by Kevin Blaine
Revolving doors are now becoming more integrated with a building’s emergency and security systems than ever before, and this means installers at the very least have to know more about how these systems tie into the door.
Revolving doors are a suitable solution for commercial buildings due to their appealing aesthetic appearance at the entry and their ability to minimize the influx of unconditioned outdoor air and unwanted noise and debris.
These doors are beneficial in all types of climates, even warmer areas. They keep conditioned indoor air within a building no matter how many people enter or exit the facility. In fact, the more pedestrian traffic there is, the greater the benefit compared to swinging and sliding doors.
In 2006, a team of graduate students at the Massachusetts Institute of Technology (MIT) published a study entitled, “Modifying Habits Towards Sustainability: A Study of Revolving Doors Usage on the MIT Campus.” The students focused their research on one particular building on campus with revolving and swing doors. By calculating the energy lost through the swing doors versus the revolving type, they concluded the latter was eight times more energy-efficient than the former because a large hole is created in the building envelope when the swinging door opens compared to the slight leak of air from a revolving one. The more a swinging door is used by pedestrians, the longer the hole stays open, resulting in energy loss.
One can maximize the use of premium indoor space, reduce loads on the HVAC system, save energy, and reduce operational costs by employing revolving doors.
The most important decision to make is which type of revolving door to use on a specific project. There is more variety than ever before, such as all-glass and metal-framed construction, and a choice of manual or automatic operation. Unlike yesteryear options, today’s manual revolving doors use electricity to provide power assistance, rotation control, positioning, and automatic security locking or integration with access control systems. There are also automatic security revolving doors to prevent tailgating and piggybacking into secure areas.
The best door type and features for an application would be the subject of a different article. This article will focus on ensuring a smooth installation. The author has witnessed hundreds of door installations over the past 30 years, and there has been many a time when the site was not ready for a revolving door installation. When this is the case, the installation team will charge the responsible party for a day of lost work (the opportunity cost of not working productively elsewhere), which can get expensive and is unnecessary. In the author’s experience, coordination is everything.
Door installer’s scope of work
It is important to understand the scope of work of a door installer. An installer’s main responsibilities include:
- erecting the revolving door properly within the awaiting opening structure;
- tying the door into the opening/building structure and floor using approved anchorage;
- sealing the door to the opening using approved sealant;
- commissioning the door, which includes testing its functions and performance to meet everyday use and building inspections (e.g. fire and access control systems); and
- communicating with the manufacturer when the door is commissioned and activating the product warranty period.
To accomplish these objectives, the site must be ready. Often a general contractor (GC) wants to install a revolving door to ‘seal’ the building envelope for security reasons and does exactly that. Further, the installation is often performed at an early stage when heavy equipment and ladders are still going in and out of the building and exposing the door to damage not covered by the manufacturer. In the author’s experience, the best approach is to have a temporary ‘door’ to close/secure the opening (plywood works) and wait until all the drywall is finished and painted.
The installer should inspect the site one to two weeks prior to the scheduled date, but it is important to understand that each type of door would have slight differences.
Flooring conditions matter
For a long product life, it is essential to install a revolving door on top of a completely leveled and finished floor, including carpet, tile, etc. If the floor is uneven, shims may be required to level the door. However, by doing so, there will be a gap in the seal underneath the door wing where the floor is lowest, which will allow unwanted air infiltration. Also, the uneven floor can cause undue stress on the bottom bearing of the center shaft, which will be rotating out of plumb. This can lead to premature failure over an extended period of time. If the floor is out of level by more than 3 mm (1/8 in.), it should be repaired prior to installation of the door.
It is recommended to use felt/rubber or a combination of horsehair and rubber under the door wings as weather stripping because they are always in contact with the floor. These flexible materials would not damage the surface and also ensure the door closes and seals properly without causing excess wear and tear on the door wings. If the floor is out of level, these materials will wear out or break down faster due to excessive contact and scraping.