[sholladay]

Revolving doors are awful. Except that they, allegedly, save energy.

My gut says that more confirmation studies are needed on the energy savings. I mean yes, they technically keep the building sealed, but they operate like a giant fan, constantly forcing the exchange of indoor and outdoor air. I would expect that they waste energy, not save it.

[wahnfrieden]

There are a bunch of studies showing it more definitively than your gut and secondhand knowledge of allegations

[sholladay]

If HN allowed me to edit (can't because it's two days old), I would change "allegedly" to "apparently". Of course there are studies, that is precisely what I was referring to. The fact that studies have shown energy savings, which contradicts what I would expect based on my own mental model of the world and gut feeling, is what I find remarkable. Don't you love it when science challenges your beliefs? I do. I remain somewhat skeptical, but I'm open to the idea that I am just wrong.

The MIT study from 2006 is pretty good.

https://web.mit.edu/~slanou/www/shared_documents/366_06_REVO...

However, I would note:

1. The MIT study makes a lot of assumptions (which they acknowledge).

2. In particular, the MIT study didn't put much effort into carefully measuring real conditions, e.g. using a blower door test. I'd like to see a study that does.

3. The MIT study was arguably more concerned with the psychology of door usage than energy.

4. Other than the MIT study, modern research on this topic is actually pretty sparse. There have been numerous examples of old studies not being reproducible, so I think it's fair to want a reproduction with current materials and building practices.

5. Some of the studies I've seen did not ensure the weather seals were equivalent. Revolving doors tend to have beefier seals. In my opinion, that makes the comparison less meaningful.