Home & Garden

HVAC thermostat fan - Auto or on?

  • Last Updated:
  • Jul 4th, 2021 9:45 am
Tags:
SCORE
+1
1
0
Reply to ThreadReply
Jul 2nd, 2021 3:07 pm
kkil4life [OP]
Newbie
Nov 16, 2017
64 posts
25 upvotes

Jul 2nd, 2021 3:07 pm

HVAC thermostat fan - Auto or on?

Hi Guys,
I was wondering what most of you guys leave your fan setting on your HVAC to - Auto or on?
I've just recently been leaving it "ON" and the house has been feeling cooler because it recirculates the air from the basement which is cooler, but I have noticed my daily energy consumption has gone up.
I'm guessing it should be around $30-$40 higher a month from leaving the fan in ON mode.

So my question is
1. what do you guys leave your fan on - Auto or On?
2. Does it really make a $30-40 difference? or do you think mine was just coincidental (I only measured for a few days).
3. Any pros or cons to either?

Thanks.
8 replies
Jul 2nd, 2021 3:11 pm
KevinM56081
Banned
Jun 4, 2020
1634 posts
1744 upvotes
Clarington, ON

Jul 2nd, 2021 3:11 pm

I leave mine on.

Does your furnace have a DC ECM motor?
Jul 2nd, 2021 3:16 pm
kkil4life [OP]
Newbie
Nov 16, 2017
64 posts
25 upvotes

Jul 2nd, 2021 3:16 pm

no idea about the kind of motor, how do I find out?
Jul 2nd, 2021 3:24 pm
thriftshopper
Deal Fanatic
Jul 7, 2017
9166 posts
4688 upvotes
SW corner of the cou…

Jul 2nd, 2021 3:24 pm

kkil4life wrote: ↑ no idea about the kind of motor, how do I find out?
Furnace model number would help. Picture of motor label even better.
I smile when I see container ships sailing past my house laden with stuff made in China
Jul 2nd, 2021 3:32 pm
fergy
Deal Fanatic
User avatar
Sep 27, 2006
5337 posts
2187 upvotes
Not so easy there Ma…

Jul 2nd, 2021 3:32 pm

Leaving the fan running could certainly add $30 to $40. As indicated DC motors use less than AC. If your furnace is an older model or an original builder installed furnace it's more likely to be an A.C. motor.
+1
Jul 2nd, 2021 11:32 pm
Double_J
Deal Addict
Feb 10, 2006
2620 posts
555 upvotes
Kitchener

Jul 2nd, 2021 11:32 pm

Fan is set to on 24hrs a day 365. Been running none stop for several years.

I'd only recommend switch to auto if the furnace is old (ac motor) or for elderly customers when they feel cold all the time.
Tired of renting from Reliance? This might be useful reliance-home-comfort-2464779/2/#p34473179
+1
Jul 3rd, 2021 12:52 pm
newlyborn
Deal Addict
Jun 16, 2009
3994 posts
2661 upvotes
Woodbridge

Jul 3rd, 2021 12:52 pm

Having the Fan run continuously will provide even distribution of hot or cool air. This will reduce hot or cold blind spots in the home. Continuously running Fan also reduced the stress on the fan from frequent starts and stops, which can potentially help extends its lifespan.
Most modern furnaces are equipped with ECM motors and the operating cost is minimal compared to the benefits it provides.
+2
Jul 4th, 2021 9:45 am
insertname2020
Deal Addict
Oct 19, 2020
1047 posts
673 upvotes
GTA

Jul 4th, 2021 9:45 am

Running the fan continuously re-evaporates moisture off the indoor coil when the call for cooling ends.
See here: https://www.energyvanguard.com/blog/thi ... -you-sick/
The larger the unit is relative to what it should be, the shorter the cycles which makes this problem worse.

Many furnaces out there still have inefficient fan motors which draw 300w+ on the lower speeds (usually heat/continuous fan), more on high so energy use can add up fast. The extra energy used ends up in the form of heat which needs to be removed by the a/c.
ECM motors start gradually so the stress on the motor due to cycling is greatly minimized.

Yes, can be helpful for balancing, but for most cases "auto" is the best setting at least during humid weather.
Hvac advice warning - inaccurate information on forum, vested interests in selling builder's equipment. Selling dealer-only brands without being authorized is a red flag. Report to CRA if offered no tax cash-deal. If it's 2 good to b tru, it is.
+1

Reply to Thread
Back to top
Top

Trending Hot Deals