Carrier Infinity- Fan Makes Too Much Noise on High Speed-Can it be adjusted?

[beenthere]

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Both returns join together just above the furnace and it comes in at the bottom side of the furnace.
Gary

Post pic. Your return attachment may be some of your noise problem.

[hvacrmedic]

The programmable fan feature is set to OFF by default in the dealer setup menu. Have your dealer turn this feature on. This will allow you to set up a schedule for the fan per Homeowner's Guide instructions.

Can you post an audio recording of the noise?

[motoguy128]

Yes, sorry, I forgot to mention it. Yes, the 'comfort' setting is selected. Is this a good thing to have them selected?.....
Gary

Then thery might be able to try minium setting. In the manual it specifically mentions using this if duct noise is an issue. Id still try a couple better grills in ome room to see if it helps. It made a huge improvmemt in my home.



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[goddi]

Greetings All,
I will have to see if I can get a picture or audio of the noise. Give me some time for that.
However, I did a few other things to see what might be affecting the noise when the fan is on HIGH speed. I took out the 4" filter and the noise (more of a harmonic hum) went away. I then put in a somewhat used E-Z filter that I have and the noise...I think...reduced. I noticed the S.P. dropped down a good bit to about .50. So maybe it is a filter issue. I will get a 1" filter and try that to see what happens.

I looked into the Advanced Menu. Here are some settings that I am not sure are the better settings:
Furnace Airflow - Comfort, Efficiency (It is set on Comfort )
Heat Pump Airflow for Cooling and for Heating - Quiet, Eff 325, EFF 350, Comfort, Maximum (It is set on Quiet)
I don't see a 'Minimum' setting that was mentioned.
Where is this 'Programable Fan Feature'? I can't find it.
Gary

[hvacrmedic]

Where is this 'Programmable Fan Feature'? I can't find it.
Gary

Go to SETUP-THERMOSTAT-PROGRAMMING-PROGRAMMABLE FAN. Set it to ON.

The MIN CFM setting is only available on modulating furnances.

[goddi]

Go to SETUP-THERMOSTAT-PROGRAMMING-PROGRAMMABLE FAN. Set it to ON.

The MIN CFM setting is only available on modulating furnances.

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Greetings,
Ok...I found the 'Programming' and changed it to OFF. What does this do and what does it effect??

I did a bit more testing of different filters:
My current filter is a Honeywell 4" that is about 2 months old. On HIGH, here are the results: CFM=1957; RPMs=1136; SP=.76.
If I replaced it with a used EZ filter: CFM=1957; RPMs=1010; SP=.50.
If I replaced it with a new Honeywell filter: CFM=1957; RPMs=689; SP=.50.
Even though the 'noise' does not dissapate, I can still detect it, the Honeywells are too restrictive (?). The EZ filters are more expensive but maybe, that is the way to go to at least address the high Static Pressure readings.(?)
It is difficult to compare the noise from each change of the filters because I have to turn off the unit, run downstairs, change the filter and run back upstairs and turn everything on. I'll try to do a video recording to get the sounds and edit it so I can more eazily hear the difference. But that will take me a few days to get around to it.
Gary

[beenthere]

Post a pic of the return duct at the furnace.

[hvacrmedic]

===========================
Greetings,
Ok...I found the 'Programming' and changed it to OFF. What does this do and what does it effect??

I was addressing the issue where the fan setting reverts to auto at the end of a call for heat. After reviewing your original post and the above post it would seem that the programmable fan feature was already set to ON, but AUTO was selected at least for the time periods where this event occurred. Go back and turn the programmable fan feature to ON, and then refer to your Homeowner's Manual for setting up programming of the fan speed. You can select AUTO, LOW, MED, or HIGH and you can set different values for various time periods. Select ALL DAYS to set the same speed for all time periods.

If the noise level drops with the less restrictive filter, but cfm remained unchanged, then the noise isn't due to air velocity, since air velocity didn't change. What did change was the rpm of the blower, and the static pressure between the filter and blower. The sound has to be due to leakage in the return somewhere, or the blower itself, either the motor or the blower wheel. HTH. FWIW 5 ton blowers are noisy on high speed, there's nothing that can be done to completely silence them other than moving the unit out of the house. A humming noise isn't normal though. Tape the edges of the blower panel with non-mastic type aluminum tape, the thin stuff, and see if that helps.

[goddi]

I was addressing the issue where the fan setting reverts to auto at the end of a call for heat. After reviewing your original post and the above post it would seem that the programmable fan feature was already set to ON, but AUTO was selected at least for the time periods where this event occurred. Go back and turn the programmable fan feature to ON, and then refer to your Homeowner's Manual for setting up programming of the fan speed. You can select AUTO, LOW, MED, or HIGH and you can set different values for various time periods. Select ALL DAYS to set the same speed for all time periods.
I went back to look at the 'Programming' menu. It has 'Programming- On/Off'; 'Periods per Day- 4/2'; and, 'Programable Fan-On/Off'. Both Progamming and Programable Fan were 'ON' and the 'Periods' was set to '4'. There are no other choices for AUTO, LOW, MED, OR HIGH. I misplaced my owners manual today, but I am sure there are no instructions in that little booklet pertaining to Progamming the Fan for various time periods. I'll keep looking.

If the noise level drops with the less restrictive filter, but cfm remained unchanged, then the noise isn't due to air velocity, since air velocity didn't change. What did change was the rpm of the blower, and the static pressure between the filter and blower. The sound has to be due to leakage in the return somewhere, or the blower itself, either the motor or the blower wheel. HTH. FWIW 5 ton blowers are noisy on high speed, there's nothing that can be done to completely silence them other than moving the unit out of the house. A humming noise isn't normal though. Tape the edges of the blower panel with non-mastic type aluminum tape, the thin stuff, and see if that helps.

I've got to go out for a while. Let me digest what you said above. But the noise seems to dissapear only when I remove the filters entirely.
Thanks... Gary


Added later...JUst found my owners manual. Yes, I see the Programming feature for the fan. But I have to go out for the day. Let me deal with this later.
Thanks... Gary

[goddi]

Post a pic of the return duct at the furnace.

Here's a picture of the Return Duct:

[beenthere]

While it looks like they vaned the ell. The actual set up at the furnace is probably giving you most of your high static. Thats a poor set up at the furnace.

[goddi]

While it looks like they vaned the ell. The actual set up at the furnace is probably giving you most of your high static. Thats a poor set up at the furnace.

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Greetings,
Not sure what you mean by ' they vaned the ell'. Is there anything that can be done to improve the existing setup? One suggestion one of their tech guys said was perhaps putting an additional return in the basement. I did not like that because it would be drawing in unconditioned air from the unfinished basement.
Gary

[RyanHughes]

I wouldn't add a return to the unfinished (and likely unconditioned) basement. It would be close to the unit (more pressure), and without the unit would draw lots of air and make the basement negative which you don't want. You have plenty of space to play with on the supply plenum, as it appears. Could likely raise the furnace and improve the return transition to the unit. Does return go into the side and bottom of the furnace, or just the bottom? You can pull the filter out and confirm if necessary.

Your static is high, but not extremely high compared to most systems. 2000 cfm is a lot of air, and unlike conventional systems, with a variable speed blower your system will provide 2000 cfm at .7" ESP. On most residential air distribution systems, .7" ESP is not all that irregular on larger systems with a partially dirty filter. The high static is the reason for the noise, as others have said. You have greater noise from the fan itself, as well as the noise of air traveling at higher velocities within the duct and through your grilles and registers. Things can (and should) be done to lower static for comfort/noise and efficiency reasons. A better transition will help. If the return is only coming in the bottom of the furnace (which I doubt), then your return is restricted. How many return grilles do you currently have and what size are they? Fed by what size ducts?

PS- What is your static in cooling mode? I'm guessing a reasonable amount less. In comfort mode, a 5 ton Infinity air conditioner on high stage will be at 1750 cfm max. Is the system only louder while heating?