My wife and I recently went out to dinner with some friends.  Knowing that I write these posts, one friend commented on the revolving door at the entrance and asked whether it saved energy.  The short answer is yes, and they’ve been doing it for over 100 years.

Originally patented on August 7, 1888 by Theophilus Van Kannel of Philadelpha the door was designed to reduce the entrance of wind, snow, rain or dust.  The patent goes on to say that the door could not be opened by the wind and that people could go in and out at the same time without the possibility of colliding with one another.  Most of these benefits concern the comfort of the building, but they easily translate to energy efficiency in the modern day.  Originally, his main motivation for designing the door was supposedly driven by his dislike for chivalry because he despised walking in and out of a building, encountering others and having to insist that they go first.  But most of all, it is said that he couldn’t stand the expectation of opening doors for women.  Whatever his motivation, he designed a door that is still in use today and is still saving energy.

A revolving door saves energy by ensuring that the inside of the building is never directly open to the exterior.  Doors are built in a way that the path of air is always blocked no matter where the door turns.  When you open a conventional door, air can flow freely in or out due to a variety of factors which causes the building equipment to work harder to heat or cool the newly introduced air.  A lot of buildings will solve this by adding a vestibule (a small room with exterior and interior doors) which also attempts to reduce the amount of time the interior is open to the outdoors.  A revolving door takes up less space than a vestibule and, depending on traffic, would block more air transfer.  Unfortunately revolving doors aren’t usually a good solution for a building with a lot of foot traffic.

Strategies to reduce infiltration, such as vestibules and revolving doors, are a great way to reduce energy usage.  There are also many low to no cost improvements that can be made to most buildings that can start saving you money right away.  If you are interesting in saving money on your building by saving energy, consider hiring us to complete a Small Business Energy Audit.  We will review your building and provide you with options for saving money. Our goal is to provide an affordable service that a business can use to reduce their energy costs.  We are happy to work with you to find a solution that fits your budget.  If you own or manage a building and are interested in an audit, please contact us today.