Editing Revolving door (section)

== Research ==
[[File:Revolving Door Sign.jpg|thumb|Revolving doors are favored because they can be used as an [[airlock]] to minimize a building's [[HVAC|heating and air conditioning]] losses.]]
Research into the air and energy exchanges associated with revolving door usage have been carried out on a few occasions. The earliest such study was carried out in 1936 by {{nowrap|A.{{hsp}}M.{{tsp}}Simpson}},<ref>Simpson, A. M. and Atkinson, K. B. ''InfInfiltration Problem of Multiple Entrances''. Heating, piping and air conditioning, vol. 8 no. 6 pp 345 - 351, 1936</ref><ref>Simpson, A. M. ''Infiltration Characteristics of Entrance Doors''. Journal of refrigerating engineering, vol. 31 no. 6 pp 345 -350, 1936</ref> who worked for the van Kannel revolving door company at the time. Simpson's study was followed by a study by Schutrum et al.<ref name="SchutrumPaper1961" /> in 1961, and more recently a study by van Schijndel et al.<ref>Van Schijndel, H., Zmeureanu, R., Stathopoulos, T. ''Simulation of Air Infiltration through Revolving Doors'', Proceedings of Building simulations 2003 conference, pp. 1193 - 2000, 2003</ref> in 2003. These studies focused on providing detailed measurements of the quantities of air and heat transferred inside the compartments of a door as it revolves. With the exception of the study by van Schijndel et al., which was purely theoretical, the measurements carried out for the other studies were used to provide design charts enabling engineers to estimate the quantity of air transferred by a door in function of the revolution rate and temperature contrast. However, none of these studies are referenced by existing design codes.{{Citation needed|date=October 2023}}

The aforementioned studies are specific to the type of door which they were acquired for, namely {{Convert|2 x 2|m|ft|abbr=on}} doors with four compartments.<ref>Beardmore, A. ''The Revolving Door Since 1881: Architecture in Detail'', Boon Edam P.V., 2000</ref> Although it appears that these dimensions were standard for four-compartment doors at the time, this is not the case nowadays.{{Citation needed|date=October 2023}} A more recent experimental study<ref>Allgayer, D. M. and Hunt, G. R., ''Air Movement by Revolving Doors'', Proceedings of the RoomVent 2004 conference, 2004</ref><ref>Allgayer, D. M. and Hunt, G. R., ''Hybrid Ventilation by Revolving Doors'', Proceedings of the HealthyBuildings 2006 conference, vol. 4 pp. 215 - 220, 2006</ref><ref name="AllgayerPhDThesis" /> carried out at Imperial College London's [[Department of Civil and Environmental Engineering, Imperial College London|Department of Civil and Environmental Engineering]], provided more insight into the flow physics by which air is transferred across a revolving door.

Airflows and energy losses through revolving doors also occur as a result of leakages past the seals of the door. Leakages are common to any type of opening in an otherwise closed space, but have been investigated in the context of revolving doors by Zmeureanu et al.<ref>Zmeureanu, R., Stathopoulos, T., Schopmeijer, M. E. D. ''Air Leakage Through the Building Envelope via Revolving Doors'', Proceedings of the International conference on building envelopes, systems and technology, pp. 467 - 472, 2001</ref> and by Schutrum et al.<ref name="SchutrumPaper1961" /> before that. The first study concluded that to avoid significant leakages, the seals of the doors should be maintained and periodically replaced if needed. The second study produced design charts for estimating the leakage rate through a revolving door. Unlike the curves for estimating the transfer rate also published in this study, the curves for estimating the leakage rate are more generic. As such these design curves still form the basis of the target leakage rates for revolving doors recommended by the [[ASHRAE 90.1|ASHRAE standard 90.1]] in the US.<ref>ASHRAE ''ASHRAE/IESNA Standard 90.1-1999: Energy Standard for Buildings Except Low-Rise Residential Buildings'', US, 1999</ref>  On May 25, 2006, an MIT Study entitled "Modifying Habits Towards [[Sustainability]]: A Study of Revolving Doors Usage on the MIT Campus" was published.  In it, B. A. Cullum, Olivia Lee, Sittha Sukkasi and Dan Wesolowski concluded, "...substantial energy is saved when people use the revolving doors instead of swing doors – the smallest of habit changes contributes to [[energy conservation]]... Modification of one habit... indeed has the ability to eventually impact the environment on a global scale."

While preferred by building owners for energy conservation, revolving doors may be avoided by some people due to the perceived greater physical effort in using them.<ref>{{cite web|last=Cullum|first=B.A.|title=Modifying Habits Towards Sustainability: A Study of Revolving Door Usage on the MIT Campus|url=http://web.mit.edu/~slanou/www/shared_documents/366_06_REVOLVING_DOOR.pdf|publisher=MIT|access-date=7 November 2013}}</ref>