Automatic and revolving doors generate energy savings, improve operations, enhance user experience, and attract occupants and tenants. But if you’re considering installing one or the other to seize these benefits, making a selection doesn’t require shopping door-to-door.
Certainly not an open-and-shut case, your decision will depend on space availability, traffic flow, ADA compliance, and energy savings potential. Read on to try and close the door on this debate at your facility.
Energy Performance Spurs Retrofits
Because automatic doors open only when an incoming user triggers them, the possibility of doors being left open accidentally – a costly mistake when HVAC systems are operating – is eliminated, says Donald Moerbe, president of the American Association of Automatic Door Manufacturers (AAADM).
Even though the doors are powered, they can actually help conserve energy with tight, secure seals.
“Automatic doors are essentially used as an air lock to help manage expenses,” Moerbe explains, attributing the performance to the vestibule setup of two separate sets of doors. “There are also a variety of models available with low-energy motors.”
Revolving doors also combat air infiltration. “Energy loss depends on how many times the door is open, how large that opening is, and how long it lasts,” says Tracie Thomas, marketing manager for revolving door manufacturer Boon Edam Inc. “Because they’re always open yet always closed, revolving doors provide the least amount of infiltration possible.”
MIT researchers considered the effects of revolving doors at several of their campus locations in Modifying Habits Towards Sustainability: A Study of Revolving Door Usage on the MIT Campus.
A revolving door is only effective if it is used, however. The study found a usage rate of about 68%. Average daily cost of energy due to air leakage at MIT was $13.10 during the winter, but a 75% usage rate of revolving doors drops the cost to $7.66, while 100% usage would drop it to $2.83.
Thus, two revolving doors at one building could save almost $7,500 yearly in natural gas used to heat and cool, amounting to nearly 15 tons of CO2 emissions.
A revolving door retrofit can be performed in weeks, Thomas says, but motivation to do so depends on a number of factors.