Any new data on ceiling fan use in winter in vaulted ceilings?
emma_vt
| Posted in General Questions on
Does anyone know of recent data on the efficacy of ceiling fans at moving warm air down in winter – particularly in a vaulted ceiling? We’ll have AC, so I’m not concerned about summer months. All the articles I’m finding are getting to be 10-20 years old. The living room in the house we’re building has a vaulted ceiling and I’m trying to decide if it’s valuable or at-best-negligible to put in a ceiling fan as opposed to a light fixture. Thank you!
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Emma,
You may find these GBA articles useful:
https://www.greenbuildingadvisor.com/article/ceiling-fans-are-evil
https://www.greenbuildingadvisor.com/article/the-important-stuff-you-need-to-know-about-ceiling-fans
I perused the articles and comments Malcolm posted. There seems to be a lot of doubt about the use you've suggested (mixing stratified warm air at the ceiling). I don't have data, but what I can say is this: I have a small cabin with a vaulted shed roof, with a sleeping loft on the high side. No air conditioning. There's a ceiling fan in the living area below the loft. If I sleep in the loft without a fan running, it's pretty damn warm, even when it's quite cool outside and cool downstairs. If I turn on the ceiling fan (blowing upwards), it brings the loft temperature way down, similar to downstairs, and it's very comfortable up there. By definition, then, it has to be warming it up downstairs. So it seems pretty obvious to me it's doing a good job mixing the air.
I was just thinking today that ceiling fans have really gone out of fashion. It used to be orthodoxy that a ceiling fan made a room more comfortable in winter by reducing stratification but I've never seen any rigorous scientific support for the idea.
The old GBA articles are primarily on the pit falls of ceiling fans and cooling. I do think the bulk of their merit now is in vaulted and cathedral scenarios in heating scenarios. Big Ass Fans (not surprisingly) has some compelling infographics - but man I'd love to see some primary articles!
https://www.bigassfans.com/heat-destratification/