There is no universal door configuration, and no one surface-mounted door closer will fit every door configuration without modification. For this reason, most manufacturers of surface-mounted door closers offer a number of models that can be ordered with different options and accessories.
Note: Door closer manufacturers use some of their own spellings and words for component terminology. For this reason, I will attempt to use the most common terminology where possible.
Although I would not consider the spring power an accessory or option, the first consideration when ordering a door closer, surface-mounted or not, is to know the door size, approximate weight or application and the features required for the installation. Door closer features can include delayed action and adjustable spring power.
Few modern surface-mounted door closers are handed. An example of a handed surface mounted door closer is a “pot” style of door closer which was invented more than 100 years ago.
Double Lever & Single Lever Arms
There are two basic arms for most surface-mounted door closers: the double lever arm and the single lever arm. The double lever two-part arm is installed onto stop side (Push Side) of the door in either top jamb or parallel arm mountings. It is installed onto the hinge side (Pull Side) of the door using the regular arm mounting. The Regular Arm and Top Jamb applications allow the door to open to about 180 degrees, depending upon the configuration of the opening. Standard Parallel Arm applications allow the door to open to about 110 degrees. The geometry of the double lever arm provides greater mechanical advantage to the closer.
The double lever arm is made up of the main arm and the fore arm hinged at the elbow. The main arm attaches the closer spindle to the fore arm. The fore arm connects the main arm to the attachment point on the door or the jamb. Depending upon the mounting, the fore arm can be attached to a shoe (foot), soffit, soffit plate or soffit shoe.
Some shoes/feet have a second or third connecting (pivot) point for the fore arm. These additional connecting points can increase or decrease the closer power by altering the shoe (foot) pivot angle. A tighter angle increases the spring closing power.
The single lever arm is the track style arm, which is a combination of a main arm and a rectangular box. The arm slides from end towards end as the door closes. Track arm closers are normally used on interior or sheltered exterior doors. This application allows the door to open to about 110 degrees on either the pull or push side, depending upon the configuration of the opening.
Types of Arms
Probably the widest array of choices for a surface-mounted door closer option is the type of arm. Most of these door closers come with a standard duty double lever arm and shoe (soffit) that will accommodate regular arm, top jamb and parallel arm mountings.
The most common arm option is probably the Hold Open Arm, which enables the door to be swung open to a point in the swing of the door and to remain open in that position until the door is physically released. Usually the purpose of the hold open arm is to permit access and egress without having to open the door.
The holding open is achieved by means of friction, a series of set positions that hold the door open at specific degrees of opening or a control handle mechanism. A friction hold open can have an open range of less than 90 degrees to more than 180 degrees depending upon the installation. For example, the Norton ball and detent or roller hold open arm has an effective range of 85 to 110 degrees.
IMPORTANT: Hold open arm equipped door closers are not permitted to be used on fire door openings.
Then, there are a variety of arms including heavy duty, spring arms, positive stop arms, cushioning arms, extended arm rod, fusible link arms, offset brackets, etc.
The heavy duty arm is designed to provide additional strength and mass, ensuring a more solid connection between the door and the jamb or wall.
Determining exactly what the end-user needs and installing the best door closer with the appropriate arm and options will give your customer many years of trouble free operation.