Goodman forced air LOUD

RCgarden32

I had a Goodman forced air furnace and CAC installed in my Mothers 2nd floor condo. She couldnt hear well and never complained it was loud. Well I want to sell the place and this thing sounds like a blast furnace. It is located off the hallway and no way will i be able to sell the condo. When it starts up there is a loud wooshing sound which gets louder when the blower kicks in. I was told by her caregiver this is the way it has always sounded. I can not imagine Goodman puts out a product this loud even if it were located in a basement. I know its sight unseen but any advice would be appreciated. The guy who installed it says its working fine. NOT. If your a tech in central Jersey contact me please. Thanks for any advice and/or can it be adjusted. Lastly.. Who makes the quietest FHA unit and can it be used with the Goodman CAC unit thats 2 years old. Thanks

Ironman

It could be over-sized and/or the blower is moving too much air. Also, if the return air grille is close to the furnace and the duct not sound lined, that can create a lot of noise.

The problem is not the brand (though Goodmans like to move a lot of air), but a poor installation.

A good tech may be able to make some adjustments to quieten it down.

RCgarden32

Well there are 2 returns and 1 is in the hall ceiling about 8 feet from the unit and the other return is right there. 18 inches to the adjoining room. A small den. There is some sound deadening stuff there but I cant imagine that has anything to do with that crazy blowing wooshing sounds I hear. I know I sound like a nut with this discription but i am handy but not an HVAC guy. I good tech is a hard thing to find. But thank you
Are there any fan settings etc that I can adjust or try??

Ironman

A model number, size and some pics may help. How many square feet is the condo?

EBEBRATT-Ed

@RCgarden32

Check "find a contractor" on this site

pecmsg

Is the noise the sound of air moving, mechanical sound or both?

RCgarden32

The condo is at most 1200 square feet. I will measure when i get there today along with the model number and details of the unit. If I remember its a single stage 80% efficiency but the noise starts when it first fires up and then get louder when the blower kicks in. It appears the sound is coming from the force of the gas being fired. Its not a 1 time sound as it stays a constant wooshing sound until the blower kicks in and then gets louder. That sound may be air movement sound and I will have to pay more attention when I get there later. I have never heard a FHA system this loud. Will take some photos. Thank you

pecmsg

Can you post a pic of the ID Tag?

Being a Condo..........Units above, below Both sides or end unit?

RCgarden32

Free standing. 2nd floor with interior walk up stairs. No sides attached

Jamie Hall

With returns that short it's going to be noisy, and the noise is from the air blower.

retiredguy

I replaced my 20 year old American Standard 90+ forced air with a Goodman Model GMES920803B and boy what a difference in the noise level. I may be thrown out of my house by my wife if I can't reduce the noise level. The noise level could be reduced if the blower speed could be reduced to the next lower speed but the allowable temperature rise according to the factory is 35-65 degrees F. If the installing company had told me about the noise, I would have installed a different brand.

In mine, I reduced the gas pressure and the fan speed but the unit now it lights and vibrates slightly when the main burners fire. I would like to know just how much the temp rise can be elevated. The service guys say it can't be but I know they are "mouthing" the factory specs.

pecmsg

So you went from a 90+% unit to an 80+%?

80K is a lot of BTU's, how was the size determined?

You reduced gas pressure and fan speed, what were the combustion analyses readings when you were done?

Factory specs 35 - 65°F rise............That's It!

mattmia2

A furnace in a reverbarant closet on a wood floor with the required combustion air openings is going to transmit noise much better than a furnace on a concrete slab on earth in an open basement.

retiredguy

@pecmsg The old furnace was an 80,000 BTU 90%+ Amstan 2 stage and the new furnace is an 80,000 single stage 90% + Goodman. I heat 4000 sq ft living space. A 60 would have been the better choice.

@mattmia2 The furnace sits in the basement , on the concrete floor. The vibration lasts a couple seconds and is heard after the main flame lights. I am guessing that it is a flame pulse. I would be better at correcting the flame pulse of this furnace if it were a larger unit say 20,000,000 BTU boiler. And the 65 degree temp rise is max according to Goodman. Above 65 degrees there is an overheat sensor but I can find it's setting.

RCgarden32

Turns out the condo is more like 1400 square feet although the town has it listed at 1200. I will try to attach photos but I am not too techy. The unit is a Goodman model no. CAPF3030B6DB. Serial # if needed is 1807019134. Design press. 450. The return measures 12 x 14 at the unit. The hallway return measures 15 x 15 and is 10 feet away. The second return is smaller and located 2 feet away in the adjacent den. What I dont get is that the original unit wasnt loud and its replacement was tolerable. But this one is insane. I will try to attach photos. If I have to replace it who makes the quietest gas units. Hope it does come to that. Again, it is loud when it starts up (without the blower) and then sounds like a blast furnace once the blower kicks in.

Ironman

The pics are so small that I can't make out anything.

The "CAPF3036" is the model of The a/c evaporator coil, not the furnace. The furnace data tag is inside of the burner compartment.

RCgarden32

Ok. I will try again

ChrisJ

retiredguy said:

I replaced my 20 year old American Standard 90+ forced air with a Goodman Model GMES920803B and boy what a difference in the noise level. I may be thrown out of my house by my wife if I can't reduce the noise level. The noise level could be reduced if the blower speed could be reduced to the next lower speed but the allowable temperature rise according to the factory is 35-65 degrees F. If the installing company had told me about the noise, I would have installed a different brand.

In mine, I reduced the gas pressure and the fan speed but the unit now it lights and vibrates slightly when the main burners fire. I would like to know just how much the temp rise can be elevated. The service guys say it can't be but I know they are "mouthing" the factory specs.

Not trying to throw things off topic, but since this is considering a Goodman unit and the brand's rep regarding noise I wanted to comment. In 2017 I installed a Goodman 2 stage unit in my house ductwork and all and the first time I turned it on I was standing under the main return disappointed it didn't turn on, I couldn't imagine what I did wrong. I went down to get my meter to troubleshoot and when I came back up the stairs I realized the unit was actually running, I just couldn't hear it. In low stage it's nearly silent. In high stage it's still incredibly quiet.

Comparing a single stage unit to a 2 stage unit that was mostly in low stage is unfair period. It doesn't matter whos name is on it.

It's up to the installer to make proper ductwork to deal with sound issues.

bburd

Newer, higher efficiency furnaces move more air at a lower temperature rise than older ones did to supply the same amount of heat. A 100° F rise was typical in older furnaces; some of the newer ones top out at a 65° F rise.

More airflow means more noise, unless the ductwork and registers are altered to compensate. 

There are various ways to reduce the noise; I suggest you get a good HVAC technician to look at it. Two stage systems are really good for this, because they seldom need to run at high speed. However, they are more expensive.

bburd

Newer, higher efficiency furnaces move more air at a lower temperature rise than older ones did to supply the same amount of heat. A 100° F rise was typical in older furnaces; some of the newer ones top out at a 65° F rise.

More airflow means more noise unless the ductwork is altered to compensate, which can be difficult and expensive in an existing building.

There are various ways to reduce the noise; I suggest you get a good HVAC technician to look at it. Two stage systems are really good for this, because they seldom need to run at high speed. However, they are more expensive.

RCgarden32

I believe I have the model number. GMH80803BNBC. I will try to attach photos that appear normal size on my computer but we will see after I attach them. I have looked this furnace up on the net and I am pretty sure what you all will say. I watched it cycle when I took the front panel off and once it ignited it sounded like a blast furnace. Seemed excessive to me and then the blower kicked in and even more noise. Anyway, comments are appreciated. Direction to take even more. I am in Central Jersey and need this corrected. The returns join near the floor on the right. The opening to the furnace is 12 x 14 (maybe 12 x 15). The opening in the hall ceiling return 10 feet away is 15 x 15 and the other return is in the immediate adjacent room to the right of the furnace is about 12 x 14. Thank You Will get anything elese you may need including photos

Ironman

That furnace is twice the size that should be in there. And that would be on the coldest night of the year. When it's 35* outside, the heat loss is half of that.

No wonder it's so noisey.

ChrisJ

Ironman said:

That furnace is twice the size that should be in there. And that would be on the coldest night of the year. When it's 35* outside, the heat loss is half of that. No wonder it's so noisey.

They're in central NJ.  What about when it's 0 outside?  That's not terribly common but it does happen.   10-15 is common.

Ironman

ChrisJ said:

Ironman said:

That furnace is twice the size that should be in there. And that would be on the coldest night of the year. When it's 35* outside, the heat loss is half of that.

No wonder it's so noisey.

They're in central NJ.  What about when it's 0 outside?  That's not terribly common but it does happen.   10-15 is common.




If you'll read my comment more closely, you'll see that I was allowing for a design day of 0*.

pecmsg

ChrisJ said:

Ironman said:

That furnace is twice the size that should be in there. And that would be on the coldest night of the year. When it's 35* outside, the heat loss is half of that.

No wonder it's so noisey.

They're in central NJ.  What about when it's 0 outside?  That's not terribly common but it does happen.   10-15 is common.




Lowest I see for NJ is 6°F Most of the state is 10°F.
https://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/Design_Temperature_Limit_Reference_Guide.pdf?8eb9-ede8#:~:text=outdoor design temperature limit is 98 F and,is equal to or greater than 30 F.

That unit guestmating is 20 - 30% oversized for the area and ducts!

RCgarden32

Thats what i was thinking. So is there anything to do other than replace it? If I am replacing what size would be needed? (how many BTU) Should I upgrade to a better unit and or manufacturer? Surprisingly (to me) when it does get really cold (and it has this winter) it appears to blow warm and has trouble keeping up with the wind and cold. (Yes its a poorly insulated condo which I am addressing now.
Is there anywhere to find out how many decibels (approximate) these furnaces generate? I could not find any when I searched. Or is that something the manufacturers wont report. Thanks

RCgarden32

Ironman. Can you explain when its 35 outside the heat loss is half that. Obviously I am not a HVAC guy nor know the language. Also any thoughts on the above questions.. Thank You

ChrisJ

pecmsg said:

Ironman said:

That furnace is twice the size that should be in there. And that would be on the coldest night of the year. When it's 35* outside, the heat loss is half of that. No wonder it's so noisey.

They're in central NJ.  What about when it's 0 outside?  That's not terribly common but it does happen.   10-15 is common.

Lowest I see for NJ is 6°F Most of the state is 10°F. https://www.energystar.gov/ia/partners/bldrs_lenders_raters/downloads/Design_Temperature_Limit_Reference_Guide.pdf?8eb9-ede8#:~:text=outdoor design temperature limit is 98 F and,is equal to or greater than 30 F. That unit guestmating is 20 - 30% oversized for the area and ducts!

Those are design temperatures 
What I stated were actual temperatures.  Record low for my area in NJ is -19F and that's not wind chill.  I also stated 10-15 was common in central nj.  What part do you disagree with?

I asked where 35 degrees came from because it's certainly not a usable temperature for central nj.  35 is often the high during the winter.

Yes the unit in question is over sized.  I wasn't questioning that.

Ironman

If the outside design temp is 0*, then we have a 70* delta T (0* to 70*). However many btus are needed at that delta T, half that many would be needed at a 35* delta T (35* to 70*)

Example: if a structure needs 100K btus to heat it to 70* inside when it's 0* outside, then it would only need half that (50k btus) when it's 35* outside.

So unless a furnace is staged or modulates, it's always over-sized when it's above design temp outside. This why it's so foolish to over-size a furnace or boiler, yet the vast majority of HVAC guys will do it out fear it won't be big enough on the coldest day of the year.

Bigger is NOT better in Heating Land.

EBEBRATT-Ed

How about lining the return duct that may quiet it down? We used to have noise complaints in office building with a RTU on the roof and the installers didn't put in any return duct. Just sucked the air up through the curb.

We used to size the return drops at a friction of .05 drop down put a 90 on it and run 10-12 feet of duct and lined the duct.

That would do a pretty good job of killing the noise

They have rubber insulation now a lot better than the old dust catching stuff

DZoro

You could put a dozen different furnace brands in. You will find the exact same result you have now. When the furnace is properly sized to the building and the ductwork is properly sized to both. You will then find that the dozen previously loud furnaces are now performing at acceptable levels of noise. Personally I have found that Goodman when installed correctly is one of the quietest mfr's out on the market. Find someone who is willing to properly size the entire system. Not just someone to drop in a furnace. There as mentioned are ways to reduce some noise of the poor duct system, but it starts with proper furnace size.
D

Larry Weingarten

Hi, I'm probably being silly, but if two things were done to the furnace: putting in smaller orifices in the burners and selecting a slower speed with the blower motor, (if it has that capability) or putting in a lower hp motor... wouldn't that quiet it down?

Yours, Larry

HVACNUT

Larry Weingarten said:

Hi, I'm probably being silly, but if two things were done to the furnace: putting in smaller orifices in the burners and selecting a slower speed with the blower motor, (if it has that capability) or putting in a lower hp motor... wouldn't that quiet it down? Yours, Larry

Sure you probably could. But now you've altered things outside of manufacturers specs for that model, so if anything bad happens, you own it. No matter what. 

RCgarden32

So I guess I either have to live with it. NO way anyone would. Or replace it. Is there anyone on here in NJ that can correctly size and replace it. If I remember correctly when my mother moved in about 20 years ago she had to replace it and the contractor at that time said it was a "low boy". I have no idea what that was or still is and if that is what is needed. Finally where is a good place to search for a qualified tech to do the work as I dont live in the immediate area. Thanks for you time even if I dont understand all the HVAC dialog that has been conveyed.

ChrisJ

Fixing it properly will likely involve new ductwork, probably for the return.

5' of oversized flex on the return would make a huge difference if there's room to run it.

Ironman

Here are two good pros:
@EzzyT
@Danny Scully