# HVAC Fan "ON" or "Auto"



## Brock

Do you recommend keeping the fan in the on position all year, or auto. 

I have always been told it is better to leave it in the on position year round.


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## MALCO.New.York

Brock said:


> Do you recommend keeping the fan in the on position all year, or auto.
> 
> I have always been told it is better to leave it in the on position year round.



I am with you on this one!!!



MALCO.New.York said:


> Absolutely correct! It keeps the air "flowing" and therefore amalgamates the ambient temperature.
> 
> It does away with Hot and Cold spots.
> 
> It takes more energy to start a blower motor than it does to run one. No idea how long equates to "start up". But frequent start and stop is VERY wasteful!


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## neolitic

"Leave it *on*," has been my 
personal crusade for 30 years.


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## cleveman

I remember in the instructions for my electronic air cleaner, it was stated to leave the fan on all the time for a month, then check and see if you can afford to leave it on.

Comfortwise, it is obvious that it is better to leave it on.

I'm going to find my multimeter and funky extension cord and get a reading on what it takes to run the fan.


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## neolitic

cleveman said:


> I remember in the instructions for my electronic air cleaner, it was stated to leave the fan on all the time for a month, then check and see if you can afford to leave it on.
> 
> Comfortwise, it is obvious that it is better to leave it on.
> 
> I'm going to find my multimeter and funky extension cord and get a reading on what it takes to run the fan.


But you also have to factor in
cycling of the burner/compressor, 
fuel use to comfort level, and life of the 
start windings to get the total picture.


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## Sam60

I must be the only one that consider it a waste of money to run 24 hours.
I did try it on a new unit I had for downstairs because it came with a 2 speed motor. So did not cost much to run and would filter the indoor air all the time.
But after a few years had to replace the blower motor at a cost of $550.00 for this Carrier model.


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## neolitic

rayh78 said:


> I must be the only one that consider it a waste of money to run 24 hours.
> I did try it on a new unit I had for downstairs because it came with a 2 speed motor. So did not cost much to run and would filter the indoor air all the time.
> But after a few years had to replace the blower motor at a cost of $550.00 for this Carrier model.


Funny my last one ran continuously 
for 15 years.
When the unit had to be replaced 
I saved the blower and motor and
I'm still using it as a dust collector 
in the shop.


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## Brock

neolitic said:


> Funny my last one ran continuously
> for 15 years.
> When the unit had to be replaced
> I saved the blower and motor and
> I'm still using it as a dust collector
> in the shop.


I would like a master electrician to chime in here.

Which costs me more to run annually.

1. My full size rfrigerator in the garage I use for beer and extra frozen food that doesn't fitin my indoor fridge.

-or-

2. Running my hvac fan all year.


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## MALCO.New.York

Well...........What is the Wattage of the Fridge/Freezer????

According to the following site, an "Upright" Freezer uses 3 times the amount of energy as a "Furnace Fan".


http://www.oksolar.com/technical/consumption.html


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## neolitic

Brock said:


> I would like a master electrician to chime in here.
> 
> Which costs me more to run annually.
> 
> 1. My full size rfrigerator in the garage I use for beer and extra frozen food that doesn't fitin my indoor fridge.
> 
> -or-
> 
> 2. Running my hvac fan all year.


Fidge by far and away.


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## threaderman

Excuse me if I seem ignorant but I haven't heard of this before.You're saying that if I'm not heating or cooling my home that my fan should always be running,and that it is not hard on the system but better than letting fresh air into the home,or do you let the fan run and keep doors and windows open as you normally would during mild weather?


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## neolitic

threaderman said:


> Excuse me if I seem ignorant but I haven't heard of this before.You're saying that if I'm not heating or cooling my home that my fan should always be running,and that it is not hard on the system but better than letting fresh air into the home,or do you let the fan run and keep doors and windows open as you normally would during mild weather?


How quaint.
That way I could actually find out 
if there are any non-obscene lyrics
that go with the thump-thump "music"
as the cars sit at the stop sign.
I could make a hobby of identifying
the subtle differences in the tones 
of each individual un-muffled motorcycle
engine.
Perhaps I might even learn to identify
the oil fields whence came the crude
by the nuances in the aroma of the 
diesel fumes.
Perhaps you are right, I should open those
windows to the gentle breeze more often.





Or not. :laughing:


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## threaderman

neolitic said:


> How quaint.
> That way I could actually find out
> if there are any non-obscene lyrics
> that go with the thump-thump "music"
> as the cars sit at the stop sign.
> I could make a hobby of identifying
> the subtle differences in the tones
> of each individual un-muffled motorcycle
> engine.
> Perhaps I might even learn to identify
> the oil fields whence came the crude
> by the nuances in the aroma of the
> diesel fumes.
> Perhaps you are right, I should open those
> windows to the gentle breeze more often.
> 
> 
> 
> 
> 
> Or not.


 What the hell are you talking about,I like fresh air,I've lived in some of the toughest cities out there and still kept my windows open,and am only trying to figure out what's best for my HVAC.Maybe you should move to a more calming place,Holy crap.


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## neolitic

threaderman said:


> What the hell are you talking about,I like fresh air,I've lived in some of the toughest cities out there and still kept my windows open,and am only trying to figure out what's best for my HVAC.Maybe you should move to a more calming place,Holy crap.


I didn't change, the city did.
I will take your advice and move
as soon as Mom dies.

As to the cost, my electric bill 
is lower than anyone I know.
Every time POCO figures my budget
payments, I cut them by 30% and
still come up with a balance in the
settle up month.
And I don't think it would hurt 
to move the air around the house
and through the filter even with
the windows open, maybe especially then.


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## delta l

*What??*

Do you run central air conditioning in the summer? If so, and you are in an area with high humidity, running a constant fan canl negatively affect your ability to dehumidify your home.

If your furnace/air handler is equipped with a variable speed motor, and depending on your thermostat, you can run an 'intermittent' fan which will allow the condensate to drain from your coil before running. Otherwise, it can be blown back into the air stream.

If chosen, mine will run 10 minutes on, 20 minutes off, if the stat has not called for cooling for an hour. Eliminates the stratification.

In wintertime, particularly if your unit is oversized and has a non-variable speed motor, running a fan w/o heat can cause a drafty, cold feeling.

It all depends on your system.

Delta


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## MALCO.New.York

delta l said:


> Do you run central air conditioning in the summer? If so, and you are in an area with high humidity, running a constant fan can negatively affect your ability to dehumidify your home.


Please explain..........With references.


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## neolitic

delta l said:


> Do you run central air conditioning in the summer? If so, and you are in an area with high humidity, *running a constant fan canl negatively affect your ability to dehumidify your home.*
> 
> If your furnace/air handler is equipped with a variable speed motor, and depending on your thermostat, *you can run an 'intermittent' fan which will allow the condensate to drain from your coil before running. Otherwise, it can be blown back into the air stream.*
> 
> If chosen, mine will run 10 minutes on, 20 minutes off, if the stat has not called for cooling for an hour. Eliminates the stratification.
> 
> In wintertime, particularly if your unit is oversized and has a non-variable speed motor, running a fan w/o heat can cause a drafty, cold feeling.
> 
> It all depends on your system.
> 
> Delta


You are called.
Citations, proof, back it up.
Both common sense and long experience
is in direct opposition to your claims.


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## Brock

delta l said:


> Do you run central air conditioning in the summer? If so, and you are in an area with high humidity, running a constant fan canl negatively affect your ability to dehumidify your home.
> 
> If your furnace/air handler is equipped with a variable speed motor, and depending on your thermostat, you can run an 'intermittent' fan which will allow the condensate to drain from your coil before running. Otherwise, it can be blown back into the air stream.
> 
> If chosen, mine will run 10 minutes on, 20 minutes off, if the stat has not called for cooling for an hour. Eliminates the stratification.
> 
> In wintertime, particularly if your unit is oversized and has a non-variable speed motor, running a fan w/o heat can cause a drafty, cold feeling.
> 
> It all depends on your system.
> 
> Delta


I thought the same thing until I tried it. The opposite of what you are saying actually occurrs with the fan on. I think it is because the heat rises and will stay closer to the ceiling level while it is cycled off. With the fan running all the time it is cycling the air and not allowing cool zones throughout the home. We also keep our ceiling fans on low most of the time to aid in pushing down the warm air.


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## MALCO.New.York

Brock said:


> We also keep our ceiling fans on low most of the time to aid in pushing down the warm air.



Down in the Summer. Up in the Winter. Try it!


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## neolitic

MALCO.New.York said:


> Down in the Summer. Up in the Winter. Try it!


Mmmmm, got your glasses on 
backwards. :laughing:
Warm air _down_ in winter.
Cold air_ up_ in summer.
Think about what you want 
to pool where, when. :thumbsup:


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## MALCO.New.York

So says you!

http://en.wikipedia.org/wiki/Ceiling_fan#Uses

http://www.spyfu.com/Term.aspx?t=281866


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## neolitic

MALCO.New.York said:


> So says you!
> 
> http://en.wikipedia.org/wiki/Ceiling_fan#Uses
> 
> http://www.spyfu.com/Term.aspx?t=281866


I don't live in Wiki-adia. :laughing:
What ever works for you, but 
what I said seems to work well with
cathedral ceilings, which is the most 
common habitat for ceiling fans hereabouts.


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## MALCO.New.York

The objective is to "reverse" the Natural tendencies of the Conditioned Air. 

Summer: Force the warmer air down so it can be Conditioned by the Cool air that is inherently "hugging the floor".

Winter: Draw the cooler air upward to be Conditioned by the Heated air that your furnace has created.

Ebb and Flow!


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## delta l

MALCO.New.York said:


> Please explain..........With references.


Perhaps my wording needs some clarity.

I don't have a reference handy, but from my following of HVAC/R forums, it has been the contention of the PROs that following a call for cooling, continued air circulation will cause the coil to gain heat and re-evaporate some of the condensate, which has not completely drained, i.e., wet coil.

While running the fan in this situation will help to mitigate stratification, allowing some fan time off will lessen re-evaporation of condensate.

Delta


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## MALCO.New.York

delta l said:


> Perhaps my wording needs some clarity.
> 
> I don't have a reference handy, but from my following of HVAC/R forums, it has been the contention of the PROs that following a call for cooling, continued air circulation will cause the coil to gain heat and re-evaporate some of the condensate, which has not completely drained, i.e., wet coil.
> 
> While running the fan in this situation will help to mitigate stratification, allowing some fan time off will lessen re-evaporation of condensate.
> 
> Delta


Disagree on ALL fronts! Just speaking from limited but well absorbed experience.


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## flashheatingand

Brock said:


> Do you recommend keeping the fan in the on position all year, or auto.
> 
> I have always been told it is better to leave it in the on position year round.


Based on the local rates electrical rates: .07/kwh
most residential fans use about 500watts (120 volts * 4.0 watts=480)
that comes to $.084/day or just over $300/ year.

Thats $300 a year with the fan on 24/7. If left on auto you would consume about 1/3 the amount power. So, you are spending roughly 200/year to run the fan 24/7 Thats the economic side of the question.

As for comfort and "air cleaning" 24/ 7 is better, but, usually the fan runs at high speed while in the "on" mode. When the heat kicks in, the fan will run a a lower speed. It is hard on the motor to change speeds from high to low. If the furnace short cycles the fan changes speed several times an hour which can shorten the life of a blower.

I would just leave the fan at auto, but, there are applications which on 24/7 is better.


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## Brock

flashheatingand said:


> Based on the local rates electrical rates: .07/kwh
> most residential fans use about 500watts (120 volts * 4.0 watts=480)
> that comes to $.084/day or just over $300/ year.
> 
> Thats $300 a year with the fan on 24/7. If left on auto you would consume about 1/3 the amount power. So, you are spending roughly 200/year to run the fan 24/7 Thats the economic side of the question.
> 
> As for comfort and "air cleaning" 24/ 7 is better, but, usually the fan runs at high speed while in the "on" mode. When the heat kicks in, the fan will run a a lower speed. It is hard on the motor to change speeds from high to low. If the furnace short cycles the fan changes speed several times an hour which can shorten the life of a blower.
> 
> 
> You mean $30.00 (thirty dollars) per year. .084 x 365 days equals $30.66
> 
> Compared to about $10.00 with the fan on auto cycle.
> 
> I would rethink it if I was handing out 200 bones extra per year. I'm not that much into health and comfort.


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## flashheatingand

Sorry, I was off with the decimal points, I meant 84 cents a day. Which comes out to be about three hundred dollars a year.

.07/kwh. Fan uses .5 kw/hr. Doing the math it would come out to .84/day. (.5*.07)*24=.84... We have some good electric rates compared to the rest of the country. You should do the math for your location. The bigger the air handler, the higher the wattage, but, with most residential furnaces, the fan draws about 1/2 a kw.

Just out of curiosity, how much do you pay for electricity in the mid-west?


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## Brock

flashheatingand said:


> Sorry, I was off with the decimal points, I meant 84 cents a day. Which comes out to be about three hundred dollars a year.
> 
> .07/kwh. Fan uses .5 kw/hr. Doing the math it would come out to .84/day. (.5*.07)*24=.84... We have some good electric rates compared to the rest of the country. You should do the math for your location. The bigger the air handler, the higher the wattage, but, with most residential furnaces, the fan draws about 1/2 a kw.
> 
> Just out of curiosity, how much do you pay for electricity in the mid-west?


I should know this, but I haven't looked at the paper bill in a long time. The average for my 3000 sq. ft home is about $100.00 per month. We heat with natural gas though and that bill runs about the same if averaged out over the year maybe a little less than $100.00 because the H/W tank is on gas.


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## Texwing

Welllll, i sense I should stay out of it but....the value of running the fan ON all the time would depend on many factors. Having done some advanced research on duct losses, it would be interesting to know, in Southern climes with 130 degree attics and shoddy flexible ducting systems, undersized returns, and leaks everywhere, does running the fan in the "on" position provide more harm than benefit? In other words, if you take in the reality of the typical southern attic duct system, increase its operation by 70%, and then figure out the increased duct losses, infiltration, humidity load, and so on, what you find? So, blanket statements as to whether "ON" is good or bad may need to be a little more specific to location, system, and home style.
Just my two cents worth.


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## Dr Heat

Texwing said:


> Welllll, i sense I should stay out of it but....the value of running the fan ON all the time would depend on many factors. Having done some advanced research on duct losses, it would be interesting to know, in Southern climes with 130 degree attics and shoddy flexible ducting systems, undersized returns, and leaks everywhere, does running the fan in the "on" position provide more harm than benefit? In other words, if you take in the reality of the typical southern attic duct system, increase its operation by 70%, and then figure out the increased duct losses, infiltration, humidity load, and so on, what you find? So, blanket statements as to whether "ON" is good or bad may need to be a little more specific to location, system, and home style.
> Just my two cents worth.



Now that two cents is worth 40 bucks :notworthywell said. Other thoughts do you have oa intake are the ducts properly sized are you running an eac perhaps a true steam does your furnace have a constant fan tap? Ask your tech. when he comes to service your furnace.


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