Backcheck, latching speed and closing delay – what does it all mean?
When choosing the right door closer for your building environment, there are a range of additional functions available that can help ensure a solution is perfectly suited to meet your needs.
These include backcheck, latching speed, and delayed action functionality – but what does each one of these features entail, and how can they help achieve greater control, and be more user friendly?
Backcheck
What is backcheck on a door closer?
A closer with backcheck ensures the opening motion of a door is hydraulically dampened from an opening angle of approximately 75o.
Why might backcheck be needed?
Backcheck essentially stops a door from being thrown open.
What installations might require backcheck?
Should wind speeds pick up, then an external door is potentially at risk of being thrown open by the wind, which can damage the frame and hinge, so this type of application would benefit from backcheck. Another example might be an internal door where there’s a wall 90o from the door. Again, backcheck prevents a door like this from being thrown open, stopping any damage that might occur to the door or the wall.
Preventing this damage can help elongate the life of the doorset, and so reducing the overall cost of operating the building.
Latching speed
What does latching speed refer to?
When talking about the latching speed of a door closer, this refers to the speed of the door leaf in the final 15o of closing, until it reaches its fully closed position.
What is this designed to do?
The latching speed intends to overcome the resistance of a door latch in the last stage of closing, while making sure the door is secured quietly without slamming.
What should the latching speed be?
The latching speed of a closer is adjusted on site, and should be tailored to the opening in question. This is to achieve the perfect balance between ensuring the complete closure of the door vs slamming, or trapped fingers.
Closing delay
What does closing delay mean?
This refers to a delay in the system’s closing speed between its maximum acheivable opening angle (max 130 degrees) to around 70o.
What does this delay achieve?
Because the speed of the closing motion is slowed down, it provides users with additional time to pass through the door.
Why is this important?
Delayed action is not hold-open. Its primary use is for single room doors only, not circulation routes or doors. This type of feature can be very useful in areas such as operating theatres, care home communal room doors, and store/gym equipment rooms.
This functionality gives people a bit of extra time to pass through the doorway with ease, particularly if they are impaired in any way - for example, wheelchair users, people carrying a box, or pushing a trolley etc.
