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For new home construction, in rooms with cathedral ceilings, is there any alternative to using standard ceiling fans for circulating heated/AC air within the room? I like the open sweep of the high ceiling and would like to avoid installing “helicopters” if possible.
I’m thinking of some type of fan/duct/register system installed inside the room’s end walls that would circulate the air top-to-bottom (and vice-versa).
Any suggested brands or manufacturers?
Thanks,
Pete
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Replies
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Pete-
What I'm thinking is you install whatever size duct with intake at the apex of the room, then run horizontal to a gable end. There, you penetrate the wall and ell vertically down running the duct so that it is near enough the exterior skin that the air inside the duct is substantially cooled. This air will then settle down the duct, exiting the wall thru a register installed 8 or 9 ft. above the dnstrs floor. The cooled air will institute a thermosiphon, recirculating ridge air. The circulation will, I imagine, serve to de-stratify the room. The air exiting the lower register will be cooler than air at the apex, but you'd have to experiment to see what the temperature relationship between siphoned air and lower room air is in various conditions. If the effect of exposing room air to cooling in the duct can be balanced fairly efficiently by the home's heating system, you might end up with an effective, passive means of circulating air top to bottom in winter. In summer a similar effect could be achieved by distributing conditioned air from registers placed high in the room. The cooled air would settle from the registers, roiling the air into destratification.
*Well I think I must be the only person on the Forum who has the sense to favor forced air HVAC. With proper placement of supply and return ducts in a forced air system you can get good air flow, comfort and efficiency without fans. I've seen it done by others and I've done it and it isn't any big deal.
*Regarding the thermospihon idea: You won't get much cooling in the downward duct. Not enough to move the 100-500 cfm of air that you would like to. But a blower in the duct would do it. Lots of ways to do it with blowers. In the summer, you might want to be able to dump hot air outside. In the winter, you want to stir things up by reintroducing that warm, high air down low. -David
*I should have explained our plan in more detail: see the attached FLOORPLAN.GIF image. It's a 2400 square foot ranch over a crawlspace, with a 15' peaked ceiling over the open central area (Foyer, Dining Room, Great Room, Kitchen, and Breakfast Nook). There are 10' flat ceilings throughout both bedroom wings.The forced air furnace (with central AC) will be installed in the crawlspace. I'm trying to keep things standard and as simple as possible and want to avoid any unusual solutions.Generally speaking, would reversible air ducts/registers only be necessary in the end walls of the cathedral ceiling, at its peak? Or would ducts/registers also be necessary in the middle of the ceiling?Pete
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For new home construction, in rooms with cathedral ceilings, is there any alternative to using standard ceiling fans for circulating heated/AC air within the room? I like the open sweep of the high ceiling and would like to avoid installing "helicopters" if possible.
I'm thinking of some type of fan/duct/register system installed inside the room's end walls that would circulate the air top-to-bottom (and vice-versa).
Any suggested brands or manufacturers?
Thanks,
Pete