Install destratification fans

Eco12m, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons

In theory, if you have high ceilings and the air is a lot warmer at ceiling level than where people are, destratification fans are useful for pushing the warm air down. They work well in places like warehouses or spaces where people are active. They are much less popular in spaces where people are sedentary, because even a mildly warm draught will make people feel colder, especially if it’s on their head, the warmest part of their body. They can also be noisy.

Our heating advisor says that when he’s seen venues where groups have put them in, they end up not being used. However, destratification fans could be the right solution in some settings. For instance, in churches, they could be used just during the pre-heat period and turned off when people come in. They might also be useful in some sports halls that need a high ceiling, for instance, for playing badminton.

Check the temperature difference before buying

If you’re considering this action, you definitely want someone to check how warm the air at ceiling level is first and use that to assess whether the fans will pay back. The temperature difference is often smaller than people think and that in itself will rule fans out. For lower ceilings we’ve heard of people checking it using normal thermometers on a long pole. We’ve sometimes done this kind of testing using miniature monitors mounted on helium balloon clusters or by dangling commercial thermal monitors through light fittings or vents from above.

If you try this yourself, you’ll need the space at a steady temperature and to leave the monitor in the different locations long enough to adjust to each. Ideally, you’d use multiple monitors as the heating profile will change as the space warms. Whatever you do, be very careful - even a small object can do a lot of damage to people or flooring if dropped from height.