ceiling fans with AC?

I was in a large public room last week, with 30 foot ceilings, and 7 ceiling fans spinning, on poles that put the blades about 10 feet below the ceiling. The blade asssemblies were 3 or 4 feet in diameter. All but one fan was running about 100 rpm, and the one fan was 2 or 3 times that speed, and I couldn't feel any breeze from the fans.
I certainly understand using c.fans in the winter, to blow the hot air that rises to the ceiling back down to the people who are closer to the floor.
But when AC is on, wouldn't it be better to let the cold air sink to near the floor and let the hot air 25 feet up just stay up there??
Today I was in a large public room with 10 foot ceilings and a whole bunch of fans mounted to the ceiling with blades about 1 foot below. Same question.
Thanks.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
mm wrote:

Allegedly less AC cooling is needed with fans because the moving air cools the skin by evaporation. The fans may help also to move stale air when the room is crowded so folks don't faint.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

With vaulted ceilings in 3/4 of my home (12' at their peaks), ceiling fans make it feel 2-3 degrees cooler with ceiling AC vents pointed right at them.
I have the fans (in the vaulted ceiling rooms) mounted on 18" poles.
(In Florida, so I do whatever I can to make this house cooler)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

some ideas: add fresh air for sufficient air changes, break up the air temp layers, system needs to also be sized to population since humans are heaters, and monitor temp/humidity/oxygen levels. or see: http://www.buildingscienceconsulting.com/resources/mechanical/default.htm
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.