What is the best way to circulate heat downward in a room with 14' ceilings where the heat ducts are at the top?

Question

What is the best way to circulate heat downward in a room with 14' ceilings where the heat ducts are at the top?

Asked by Lindsey

I have a loft-style condominium with 14' ceilings and ducts at the top, as well as expensive electric heat. In the winter, at ceiling level the temperature will be 90 degrees whereas at ground level it will be 60 degrees, which causes my furnace to have to run continuously. The room is 35' x 18', and I currently have one ceiling fan at the rear that I can run in reverse. The front half cannot accommodate a standard ceiling fan in the middle, however, due to a hanging 8' x 8' loft bedroom that is open on the two wall sides. What would be the most effective way to circulate heat down and reduce my heating bills? Install several 12"-18" standard fans a few feet below ceiling height on the wall, then point them towards the ceiling? Install standard wall fans at ceiling height and point them downwards? Or install two miniature (24") ceiling fans on either side of the loft bedroom, and run them in reverse?

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graham swett's picture

Submitted by graham swett on Fri, 01/07/2011 - 13:47

Hi Lindsey --

Sounds like a great space!

From your description, I am picturing a ceiling that has everything exposed -- a very industrial look. If that is the case, you may not mind the appearance of a product called the Air Pear.

  • You'll see from the website that it is typically specified for more commercial applications, but sounds as though it would be an option if you are OK with the aesthetics.
  • The model 10 can be installed 12 to 18 ft from the floor and covers an area 35 feet in diameter.
  • Noise level is rated at 44 dbA, which is roughly equivalent to a quiet conversation. Electrical usage appears to be less than a typical ceiling fan.

So, assuming you are OK with the appearance and noise level, one Air Pear sounds like it will provide good results.

Pulling hot air off the ceiling

When we design homes with high ceilings we will frequently coordinate with the mechanical contractor to install return air registers high on the adjacent walls to "pull" the hot air off the ceiling and recirculate it back to the heating equipment, thus destratifying -- and, as you pointed out, saving the homeowner money.

  • In your situation, with the supply registers being high, I would be concerned about trying this approach, as it would likely "short-circuit" the air flow.
  • It is interesting that the heating system was installed as you describe.

Relocate your supply registers

One other thought would be to work with a mechanical contractor and see if it would be possible to relocate your supply registers down at floor level and introduce high return air registers into the system as mentioned above.

This, however, is not an inexpensive solution.

Other cost effective ways to modify your system

The Air Pear is probably your best value from a first cost and operational cost standpoint. Appropriately placed quantities and sizes of standard ceiling fans is another most cost-effective option.

In any case, I think you would benefit from having a reputable heating/air conditioning contractor look at your space and determine if there are any simple cost-effective ways to modify your existing system for greater comfort and efficiency.

Hope this helps and gets you closer to finding a solution!

For more information:

Use GreenHomeGuide's Find a Pro directory to locate a green hvac contractor near you.

Read Kevin Holdridge's Q&A "How do you insulate a home with cathedral ceilings?"

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