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?
谢谢，
Cris (4A)
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这是一个舒适的问题，而不是效率问题。的确，空气会分层，因此多层房屋中的高层可能会变得太热，而最低水平太冷。循环空气将有助于解决这个问题，因此将仔细调整阻尼器，以优化在加热周期中温暖的空气进行的位置。在一个非常紧密的房屋中，热周期不经常运行，循环模式可能会更有益。
您可能使用数百瓦的电力在循环模式下单独运行鼓风机。如果它在您的家中舒适地取得了明显的改善，那么跑步可能值得，但这是个人的喜好，并且在某种程度上也依赖您的特定房屋。
Bill
The wind-chill effects of room-temp air circulation can lower rather than enhance comfort. Stratifcation effects would have to be pretty severe to make it "worth it".
Good points. A 3/4hp blower is going to draw ~ 550w, so not insignificant.
The wind-chill effect is not a bonus in the winter but might act as a whole-house c*iling f*n in the summer. Whatever you may think about that...
谢谢，Bill and Dana.
我已经定时设置了大约1/3的时间。我有一个可变的速度空气处理程序，其1/2 hp ECM。它在“仅风扇”中以约50％的CFM运行，3吨空气处理程序的约80W。上面的数字似乎更像是带有PSC电机的空气处理器的球场。矿山的评分为 @ 350W，用于全气流 @ 0.5“ WC。
I feel having the circulation is a positive, particularly in the shoulder seasons when there are not so many calls for heat or cool. I can feel the cool air when it runs in winter, but the air streams from the registers are directed away from "living" space where we sit, etc., and so aren't bothersome. I don't think the circulation does all that much for stratification, at least for my two-story-with-big-opening-between-the-floors house. It does help with circulating more air through the bedrooms at night, helping lower the CO2 levels there.
If/when I get the house sealed up to the point that the overall indoor air quality begins to go downhill, the circulation timer would facilitate supply-side fresh air ventilation.
We also have a 1/2 HP ECM air handler with our 2 1/2 tons heat pump and use the low speed fan (450 CFM- 50 to 60 watts) 100% at night in winter for circulation/comfort/air cleaning. Aprilaire 2400 filter changed once a year ($18-$20). The rest of the time it runs 5-10 minutes per hour, when heat pump is idle. We can't use low speed fan in summer (as desired) to eliminate upper/lower level stratification becaues it just evaporates the water on the A coil and sends the humidity level way up. Ceiling fans are used in the summer. 450 CFM low speed fan is hardly noticable. The same goes for 700 CFM in 'comfort' heat pump mode. Think slow, soft heat. The air handler is going on its 18th year of heavy use and still works great! I bet the compressor fails first.
贝内特，
It is indeed a PSC motor on an old Goodman 80% furnace that might be twice as big as the house needs. I do think the circulation does help with air quality in the bedrooms.
我有一个ECM粉丝，如果我不参加con van，我的每日kW/h消耗量几乎几乎看不见（可以在我的公用事业网站上进行检查）。有一个颠簸，但我想说的是每天接近1WK/HR，每天的平均值从大约14增加到约15kW/hr。