One of the features of virtually all commercial aluminium doors is that they are fitted with some form of door control and door closing device. Unlike residential doors which are free swinging and rely on their hinges, most Commercial Aluminium Doors will have a self closing device in the form of either a face fixed or concealed overhead door closer. But what are these and how do they aid the use and function of a commercial door?
What is the difference between a face fixed and a concealed closer?
A concealed closer you will find fitted to most commercial aluminium doors. It is not visible as it is mounted in the overhead frame and hidden. Face fixed closers on the other hand look like “traditional” door closers in that they are fitted to the outer frame and door leaf, either on the inside or outside.
The concealed closer has several benefits over a face fixed door closer. Commercial doors fitted with these types of closers can open in or out as well as in and out. Fitted to a non rebated frame, a simple door stop that can be reversed or removed if required enables much more flexible door control.
Face Fixed Closers are also known as pinion closers and are always fitted to doors that have a rebated. This means they can only open in or out and therefore the building owner/specifier must be sure which direction they wish their doors to open.
What are cam action door closers?
Cam Action closers differ slightly from the traditional “scissor arm” of rack and pinion closers. They slide within an integrated arm and channel and are far less obtrusive. Another advantage of cam action closers is that they can help achieve requirements of current building regulations such as Approved Document M and BS8300. quirements of ADM and BS8300* compliance within a greater tolerance than traditional rack and pinion door closers. This is particularly important as hinges and intumescent seals will provide additional resistance to opening and closing. Because cam action closers use slide arms they are far less visible and with no visible fixings. This makes them less prone to vandalism or abuse.
What is Backcheck?
Most high quality commercial door closers and whether face fixed or concealed should come with backcheck as standard. Backcheck ensures that a door remains under control of the closer should it be forced or aggressively opened. Imagine a door without a closer that is kicked open – quite likely it will get damaged on its hinges and damage any adjacent wall. Backcheck prevents this happening.
One huge advantage of backcheck is the protection it offers to internal finishes and how it can reduce maintenance and building repair costs through abuse of the doors which can occur in heavy usage installations such as schools.
What is Delayed Action?
This allows the door to stay open longer and a greater number of people to go through the door before it begins to close.With delayed action, the door is opened and then delays for a set period of time before closing.The delay is adjustable by valve and can be adjusted to suit each application.
This for example would be useful on a classroom door allowing all of the occupants who would be accessing the door at the same time to either enter or leave the room with just one opening and closing cycle of the door.When this is compared to 20 or 30 individual operations, it would lead to a significant reduction in the life cycle basis.