Selecting a Door Closer

/Local/AU/OWNA%20Images/720-Door-Closer.jpg

Selection of door closer size is judged in two ways.

  1. Does the door closer have the strength to effectively close the door against unexpected air pressures?

  2. Is the door closer oversize for the application and therefore affecting the ease of operation?

Efficiency of the door closer also has a major bearing on ease of operation. For optimum performance it is essential that a highly efficient door closer of a correct size is selected.

The use of spring strength adjustability, which allows fine tuning of strength on site, has simplified this task but not removed all of the guesswork. With more architects and engineers becoming conscious of the problems caused by incorrect selection of door closer strength, it has become the responsibility of manufacturers to provide better technical information, such as closing torque and efficiency of their products. The following chart has been produced to cover most conditions. If you have an unusual application which you feel requires special consideration, please forward all relevant information to your local office and we will be happy to advise the best door control for your application.

Fire doors and pressurised stairwells pose significant challenges in ensuring closing and latching of fire doors. The problems are created by differential air pressures resulting from airconditioning systems, either on one or the other side of the door. To achieve complete fire safety, fire doors must latch securely at all times. If this performance is not achieved, the stairwell may be unsafe, and in the event of fire, loss of life and property may occur. Correct selection of door hardware is of paramount importance in ensuring that the appropriate operating standards are met.

Fire doors which open into a pressurised stairwell must meet the following criteria:

  • the door must close against a pressure differential between the airconditioned floor area and non-airconditioned stairwell;
  • the door must latch securely every time it closes;
  • the door must be able to be opened with a force not exceeding 110N when the stairwell is pressurised; and
  • the door must be protected from damage when it is opened by means of a backcheck action which is built into the door closer.

Notes:

  • Always round up to the next door width (ie for 870 mm door use 950 mm).
  • If parallel arm installation, then use next door width door line (ie, for 830 mm door use 950 mm).
  • For internal doors deduct 200 mm from actual door width (ie for 1250 mm internal door use 1050 line).
  • This chart is based on normal climatic conditions (ie pressure differential of 30Pa or wind of 15 knots).
  • If more severe conditions are expected then use the next door width.
  • When specifying parallel arm and slide rail functions, allowance should be made for the following power loss:

Parallel Arm Mounting
Approximately 20% power loss
(7700/3024/2024 Series Rack and Pinion Range)

Slide Rail Mounting
Approximately 30% power loss
 (7700/3024/2024 Series Rack and Pinion Range)

Power Selection Chart

This chart will be most useful in selecting the correct door closer. Simply identify the dimensions of the appropriate door and select the recommended door closer.

The chart is intended as a guide only and as such the following variations should be taken into account when making your selection:

  • Environmental factors such as the effect of wind or airconditioning pressures.
  • An unsheltered external door is a door on which prevailing wind gusts will directly produce a “sail area” affect.
  • A sheltered external door is a door way which is protected by a wind break or wall, which acts as a barrier against direct wind gusts.
Recommended Door Width
Door Weight (kg) Max
Closer PowerSize
ClosingTorque (Nm)
750
20
1
9 - <13
850
40
2
13 - <18
950
60
3
18 - <26
1100
80
4
26 - <37
1250
100
5
37 - <54
1400
120
6
54 - <87
1600
160
7
87 - <140