Variable speed and continuous fan

[geoss54]

Hi,
Haven't been here for a while. have 1 question. I have the Infinity system with the 96% eff. furnace. Live in a 2 story townhouse. What is the general opinion about running the variable speed fan on low all the time vs. the auto mode. Is there a benefit in the winter? The system is default set at Comfort for both furnace and a/c. But I have the fan running on low. I also have an EAC, with the pre filter and the post filter(Honeywell).
Oh yes, are the post filters really worth keeping in?
thanks
George

[oldertech]

Running the fan continuously has the benefit of reducing the temperature differences between floors and cleaner air.

If your family doesn't suffer from asthma or allergies the benefit of cleaner air may not outweigh the additional cost.

For myself, without those conditions, I would not run the fan continuously.

If your post filters are charcoal their purpose is to absorb odors. You decide if you need that.

[hvaclogic]

Continous low in winter and continous medium or high in summer. Keeps the air cleaner and keeps the temps in the home level through out.

[geoss54]

thanks for input.
Is there a way to "lower" the low speed on the continuous operation. When running there is cool air coming out of the supply. Thanks
George

[heetseeker]

If you run constant fan in the winter check if your humidifier is running constantly with a constant drain of water. This may happen especially in very cold weather since the humidifier may have trouble keeeping up the humidity.
In the summer, constant fan will keep your humidity higher than when set on auto since the fan will re-evaporate the moisture that just condensed on the coil.

[geoss54]

we do not have a humidifier in the house. my wife and I have not noticed excessive dryness in the house so far.

[hvaclogic]

thanks for input.
Is there a way to "lower" the low speed on the continuous operation. When running there is cool air coming out of the supply. Thanks
George



Have your installer check to make sure that the cfm selection is correct for you system. He can change the cfm setting for cooling and make a seperate change for continous fan.

As far as continous fan in the summer making the house more humid that will depend on the level of equipment that you have. Carrier does recommend a continous fan in the summer. Hope this helps.

[heatpumpguru]

George ,call Joe or sevice they should have fan on lowest speed in ON mode,you can change it at the Infinity control,I think that is as low as in goes. Call you got the warranty!!John

[oldertech]

The continuous fan setting is the fan button on the side of the UI at top left. Auto, low, med, high.
That setting effects the continuous fan setting only.
During a call for heat or cool fan operates as needed as the system decides.

Just noticed you didn't mention whether or not you also have the infinity user interface (thermostat).
The above assumes you do.

[Airmechanical]

Continous low in winter and continous medium or high in summer. Keeps the air cleaner and keeps the temps in the home level through out.


also continuous in the summer makes you house very humid!



.

[dash]

also continuous in the summer makes you house very humid!



.

Infinity can be setup to drain the coil with an offcycle ,to negate that.

[seatonheating]

Infinity can be setup to drain the coil with an offcycle ,to negate that.


Wow, I didn't know that, that's pretty sweet. I would think the "circ" mode on the visionpros would be adequate for the summertime. Maybe I should change what I tell my customers?

[geoss54]

Hi,
Yes I do have the Infinity control thermostat and I have fan set to Low. Tried Auto for a few days but didn't feel right....
To negate ther humidity from the coil in the summer someone said this: "Infinity can be setup to drain the coil with an offcycle ,to negate that."
HOw would this be set up from the thermostat-which settings are they? Thanks
George
p.s. Hi John.......
__________________

[oldertech]

Hi,
Yes I do have the Infinity control thermostat and I have fan set to Low. Tried Auto for a few days but didn't feel right....
To negate ther humidity from the coil in the summer someone said this: "Infinity can be setup to drain the coil with an offcycle ,to negate that."
HOw would this be set up from the thermostat-which settings are they? Thanks
George
p.s. Hi John.......
__________________

Are you wanting to run the blower slower than low? I don't think that's possible.

Drain coil during off cycle? Boy, thats a new one. There are so many settings on that.....
Yeah you can!

Install the coil with proper level.........lol jk

[oldertech]

Infinity can be setup to drain the coil with an off cycle ,to negate that.

Please educate me.

[dash]

on the off cycle,the fan stops for a few minutes to let the coil and drain(pan has a nice internal slope) drain ,then restarts.

Though the coil will still be wet ,it's an improvement for those you want/need the fan 24/7.

With air handlers and their negative coil pressure ,big improvement to not hold an inch of water in the pan.

[oldertech]

on the off cycle,the fan stops for a few minutes to let the coil and drain(pan has a nice internal slope) drain ,then restarts.

Though the coil will still be wet ,it's an improvement for those you want/need the fan 24/7.

With air handlers and their negative coil pressure ,big improvement to not hold an inch of water in the pan.

Where is that found in the setup?

We don't have the humidity problem in so cal that requires that.

I love this hvactalk. There is so much to learn from professionals across the country.

[geoss54]

Hi,
Yes, I would like to know where that is found on the Infinity control thermostat, or is it a default setting, or a setting that can be increased.......I seem to have seen some setting while going through the thermopstat that had 120 seconds????George

[Airmechanical]

on the off cycle,the fan stops for a few minutes to let the coil and drain(pan has a nice internal slope) drain ,then restarts.Though the coil will still be wet ,it's an improvement for those you want/need the fan 24/7.



back to post #10

it will make your house humid!:rolleyes:



.

[geoss54]

this is the setting I was talking about....what is the ideal setting-the default or higher............

OFF DELAY:
• 90 seconds (default)
• 120 seconds
• 150 seconds
• 180 seconds
Amount of time the blower will continue to run after heating has
shut off.

[oldertech]

this is the setting I was talking about....what is the ideal setting-the default or higher............

OFF DELAY:
• 90 seconds (default)
• 120 seconds
• 150 seconds
• 180 seconds
Amount of time the blower will continue to run after heating has
shut off.

Default is what was used during efficiency and operation certification. Don't try to second guess.

Higher will get more heat or cooled air into the house if there is any more residual but use more electricity. So, do you want to do the math calculating how much you might save or spend by changing the default?
Not me.

[oldertech]

Where is that found in the setup?

We don't have the humidity problem in so cal that requires that.

I love this hvactalk. There is so much to learn from professionals across the country.

Waiting

[hvaclogic]

back to post #10

it will make your house humid!:rolleyes:



.

If you set up your UI correctly,i.e the cooling humidity percentage then the humidity will be kept to a minimum. If it senses the humidity starting to rise then cooling will be initiated with a low fan speed to reduce the humidity.

While it is true that running generic equipment with continous high speed fan can cause the condensate in drain pan to evaporate and possibly raise humidity the Infinity control was designed to address these issues. Thats why you got the Infinity in the first place, right? Total comfort! Otherwise you would have just went with a T87F and called it good.


Carrier! Turn to the Experts.:D

[geoss54]

It is an Infinity system-it is a great install.......so I guess what the consensus is to leave default settings for Comfort and let the equipment do its work....and with v/s fan set at low continuous?
George

[Airmechanical]

If it senses the humidity starting to rise then cooling will be initiated with a low fan speed to reduce the humidity.


obviously the humidity is going to rise in the house every time the condenser cycles off

(atleast until the infinity coil totally dries and drain pan is totally dry)

so here is whats happening, on the off cycle your infinity pumps humidity

back into your house, (ok but not as much humidity as a non infinity system)

then when your infinity realizes it has pumped too much humidity back into

your house the infinity turns the compressor on to remove the humidity back out

that it just pumped in, its probably more comfortable and keeps a better average temp.

but it uses more electricity than some people may realize to run your fan on continuous,

because its not just the extra power required to operate the fan motor,

you are basically putting your system in a pump humidity in and a pump humidity out circle!



.

[oldertech]

on the off cycle,the fan stops for a few minutes to let the coil and drain(pan has a nice internal slope) drain ,then restarts.

Though the coil will still be wet ,it's an improvement for those you want/need the fan 24/7.

With air handlers and their negative coil pressure ,big improvement to not hold an inch of water in the pan.

Okay dash, no response yet. Do you know how to set up the infinity to stop the fan during off cycle for a few minutes so the coil can drain, even though it's set for continuous fan??
I guess you don't, and my educated guess is that it is not possible.

dash, if you admit you don't know or was mistaken some of your pride may be salvaged.

[orlandotech]

Okay dash, no response yet. Do you know how to set up the infinity to stop the fan during off cycle for a few minutes so the coil can drain, even though it's set for continuous fan??
I guess you don't, and my educated guess is that it is not possible.

dash, if you admit you don't know or was mistaken some of your pride may be salvaged.

It sometimes takes him awhile to respond back. I asked him about some van shelves he advertised in the junkyard and he never responded back. just wait a little. I'm curious too.

[hvaclogic]

obviously the humidity is going to rise in the house every time the condenser cycles off

(atleast until the infinity coil totally dries and drain pan is totally dry)

so here is whats happening, on the off cycle your infinity pumps humidity

back into your house, (ok but not as much humidity as a non infinity system)

then when your infinity realizes it has pumped too much humidity back into

your house the infinity turns the compressor on to remove the humidity back out

that it just pumped in, its probably more comfortable and keeps a better average temp.

but it uses more electricity than some people may realize to run your fan on continuous,

because its not just the extra power required to operate the fan motor,

you are basically putting your system in a pump humidity in and a pump humidity out circle!



.



How many of your customers have the Infinity control? I would guess that number to be ZERO!

[Airmechanical]

How many of your customers have the Infinity control? I would guess that number to be ZERO!

is that all you got dude!

boy that is pretty logical ---not



.

[hvaclogic]

is that all you got dude!

boy that is pretty logical ---not



.


What more do I need? Dude! You still didn't answer the question did you?

Aren't you strictly commercial? I'm just curious how many grocery and c-stores use the Infinity control?

I am a Carrier Factory Authorized Dealer. We had four Infinity systems presold before the Factory even rolled out the Infinity line. I have several of the Infinity systems installed and performing beautifully. Maybe you have "seen" one or two but I have installed hundreds.

You want to spllit hairs on cost of continous fan run directly related to humidity run times? Ok, I'll concede to your obvious superiority on the matter of Infinity controls (not). So the HO only saves $98.00 instead of $100.00. Truth is the new system is saving the HO more money over his old system so he is willing to give up a percent or two of potential savings for a more comfortable home enviroment, isn't that why the HO bought the best to begin with?

[oldertech]

It sometimes takes him awhile to respond back. I asked him about some van shelves he advertised in the junkyard and he never responded back. just wait a little. I'm curious too.

Alright, thanks.

[geoss54]

Under continuous fan on low, the Infinity control reads:

450cfm airflow

517 blower rpm


0.20 static pressure

How does this look?

with the post filters out, the #'s are:
450
485
0.17

George

[Airmechanical]

I am a Carrier Factory Authorized Dealer. Maybe you have "seen" one or two but I have installed hundreds.You want to spllit hairs on cost of continous fan run directly related to humidity run times?

look chief, l will agree you are a leading member of the infinity fan club,

i would not even disagree if you said your last name was carrier!

and with your hundreds of installs you alone have made carrier famous,

i guess carrier and you have reinvented the wheel with the infinity system,

and still the fact still remains as originally stated by me,

(when running fan on continuous in the cooling mode humidity is being pumped into the house during the off cycle)

and that is not splitting hairs!

yes you are honestly a better infinity tech. than i am, but you cant change physics!



.

[hvaclogic]

Willis Carrier is my grandfather and it was my idea to come up with the Infinity control. :p

[hvaclogic]

You can't change physics but you can change your mind.;)

[davo]

I install over 100 infinity systems per year in SW FL. HOT and HUMID
You are correct, as with any mechanical refrigeration system, running the fan in continuous mode will increase the space Rh. This happens due to re-evaporation of moisture from the drain pan and coil, but primarily due to increased infiltration caused by duct leakage. The difference is, the infinity is designed to minimize these effects, and handle the moisture and maintain a relatively constant Rh. If you have a need for increased filtration, the cost increase to operate the equipment to do this is well worth it.

[Airmechanical]

I install over 100 infinity systems per year in SW FL. HOT and HUMID,You are correct, as with any mechanical refrigeration system, running the fan in continuous mode will increase the space Rh. This happens due to re-evaporation of moisture from the drain pan and coil, but primarily due to increased infiltration caused by duct leakage.


thank-you, i am glad an infinity spokesman finally admitted it!

and i admit the infinity has some awsome controls,

hold on trane and goodman just e-mailed me!:D



.

[davo]

also continuous in the summer makes you house very humid!



.
Your quote says running the fan in continuous will make the house very humid.

The infinity controls can sense that and compensate, maintaining a relatively constant Rh. Just splitting hairs with you as you are with the other infinity guys.

Yes, it does cost extra money in electric to do this. I notice about a $8.00/month increase in my electric bill due to running the fan continuous in my home on my 3 ton infinity system. Well worth the expense for me as I have asthma and allergies.

I choose the best trade for my medical conditions!

[Airmechanical]

Your quote says running the fan in continuous will make the house (very) humid.Just splitting hairs with you as you are with the other infinity guys.Yes, it does cost extra money in electric to do this



ok the hairs have been split i stand corrected, my official (new statement is)

with an infinity system your house will gain humidity

when running fan on continuous in the off cycle!

there is that better? notice i left out "very humid"

now lets argue about something else!


.

[jeffw_00]

I don't want to argue with the experts, all I am is a HO with an Evolution A/C system who has (i think) thoroughly read all the docs (including service docs). I would suggest....

1) contrary to popular myth, there is no way to dial-in CFM for different fan settings

2) If the house is at temp but above humid setting, system will NOT perform extra cooling to reduce humidity. There is a setting that will make it do this: When house is above temp and above humid, it will initially do more cooling at low-speed to try to get humidity down as it cools

Now here's a question for you: I live in new england, my A/C system is in the attic. (my furnace is in the basement on a different duct system). I get some condensation in the un-insulated parts of my A/C duct system in the winter (like: around the grilles, inside the filter cabinet). Would setting my A/C system to periodically run the fan in the winter do me any good to reduce the condensation? (closing all the grilles is a bit problematic, though I might be able to close 95% if I get that magnetic stuff).

thanks
/j

PS - I run the fan on medium all summer - primarly to cycle all the air through the filter. I've done some experiments with this on vs. off and on (especially overnight) does wonders for my allergies. FWIW, my house is comfortably dry nevertheless. However, due to this thread, I will try running the fan on my evolution furnace on LOW and see if that makes the house (even) more comfortable...

[geoss54]

Hello,
Do my system readings seem o.k.(post #32), to have the fan continuous low. Not too taxing on the motor wityh those numbers?
Thanks
George

[hvaclogic]

Hello,
Do my system readings seem o.k.(post #32), to have the fan continuous low. Not too taxing on the motor wityh those numbers?
Thanks
George


You're good to go chief. Enjoy the quality system that you have. Many are and will be envious.:D

[lra]

Away from the comfort issue for a moment. When does a light bulb blow ? When you turn it on. Hardest thing on an electrical load is starting and stopping. They were designed for continous operation. Continuous operation is recommended. Run it. I've never changed a defective variable speed motor... but lots of variable speed modules.:eek:

[geoss54]

Really appreciate everyone's responses-this is the best ,and most informative forum.
To finish, does anyone see any negative effect if I put in one more return(it would be a 6" high return in my L.R., because it gets strong sun in the mornings, and presently there is a 6" in the floor. I am not worrying about having enough all around(I do), but would like to get some higher circulation in that room. Any negatives forseen? It would be about13 ft run into the return plenum.
Thanks
George
p.s. I guess what I'm asking is if it could hurt? and possibly even help?

[orlandotech]

2) If the house is at temp but above humid setting, system will NOT perform extra cooling to reduce humidity. There is a setting that will make it do this: When house is above temp and above humid, it will initially do more cooling at low-speed to try to get humidity down as it cools

it's been awhile since I set one of these up so if I am wrong, this is from memory:
On a thermidistat it is called " cool to dehumidify ". It is accessed by pushing the humidity button. under dhu push mode until you see " cool " next to the RH setpoint. then it will cool in low speed up to 3 degrees below cooling setpoint in an effort to lower RH. otherwise it would not call to lower RH if the space setpoint is satisfied. Rh setpoint takes a little more priority over space setpoint in this mode.

[jlawren2324]

FIY regarding humidity etc.and its operation FIY everyone I Will Super dehumidify with no cool demand but.....there is a glitch in ver10.0.
If the user turns sys off whike in super dehum,the outdoor unit could continue to run by it self. There are a few hoops the homeowner can do but we have simply been issued the new ver 12.0 which will be written on the box. So I think I saw someone who thought it would no super dehum, it sure does so that brought this 1 of many DSB items to mind

[orlandotech]

ok the hairs have been split i stand corrected, my official (new statement is)

with an infinity system your house will gain humidity

when running fan on continuous in the off cycle!

there is that better? notice i left out "very humid"

now lets argue about something else!


.

any system will do that during cool off cycle, not just infinity. ;)

sorry dude, hadta happen.:D :D

[jlawren2324]

I believe it was orlandotech who got my attention . The Thermidistat did do the same thing The Infinity is factory default for this,

[jeffw_00]

orlandotech - I don't think the Evolution control doesn't do this. all I find in the manual is an option to increase airflow to reduce duct sweating.

[geoss54]

How about my extra return in my L.R. question. Thanks
George

[orlandotech]

How about my extra return in my L.R. question. Thanks
George

IMO, there is no such thing as too much return.
in centrl. fla they make us either install ducted returns in every bedroom or a " return transfer " which is a return flex that vents excess air from the bedroom to a common area like a hallway or a living area when the door is shut. the old way was relying on the door undercuts ( gap between bottom door edge and floor ) but I guess with some flooring products it would clog that up and restrict the airflow. air in is air out. if the air can't get out you won't get any fresh cold air in. but to get back to you question, go for it.

[orlandotech]

orlandotech - I don't think the Evolution control doesn't do this. all I find in the manual is an option to increase airflow to reduce duct sweating.

it might be part of the installers setup. I'm not familiar with that control system. sorry. I would think it has the option available though. it might be a special buttonpush sequence to get into it ( i.e. on thermidistat you have to push both up and down buttons to check outdoor temp and inside RH ).

[dash]

Okay dash, no response yet. Do you know how to set up the infinity to stop the fan during off cycle for a few minutes so the coil can drain, even though it's set for continuous fan??
I guess you don't, and my educated guess is that it is not possible.

dash, if you admit you don't know or was mistaken some of your pride may be salvaged.



Strong words there,but you may be correct.Might be in the next version as I sat in on a meeting concerning it.

Could also be Big Blue from white rogers.

I don't see a provision looking in the install manual,so I give,total loss of pridee ,you are right.

However ,lots of the hundreds of customers that we installed for ,run the fan 24? on low,which drops the static and lets the pan drain,no compliants,just raves in the thank you letters!

[dash]

Yes Infinity and Thermidistat will cool to dehum. if setup that way.

[dash]

It sometimes takes him awhile to respond back. I asked him about some van shelves he advertised in the junkyard and he never responded back. just wait a little. I'm curious too.



Sorry about that orlando,$25 per section if you are still interested.

[orlandotech]

Sorry about that orlando,$25 per section if you are still interested.

no prob dash.
will they fit a '97 ford e250? how long are they? do you happen to have a pic of them?

[oldertech]

Strong words there,but you may be correct.Might be in the next version as I sat in on a meeting concerning it.

Could also be Big Blue from white rogers.

I don't see a provision looking in the install manual,so I give,total loss of pridee ,you are right.

However ,lots of the hundreds of customers that we installed for ,run the fan 24? on low,which drops the static and lets the pan drain,no compliants,just raves in the thank you letters!

Thanks dash.

As it was pointed out to me, you sometimes take a while to answer.

I don't know you and I'm new here. It's so easy to be a posser.......

Well, thanks for the answer.

[jeffw_00]

it might be part of the installers setup. I'm not familiar with that control system. sorry. I would think it has the option available though. it might be a special buttonpush sequence to get into it ( i.e. on thermidistat you have to push both up and down buttons to check outdoor temp and inside RH ).

I was looking through the installers manual. I never used their older thermidistat module but I get the sense it was more flexible than the evolution control.

[dash]

No just more complicated.

[geoss54]

In my previous home I had a Thermidistat and I know about the Cool to Dehumidify setting, but where is it in my present system, ther Infinity Thermostat?
Thanks
George

[dash]

no prob dash.
will they fit a '97 ford e250? how long are they? do you happen to have a pic of them?

They'll fit .approx. 3 feet each.No pics but i'll see aabout that

[oldertech]

In my previous home I had a Thermidistat and I know about the Cool to Dehumidify setting, but where is it in my present system, the Infinity Thermostat?
Thanks
George

The Infinity is set by default to cool-to-dehumidify. In the advanced advanced menu it's called comfort. In contrast to maximum or efficiency.

[oldertech]

Yes Infinity and Thermidistat will cool to dehum. if setup that way.

Infinity is set to cool to dehum by default.

[geoss54]

O.K. Thanks..That's what I have both furnace and a/c set to: Comfort.
George
p.s.(as always)
I have the Honeywell EAC with the turquoise colored post filters. Even though fan is continuous, they hardly have anything on them.When I put them in, the static goes from 0.17 to 0.21 when on low continuopous fan.
Question is, are they worth leaving in, or is the reduced static better for my system?

[orlandotech]

They'll fit .approx. 3 feet each.No pics but i'll see aabout that

thanks man. I have to get with the boss and see if he wants to buy them. I need some more bin space in the van. they sound cheap enough though. my email is in the profile.

[oldertech]

O.K. Thanks..That's what I have both furnace and a/c set to: Comfort.
George
p.s.(as always)
I have the Honeywell EAC with the turquoise colored post filters. Even though fan is continuous, they hardly have anything on them.When I put them in, the static goes from 0.17 to 0.21 when on low continuopous fan.
Question is, are they worth leaving in, or is the reduced static better for my system?

All the post filters I have seen are carbon which only remove odors.

If you have that much static at low speed, at high it would probably be too much static.

I say take it out durning AC season or always, it's up to you.

[geoss54]

It is the new Honeywell EAC with the electrostatic post filters.......anyway just checked the static with continuous fan on High, and static was 0.70 without the filters.
Do you think adding one more return lowers the static???just curious. Thanks
George

[dash]

Infinity is set to cool to dehum by default.


Or it's not.

Could have been changed

[oldertech]

SYSTXCCUID01--A
AC AIRFLOW:
• COMFORT (default)
• EFFICIENCY
• MAXIMUM
Selects the airflow of the furnace when cooling. COMFORT is a
decreased airflow used to improve humidity control. EFFICIENCY
is the airflow used to meet specified ratings. MAXIMUM
is a fixed airflow speed of 400 CFM/ton based on the
outdoor unit size.

DEHUM AIRFLOW
NORMAL (factory default) -- When equipment is
running to dehumidify, the airflow is allowed to adjust
to a minimum to satisfy the dehumidification call.
HIGH -- Minimum airflow during the dehumidify
mode is increased to reduce duct and register sweating.

SYSTXCCUIZ01--A
AC AIRFLOW
COMFORT (default) -- cooling airflow is varied
depending on humidity and temperature demands
settings. This selection enables the full dehumidify and
comfort capabilities of the system. When COMFORT
is not selected, the unit will not run reduced aiflows for
dehumidification.

The above pasted from installation instructions for the 2 infinity controls listed on Carrier's web site.

If it has changed it's not posted on their website yet.

[jeffw_00]

yup - that's what I saw. There isn't a specific setting that, when enabled, causes it to continue to dehumidify when the cooling temp is reached. Still, I used mine last summer in the default settings and it did a fine job dehumidifying (I know, because my old system had a habit of cooling before it dehumidified)

[oldertech]

The default comfort setting may, I say may allow overcooling. That is to say room temp would drop below setpoint while trying to dehumidify.

Have you experienced that?
I had a customer who complained of this overcooling while in comfort setting.

[dash]

Or it's not.

Could have been changed

Could have been changed from the default setting,we do it often as some customers don't want to see it over cool.

[dash]

They can definately coolto dehum.,which will over cool.

[oldertech]

Could have been changed from the default setting,we do it often as some customers don't want to see it over cool.

Oh, I misunderstood your post dash. It sounded like you were saying the infinity default could have changed.

Agree, I have changed the setting myself for that reason.

[geoss54]

That's what my settings are....will keep a closer eye on the overcooling issue this summer-didn't pay much attention last summer(system was new), and we wewre out alot.
Will add that extra duct in L.R. high up on the wall, but kinda restricted in space so have to use a 6" flex(possible could fit a 7"), but I suppose can't hurt. Thanks
George