Author Topic: HVAC Circulating Fan Setting  (Read 765 times)

Ben

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HVAC Circulating Fan Setting
« on: June 20, 2021, 10:20:18 AM »
Since December, I have been using the "circulate" setting on my tstat for the HVAC fan instead of auto. It turns the fan on every few hours and circulates air through the house. I felt like it made a difference, both in comfort and in using less heating/cooling, but I really had no way to judge or measure. I think I have good data now.

My Honywell tstat sends me monthly reports on hours of heating/cooling per month and compares them to the  same month in the previous year, including average inside and outside hi/low temps. Of course most of the time you can't really use that annual comparison because you don't have consistent monthly outside temps. For this May though, it showed I had the same hi/low average outside and inside temps as May 2020. While the extremes and times might affect accuracy, this is probably as reliable a comparison as I'm going to get.

This May, using circulate, I had 46 fewer hours of heating and 8 fewer hours of cooling than May 2020. I believe this was mostly due to using the circulate feature. Especially on the heating. I like to use my wood stove a lot, but from where it is, it mostly heats the living room / kitchen areas. I think "circulate" helped send that heat throughout the house, especially to my bedroom. Also I have a bonus room upstairs that of course captures rising heat, and I think "circulate" helped redistribute some of that air to the rest of the house. For cooling, May doesn't really get hot, and in fact my first May here there was even a little snow, so the lower "saved" number makes sense.

Anyway, it looks like whatever extra electricity that "circulate" uses to run the fan is more than offset by less HVAC use.
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WLJ

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Re: HVAC Circulating Fan Setting
« Reply #1 on: June 20, 2021, 11:01:41 AM »
Been using the circulate feature for years but never did any kind of usage/bill comparison. I like the fact it helps even out the hot/cold spots in the house when the heat/AC isn't running so much. Also helps clear out the bathroom after a hot shower
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K Frame

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Re: HVAC Circulating Fan Setting
« Reply #2 on: June 21, 2021, 06:45:52 AM »
My fan's been running for something like 20 years. Rarely shut it down. The main reason is to even out temperatures, but a huge secondary benefit, especially with a big dog who can track in amazing amounts of crap in her fur, is the constant air filtration.
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MechAg94

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Re: HVAC Circulating Fan Setting
« Reply #3 on: June 21, 2021, 08:51:03 AM »
My fan's been running for something like 20 years. Rarely shut it down. The main reason is to even out temperatures, but a huge secondary benefit, especially with a big dog who can track in amazing amounts of crap in her fur, is the constant air filtration.
Your AC is in the basement correct? 

I have left mine on before and the humidity went up in the house almost to the point of surfaces being damp in the morning.  My AC is in the attic so circulated air runs through ducts in the attic when the attic temperature is a bit warm.  It might work okay if it was intermittent, I don't know.
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K Frame

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Re: HVAC Circulating Fan Setting
« Reply #4 on: June 21, 2021, 10:02:16 AM »
Yes, basement.

My basement gets quite humid, and it does pull that air up into the main part of the house, unfortunately. I have dehumidifiers in both the basement and on the second floor.

One of the drawbacks to upping the insulating in my house back in 2010 was that, because the system didn't run so much anymore, the humidity levels spiked.
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Brad Johnson

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Re: HVAC Circulating Fan Setting
« Reply #5 on: June 21, 2021, 11:22:12 AM »
A couple of ceiling fans on low and a regular circulation schedule does wonders for perceived air quality and general comfort. As K Frame mentioned, helps with filtering, too.

Brad
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K Frame

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Re: HVAC Circulating Fan Setting
« Reply #6 on: June 21, 2021, 12:48:41 PM »
I have a ceiling fan in my bedroom. It's fantastic. I've been meaning to put a ceiling fan in my living room but have not yet gotten around to it.
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MillCreek

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Re: HVAC Circulating Fan Setting
« Reply #7 on: June 20, 2022, 11:27:31 AM »
I was reading on a local FB page where a HVAC expert was recommending running the fan on a heat pump setup.  I remembered we had discussed this some months ago and found this thread.  I just checked and our Honeywell thermostat has a 'circulate' setting, so I just switched that on as per Ben's post.  If our HVAC experts think this is not a good idea for a heat pump, as opposed to the separate AC systems mentioned here, please chime in.
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