance-free sealed ball-bearing, giving a quiet, smooth operation with optimum resistance to extreme weather and temperatures fluctuations.
The SF75 bifold door can be adjusted to alter height and load of the system to provide a degree of tolerance. The wheels of the running mechanism run in a channel in the sides of the track rather than sitting directly on the bottom. Unlike many inferior systems, this minimises the risk of the operating system fouling, should any dirt or debris be allowed to build up in the bottom of the track.
The unique design of running gear mechanism hinged between the door panels eliminates the need for a sliding post. This achieves smoother operation, slim sightlines and larger glass area.
The SF75 system is available as standard in silver anodised EV1 or polyester powder coated to a semi-gloss finish - white RAL 9016; aluminium RAL 9006; grey aluminium RAL 9007; or anthracite grey RAL 7016.
Single doors fitted as standard with stainless steel lever handles. With first opening pair and intermediate door panels fitted with flush handles are specially designed to complement the door system. Standard colours are white RAL 9016; black RAL 9011; aluminium RAL 9006; grey aluminium RAL 9007; or anthracite grey RAL 7016. Gaskets are in black, with hinges mounted within seal sightline available in white RAL 9016 or black RAL 9011.
Other RAL colours are available with over 200 colours to choose from. You can even have different colours to the inside and outside (dual colour) or different wood grain effects are available for a nominal charge. The RAL colours can be applied to the handles and hinges if required or alternatively there is a stainless steel handle and hinge option. In addition you can specify whether a matt, semi-gloss or full-gloss level of paint finish is required.
A marine environment finish, required to all systems within 5,000m of a shoreline or chemical swimming pool environment, is also available.
Trickle vents with an airflow equivalent to 2,500mm2 or 5,000mm2 can also be incorporated with the addition of a 35mm add-on head profile. These will be colour coded to suit the frame colour choice.
In the situation of a single access or pass door in an odd number configuration, the panel is fitted with a panel catch. This prevents the door from swinging back around in high winds, and also counter weights the door with the adjacent panel for effortless operation.
When the bifolding door system opens externally the intermediate panels are fitted with a moulded 'D' shaped handle. This is attached to the internal hinge between two even panels, and sits neatly within the gasket line. This enables easy closure of panels against the compression top and bottom gasket seal.
The SF75 bifolding door system is internally glazed and can accommodate triple glazing with a sealed unit of up to 56mm.
Our standard comprises of a 4mm triple glazed 48mm unit with a centre pane U-Value of 0.6W/m2K clear toughened glass to exceed all building regulations for safety and thermal efficiency.
All units are BS kite marked, manufactured to BS EN 12600 and BS 5713:1979 standards.
IDSystems offer a wide choice of glazing options, including manual or electrical internal venetian or pleated blinds which can be incorporated inside the glazed unit (depending upon glass specification). These are very popular, especially on internally opening systems where curtains are not practical.
U-Values and heat losses
A U-Value is a calculation of the amount of heat lost through a building material. The calculation of U-Values can be quite complex as it is measured as the amount of heat loss through a 1m2 of material for every degree difference in temperature either side of the material. It is indicated in units of watts per square metre per degree Kelvin or W/m2K. The simplest way to approach U-Values is the lower the U-Value the more thermally efficient a product is.
A U-Value of a door or window is calculated by working out by determining the U-Value of the frame and the area of the glass and is then quoted as an overall U-Value. Beware that some manufacturers may just be providing the U-Value of the glass alone which gives a false overall value. All of our systems have been thermally simulated in accordance with CE standards to BS EN ISO 10077.
Building Regulations approval will be required on all extensions and new builds to which we are able to provide CE data showing compliance. Any replacement works we are able to cover being a member of FENSA and a certificate would be provided on completion of our installation.
Double or triple glazing
Double glazing is a minimum requirement for external doors and windows. Our standard double glazed units consist of a soft-coat Low-E (low emissivity) pane and an argon gas filled cavity which provides a centre pane U-Value of 1.2W/m2K. Over the standard we can provide super insulated double glazed units providing a centre pane U-Value of 1.0W/m2K whilst providing solar control.
Triple glazing is becoming increasingly popular, especially in total new builds, as it provides the lowest U-Values possible and can be up to 40% more efficient than double glazing. Combining two panes of Low-E glass and two gas filled cavities glazing U-Values as low as 0.5W/m2K are possible with the added benefit of great sound reduction.
For more information on our huge range of glazing options or for help in specifying the correct glass for your project contact our technical sales department on 01603 408804.
Solar control and the benefits of solar gain
With the standard glass specification retaining as much heat as possible you may wish to consider reducing the heat transfer from outside which is known as solar gain. Solar gain can make glass roofs, conservatories or south facing elevations quite uncomfortable in the height of summer months.
A solar control glass is a glass with a either a special coating or a body tint to reduce the amount of heat entering a building either by reflecting or absorbing heat. Using a solar control glass can reduce the need for air conditioning and blinds. Whilst the solar control glasses are great at reducing the heat they will also reduce light transmittance.
Building control often recognise the benefits of solar gain in modern buildings as large areas of glass will work as a source of free energy during cooler months and increased solar gains are recommended. The use of low-iron glass can increase the heat and light transmittance to provide further solar gains during the autumn and winter months. Many modern designs incorporate overhangs to cast shadows over glazing during the summer combatting the solar gains. Thus allowing solar gains as the sun gets lower in the sky later in the year reducing the need for heating.
When required we fit toughened glass to comply with Building Regulations Document N as an alternate method of compliance we are able to fit laminated glass. Both options have their pros and cons.
Toughened glass has been heat tempered to increasing its strength over ordinary annealed glass by up to five times. Other than the strength the advantage of toughened glass is that should it break it would shatter into non-sharp pieces. It is also available with the widest variety of coatings and can be supplied in larger sheets than equivalent thickness laminated glass.
When the glass is toughened it can suffer from some visual distortion making, meaning the face of the glass is not perfectly flat distorting some reflections.
Laminated glass is manufactured by bonding two panes of annealed glass with a clear plastic interlayer. The benefit of laminated glass is that if it’s broken the glass will crack rather than shattering, improving security. In addition, laminated glass reduces bleaching of carpets, curtains and furniture by filtering UV rays that would usually penetrate the glass.
The drawback of laminated glass is that extreme heat or cold can cause invisible defects in the glass to form a crack due to the two panes expanding and contracting independently. As the laminated glass is not toughened is does not suffer from the visual distortion that can occur to toughened glass during the toughening process.
As well as offering full height clear glass we can also provide a more traditional style of glazing by incorporating glazing bars, Georgian grids or lead work. Please contact us for further information.
Often neglected when planning your new build or extension is where a suitable space may be for your feline friend, we have the ideal solution. It is possible to have a cat flap fitted into a glazed panel by cutting a circular hole into the toughened glass unit for you to fit an in-glazed cat flap.
We are able to fit venetian blinds within the glazed unit, ensuring a totally dust-free environment which requires no cleaning or maintenance. These are very popular, especially on internally opening systems where curtains are not practical.
Integrated blinds can be tilted to help prevent the build-up of excessive heat and glare of the sun during the daytime and provide privacy when closed. Blind units can be manually operated with an ingenious magnetic control device or electronically operated via remote control. Please visit our dedicated blinds pages for further information.