James White of Record UK breaks down the various factors to consider when specifying a revolving automatic door
Revolving doors are a great way to create a grand, visually stunning and welcoming entrance to a building. They also prevent unwanted air infiltration, reduce energy costs and contribute to a superior indoor climate, making them a popular choice for architects, specifiers and end users.
As with all automatic door systems, the key to success post-occupancy and overall client satisfaction, is correct specification from the early design phase. This is where the manufacturer’s specification managers enter the equation offering technical advice and support in the design and integration of the revolving door to all involved.
After all, if the revolving door becomes a barrier to access due to incorrect specification, it may lead to dissatisfaction once in operation due to queues forming at peak times. To avoid this and ensure success, there are many factors that should be considered.
Floor space, occupancy and peak flow
The theoretical pedestrian flow rate of a revolving door is dictated by its proposed internal diameter, quantity of wings, and peripheral speed (constrained by regulation EN16005). Therefore, an understanding of the predicted demand at peak times is essential to determine the minimum diameter of revolving doors required, as well as the overall number of units.
As an example, a typical four-wing automatic revolving door with a diameter of 2400 mm, rotating at 0.77 m/s or 6.12 rotations per minute, would have a throughput capacity of approximately 31 people per minute or 1,900 people per hour, based on one person occupying each segment.
Of course, a large influx of workers will enter an office building between 8:30 am and 9:30 am each morning. A single revolver might quickly become overwhelmed when large volumes of pedestrians arrive at the same time. A pass door may be needed as an alternative point of entry – somewhat defeating the indoor climate benefits intended when selecting a revolving door. This is particularly relevant during inclement weather conditions and additional doors should be considered to remove the risk of queues forming, especially considering the current need for social distancing.
As an alternative, a high throughput 360O curved sliding door system might be a consideration or even as an addition when pedestrian footfall demand might overwhelm a revolver’s capacity. A curved sliding door offers relatively unimpeded traffic flow, it can be used on an emergency escape route and can create a very similar aesthetic to a revolving door. It is more challenging to control the indoor climate with this type of system but the addition of a warm air curtain, reduced opening width in the winter and interlocking the inner and outer doors (where possible) can help to negate this. The added benefit of a curved slider is that you do not need a separate pass door.
Delays caused by sensitive protective equipment Revolving doors are safer than ever but to ensure their safety in use they must comply with EN16005 which states the minimum required measures to protect pedestrians using an automatic door system. A specification manager should be EN16005 certified and carry out a risk assessment on every automatic door they specify to ensure the door system will be safe in operation and suitable for the application.
On a revolving door there are multiple danger points (highlighted in the image above) which are protected by a combination of ESPE or PSPE sensors (electro-sensitive protective equipment/pressure sensitive protective equipment) which, when activated, are designed to stop the rotation of the door to prevent injury. These are sensitive sensors that need to be easily activated. A sensor on the bottom of the revolving wing will, if it catches someone’s heel, stop the automatic door. After a short delay to remove the person’s foot from the door, the door moves again.
The sensors are there for a very good reason; however, if the door segments are too small and people are shuffling through them, these sensors can be easily activated resulting in frustrating delays and unimpressed end users.
The classic four-wing revolver is the most popular choice, particularly suitable for higher volume, two-way pedestrian traffic flow requirements in commercial office applications. It also offers improved indoor climate control due to the construction of the leading mullions and wings that form an improved seal.
A three-wing offers a slightly lower throughput capacity and narrower clear opening but offers more comfort as there is more space in each segment and is therefore better suited to low traffic environments. Comfort can be further improved by integrating a warm air curtain with either electrical heat or warm water fed into the canopy.
A manufacturer will also assist with the integration of the system into the facade of the building using either glass to glass, glass to metal or metal to metal facade connections, depending on the positioning of the door system and facade construction.
There are typically two types of security required. Physical – break-in attempts – requiring testing to standards such as EN1627 incorporating RC1 – RC6 and PAS 24, and LPS 1175 incorporating ratings from SR1 – SR 8.
Secondly, operational security relates to ‘anti-piggyback’ and ‘anti-tailgating’ technology to prevent unauthorised access.
One automatic option, an overhead drive, enables the designer to incorporate a warm air curtain and lighting into the solid roof canopy of a revolving door maximising user comfort. In-floor operator options (where floor space allows) are available for automatic curved sliding, revolving and linear sliding door systems. When combined with an all-glass type construction help the designer deliver a minimal aesthetic, maximise light transmission and help to create the ultimate wow factor.
To summarise, it’s vital to ensure the requirements of both the building envelope and building owner are met at the specification stage. Getting advice from a manufacturer’s specification manager enables a specifier to avoid misunderstandings which can lead to safety issues, delays in installation, and time and money being wasted.
James White is specification manager at Record UK