Bryant Evolution Fan Speed Issue?

[Sam23]

I have a Bryant furnace/AC system with variable speed fan and a Evolution thermostat. My question concerns the fan speed when the furnace is operating. The system seems to do fine maintaining a temperature - fan runs at low speed. The problems start if you adjust the temp up by as little as one degree - the fan jumps to medium and right to hurricane force. Its noisy and there' so much heat coming out that it feels oppressive and heavy. Makes it almost impossible to use the daily temp programming functions because it gets so uncomfortable.

Is there a way to prevent it from going to this super hi-speed setting? I say super hi-speed because its higher than the system ever runs AC mode during the summer. I wish it would run that high on AC so it could keep up with the cooling better.

Any tips would greatly apprectated.

-dave

[dash]

Sounds like the duct system may be on the small side.

Some adjustment to cfms may be possible,or it may already be as low as possible for high speed.

Posting all models numbers would be helpful,as well as pics of the furnace and connecting ducts.

[saylor240]

the Motherboard may be set up wrong, call your service company, many boards are universal and have to be set up by a factory tech or you will get to many CFM for your duct, also DASH is right if your duct is to small, like say you used to have a old oil burner and small ducts it will sound as if you have a frieght train going thru your house, variable speed fans are great if duct is sized right and board is set up right, my trane variable speed is running, heat or a/c you can barley hear it, but i set up more return and increased duct size. if not i would have had same issue.

[tedkidd]

You can control everything at the stat. Changing dips on motherboard will do nothing, the stat overrides all that stuff. Wonderful thing about communicating, change a whole bunch of things without touching wires or dips.

Keep notes about the things that bother you so someone who knows how to program the stat can tailor the settings to meet your needs. Have your co send out someone familiar with setting that stat up.

Does sound over sized for your house if low is maintaining at the temps we've had on low (country wide temps are LOW). If Medium or high feels like "hurricane force" your fan, and therefore furnace, may be way too big for your duct work. Both problems represent energy and longevity issues. Was a heat load performed?

My Infinity (Evolution) customers indicate on high fan their new equipment is much quieter than their old equipment.

[Sam23]

Here are the model numbers/info that I have:

80% 15 Seer Variable 410A
Furnace 315AAV036070
Evaporator Coil CNPH3617ATA
Ac Condensing Unit 165ANA030000
Evolution Thermostat

This was a new install by a local dealer that has since folded, but had been in business for a number of years. Only have this problem in heat mode. The fan dosen't operate at this RPM level, in cool mode, even on the hotest days and usually has trouble maintaining temperature in the late afternoon. It almost seems like there are four speeds. That or the AC never kicks in the fan into high, but the furnace has no problem jumping to it at the drop of a hat.

Could that happen - the fan is switching to high speed only in heat mode and not cool?

Changing the fan speed on the thermostat from Auto to a lower speed dosen't seem to have any effect, even when I change it in the advanced setup.

[tedkidd]

I'd recommend finding a Carrier or Bryant dealer for service. Should have service every 1-2 years anyway. Sounds like you've had it long enough that it'd be time. Have them send someone who knows the system.

I can't tell you how to get to programming mode - but the install manual will. Be better to have a service guy show you.

[commerce48]

I have a Bryant furnace/AC system with variable speed fan and a Evolution thermostat. My question concerns the fan speed when the furnace is operating. The system seems to do fine maintaining a temperature - fan runs at low speed. The problems start if you adjust the temp up by as little as one degree - the fan jumps to medium and right to hurricane force. Its noisy and there' so much heat coming out that it feels oppressive and heavy. Makes it almost impossible to use the daily temp programming functions because it gets so uncomfortable.

Is there a way to prevent it from going to this super hi-speed setting? I say super hi-speed because its higher than the system ever runs AC mode during the summer. I wish it would run that high on AC so it could keep up with the cooling better.

Any tips would greatly apprectated.

-dave

You can force it to low stage only at the stat. That should fix those symptoms when you bump it up a degree. Not a total fix in that your furnace in low stage will probably not (should not) keep up on the coldest days (but you can change it back manually on those days). There is some issue(s) that needs to be addressed, including duct sizing.

[Sam23]

You can force it to low stage only at the stat. That should fix those symptoms when you bump it up a degree. Not a total fix in that your furnace in low stage will probably not (should not) keep up on the coldest days (but you can change it back manually on those days). There is some issue(s) that needs to be addressed, including duct sizing.

That's what I want to do for now, but I don't know how. Changing the fan speed on the thermostat doesn't change anything. I'm assuming there's something I can set, but I don't know what it is?

[commerce48]

That's what I want to do for now, but I don't know how. Changing the fan speed on the thermostat doesn't change anything. I'm assuming there's something I can set, but I don't know what it is?

I don't have one of these furnaces, however if you look at your manual, there are instructions. Hopefully it is in your user manual for the stat, a tech showed it to me. Could have been their manual I suppose, but he showed it to me to demonstrate that it was under home owner control.

[Luke Duke]

The fan setting at the top right corner is only for continuous fan operation and has nothing to do with the fan speed during a call for heat or a/c. You should probably just keep that in low. I install carrier infinity which is basically the same thing as the evolution, you can do alot with those controls. Go to the advanced setup and check the airflow settings for the furnace and a/c. See if the furnace is on maximum, try the comfort setting for the furnace airflow and see if that makes it better, it should. If your ducts are under sized and your static pressure is high then that comfort setting will probably make the furnace lock out on limit from overheating. Then you have alot bigger problem. Usually the furnace has a 10 minute high stage delay unless you raise the temp by 3 degrees or more. You could also set the furnace airflow to efficiency instead of maximum. The infinity and evolution control are great stats and you can configure your system many ways. The installers probably had no idea what the were doing.

[tedkidd]

The fan setting at the top right corner is only for continuous fan operation and has nothing to do with the fan speed during a call for heat or a/c. You should probably just keep that in low. I install carrier infinity which is basically the same thing as the evolution, you can do alot with those controls. Go to the advanced setup and check the airflow settings for the furnace and a/c. See if the furnace is on maximum, try the comfort setting for the furnace airflow and see if that makes it better, it should. If your ducts are under sized and your static pressure is high then that comfort setting will probably make the furnace lock out on limit from overheating. Then you have alot bigger problem. Usually the furnace has a 10 minute high stage delay unless you raise the temp by 3 degrees or more. You could also set the furnace airflow to efficiency instead of maximum. The infinity and evolution control are great stats and you can configure your system many ways. The installers probably had no idea what the were doing.

Run the startup test - it'll tell static on low, med, and high. Then you'll know if your furnace is too big for your duct work. That controller will tie your shoes too!

[lancerbomb08]

those evolution systems are pretty sweet....i dont know if theyve come out with anything better but are they still pretty high end or have they been passed up yet? havent been in residential in a few years

[Sam23]

The fan setting at the top right corner is only for continuous fan operation and has nothing to do with the fan speed during a call for heat or a/c. You should probably just keep that in low. I install carrier infinity which is basically the same thing as the evolution, you can do alot with those controls. Go to the advanced setup and check the airflow settings for the furnace and a/c. See if the furnace is on maximum, try the comfort setting for the furnace airflow and see if that makes it better, it should. If your ducts are under sized and your static pressure is high then that comfort setting will probably make the furnace lock out on limit from overheating. Then you have alot bigger problem. Usually the furnace has a 10 minute high stage delay unless you raise the temp by 3 degrees or more. You could also set the furnace airflow to efficiency instead of maximum. The infinity and evolution control are great stats and you can configure your system many ways. The installers probably had no idea what the were doing.

Thanks, I'll check this evening to see how its set and try what you suggest.

[Sam23]

Run the startup test - it'll tell static on low, med, and high. Then you'll know if your furnace is too big for your duct work. That controller will tie your shoes too!

Will do. Is the startup test on the advanced menu?