Commercial Door Closers: How to Choose Size, Function and Mounting

A commercial door closer can look like a relatively simple piece of hardware, but selecting the wrong model can create ongoing problems: doors that fail to latch, doors that are unnecessarily difficult to open, damaged closer arms, poor access-control operation and, in some applications, problems with fire or smoke-door performance.

Good commercial door closer selection starts with the complete opening rather than simply matching a closer to the approximate weight of the door.

Installers should consider the door width and weight, whether it is internal or external, wind and pressure conditions, mounting position, required opening angle, fire-door requirements, accessibility, locking hardware and the functions the closer needs to provide.

This guide explains the main factors to check when selecting and installing commercial door closers in New Zealand.

Start with the door, not the closer

Before selecting a closer, record the basic characteristics of the opening:

• door leaf width
• approximate door weight
• timber, aluminium, steel or glass construction
• internal or external location
• inward or outward opening
• door handing
• available top-rail and frame space
• required maximum opening angle
• fire or smoke-control rating
• accessibility requirements
• latching or access-control hardware
• exposure to wind or pressure differences
• frequency of use

A lightweight internal office door and a wide external aluminium entrance door may be similar in height, but the demands placed on their closers are completely different.

For this reason, door width alone should be treated as a starting point rather than the only selection criterion.

Understanding door closer power sizes

Many commercial door closers use the EN 1154 power-size system. The higher the size, the greater the closing force available.

EN power size	Recommended maximum door width	Indicative door weight
EN 1	750 mm	20 kg
EN 2	850 mm	40 kg
EN 3	950 mm	60 kg
EN 4	1100 mm	80 kg
EN 5	1250 mm	100 kg
EN 6	1400 mm	120 kg
EN 7	1600 mm	160 kg

These figures are useful selection guidance, but installers should always check the manufacturer's data for the specific closer and mounting configuration being installed.

Wind loading, seals, hinges, air pressure, latch resistance and the mounting method can all affect the actual closing force required.

Fixed-power versus adjustable-power closers

A fixed-power closer provides a predetermined level of spring force. It can work well where the door conditions are known and unlikely to change.

For commercial work, an adjustable-power door closer often gives the installer more flexibility.

For example, a closer rated EN 2–4 or EN 3–6 can normally be adjusted within its specified range to suit different door widths and site conditions.

This can be particularly useful where the installer needs enough force to achieve reliable latching without making the door unnecessarily difficult for users to open.

Essential Security Supplies carries commercial closer options including adjustable models from Lockwood, Briton, dormakaba and ISEO in its Door Closers collection.

Do not automatically select the strongest closer

More closing force is not automatically better.

An excessively powerful closer can make the door difficult to operate, particularly for children, older users and people with reduced mobility. It can also increase loading on hinges, fixings and the door structure.

The objective is to achieve enough closing force for the door to close and latch reliably while keeping opening resistance as low as reasonably practical.

Closing speed and latching speed

A quality commercial closer normally provides separate control over different stages of the closing cycle.

Closing speed

This controls the main movement of the door from the open position towards the frame.

A door that closes too quickly can strike users, while one adjusted excessively slowly may remain open longer than intended and can be inconvenient in high-traffic areas.

Latching speed

The final few degrees of travel usually require separate adjustment.

The closer needs sufficient momentum and force to overcome:

• latch resistance
• door seals
• electric strikes
• weather seals
• minor pressure differences between rooms

If a door reaches the frame but repeatedly fails to latch, simply increasing the main closing speed is not necessarily the correct solution. Check the latch, strike alignment, hinges, seals and latching-speed adjustment first.

What is backcheck?

Backcheck provides hydraulic resistance as the door approaches the wider part of its opening arc.

Its purpose is to help control a door that is being opened aggressively or affected by wind, reducing the likelihood of the door, closer arm or adjacent wall being damaged.

Backcheck should not normally be treated as a substitute for a correctly positioned mechanical door stop where one is required.

For high-use commercial entrances and exposed exterior openings, adjustable backcheck is a valuable feature to consider during closer selection.

What is delayed action?

Delayed action allows a door to remain in the earlier part of the closing cycle for longer before continuing to close at its normal controlled speed.

This can be helpful where users need additional time to move through the doorway, including some healthcare, aged-care or service applications.

Always assess how the opening is actually used before specifying this function.

Regular-arm mounting

With a conventional regular-arm installation, the closer body is generally mounted on the pull side of the door, with the arm connected to the frame.

This arrangement provides efficient transfer of the closer's spring force and is common on commercial internal doors where the projecting arm is acceptable.

• efficient closer geometry
• simple installation on suitable doors
• good closing performance
• wide availability of closer and arm combinations

The main disadvantage is that the arm projects from the door and frame, making it more visible and potentially more exposed to accidental damage or abuse.

Parallel-arm mounting

Parallel-arm installation normally places the closer body on the push side of the door. When the door is closed, the arm sits much closer and approximately parallel to the door face.

This makes parallel-arm mounting popular for corridors, public areas and locations where reducing arm projection is desirable.

It can also help place the closer on the protected interior side of some outward-opening exterior doors.

Because the mounting geometry differs from a regular-arm installation, the effective closing force can also change. Do not assume that a closer will deliver identical performance in every approved mounting configuration.

Check the manufacturer's power rating and installation template for the actual mounting arrangement.

Top-jamb mounting

Top-jamb mounting places the closer body on the frame rather than on the door leaf.

• the door has a narrow top rail
• there is insufficient door surface for the closer body
• the door contains extensive glazing
• the closer is better supported from the frame

The available frame face, reveal depth and arm geometry must all be checked before ordering.

Do not assume every surface closer can be installed in every position. Follow the installation template supplied for the exact closer model.

Slide-track versus projecting-arm closers

Slide-track closers use an arm that travels within a track rather than the traditional articulated projecting arm.

The result can provide a cleaner appearance and a lower-profile installation, making slide-track closers popular in architectural and higher-specification commercial openings.

However, appearance should not be the only consideration. Check available power range, opening force, door width and the specific mounting arrangement before substituting a slide-track closer for a standard arm closer.

External doors need extra consideration

Exterior commercial doors are often more demanding than internal doors.

• wind pressure
• building pressure
• door seals
• weather seals
• heavier door construction
• larger leaf dimensions

An exposed door that operates correctly on a calm day may behave very differently during strong wind.

The closer should therefore be selected for the actual environment rather than only the theoretical door weight.

Where wind loading is severe, also consider suitable door stops and opening-control hardware rather than expecting the closer alone to absorb repeated impact loads.

Commercial door closers and fire doors

Fire and smoke-control doors require particular care.

The closer must be appropriate for the approved doorset and capable of reliably returning the leaf to the closed position.

Do not assume that a closer is suitable for a fire door simply because it physically fits.

• the fire-door manufacturer's requirements
• the door schedule and consent documentation
• the closer's fire-door approval or certification
• required power size
• mounting position
• arm and mounting-plate compatibility
• any requirements applying to hold-open devices

Be careful with hold-open arms on fire doors

A mechanical hold-open closer arm can be useful on ordinary doors where users intentionally want the leaf to remain open at a selected angle.

It must not automatically be treated as suitable for a fire or smoke-control door.

Where a fire door is intended to remain open during normal operation, an approved automatic hold-open arrangement linked to the appropriate detection or fire-alarm system may be required so that the door releases and self-closes during an alarm condition.

Always confirm the requirements for the specific doorset and project.

Door closers and access-control hardware

When a closer is installed on an access-controlled door, it needs to work as part of the complete door system.

A correctly selected electric strike or mortice lock will still create problems if the closer cannot reliably return the door to the latched position.

• closer
• electric strike or lock
• mechanical latch
• hinges
• door-position monitoring
• seals
• exit hardware
• access-control system

If the site uses electronic locking, our guide to electric strikes, maglocks and mortice locks explains the main locking options and their applications.

Installation matters as much as closer selection

Even the correct closer can perform poorly when it is installed incorrectly.

• incorrect arm geometry
• using the wrong mounting template
• insufficient fixing strength
• incorrect closer position
• poor hinge alignment
• excessive valve adjustment
• using a mounting configuration not approved for the closer
• trying to compensate for a door or lock problem through closer adjustment

Use the manufacturer's template for the exact model and mounting configuration. The drilling dimensions determine the closer's leverage and available opening angle and should not be estimated by eye.

Commission the whole opening

Once the closer is fitted, operate the door repeatedly from different opening positions.

• opens smoothly
• does not bind
• does not open with excessive resistance
• closes at a controlled speed
• enters the latch smoothly
• fully latches without assistance
• does not slam
• does not strike adjacent walls or hardware
• operates correctly with the access-control system

For fire and smoke-control doors, reliable closing from the open position is particularly important.

Commercial door closer selection checklist

1. Door width: Which EN power range is appropriate?
2. Door weight: Is the leaf unusually heavy?
3. Location: Is the door internal or exposed externally?
4. Usage: How frequently will the door operate?
5. Mounting: Regular arm, parallel arm, top jamb or slide track?
6. Opening angle: What maximum opening is required?
7. Functions: Are backcheck, delayed action or hold-open required?
8. Fire rating: Is the closer approved for the relevant doorset?
9. Accessibility: Can opening force be kept appropriately low?
10. Locking hardware: Will the closer reliably overcome the latch and seals?
11. Fixings: Can the door and frame support the chosen mounting?
12. Environment: Are wind or pressure differences likely to affect performance?

Choosing commercial door closers in New Zealand

The best commercial door closer is not necessarily the largest or most powerful model available. It is the closer that provides enough controlled force to reliably close and latch the specific door while remaining practical for the people who need to use it.

Start with the door dimensions and operating environment, then select the required power range, mounting arrangement and control functions. For fire, smoke-control and accessible openings, also verify the requirements applying to the complete doorset rather than selecting individual components in isolation.

Essential Security Supplies supplies commercial door closers and door-control hardware for New Zealand security, access-control and commercial door installations.

If you are unsure which closer power range, arm configuration or mounting accessories suit an opening, contact Essential Security Supplies with the door width, approximate weight, door construction, swing direction and application details before ordering.