Effectiveness/efficiency of HVAC circulate mode?
Last time I replaced a thermostat, I got an Aprilaire that has a ‘circulate’ timer. If heat or AC has not been used for an hour, the stat will run the fan for 15 minutes and then restart its timer. The claimed benefits are reduced stratification and improved AQ (more trips through the filter). On the other hand there’s the cost to run the fan and wear and tear.
Anecdotally, there does seem to be a reduction in stratification that’s most noticeable when the weather is in between heating and cooling temps. It’s also nice to get a little almost-free warmish air in our corner bedroom after the night-time setback.
Has anyone seen data on real costs and benefits of circulate mode?
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