Heating, Air Conditioning, Fridge, HVAC/Central AC Noise



I had a new 4-ton Carrier central AC unit installed in my home about 2 months ago.  (It replaced a 15-year-old builder-grade Comfortmaker)   The installation included replacement of the copper pipes going from the AC unit to my furnace. The new unit is installed outside on a concrete pad.

The problem is that the new unit has been much noisier than the old one since the day it was installed.  But if I go outside and stand next to it, it sounds no louder than the old one.  And it actually sounds like the noise is coming from inside the house as if vibration is resonating through the AC lines going to my furnace.  

We have had the installers back twice to address it.  The first time, they took the unit off of the brackets mounted to the side of the house and placed it on the concrete pad.  No improvement in the noise.  The second time, they installed a compressor blanket.  Still, no improvement. And they gave us the standard line..."some units are just louder than others."  

But I can't help thinking it has something to do with the way the lines were installed since they seem to be the source of the noise and neither of these "fixes" to the unit have had any impact.  Could this be the case?

The lines run perpendicular to and below the floor joists on the unfinished side of the basement, so I have complete access to them.  Is there something that can be done to either secure them better or insulate them better to alleviate the noise?


 No  do nothing with the pipes or anything else.  My God 2 months old??????  Carrier, well actually Bryant , which is carrier as is day & night and Payne.  
Back to you....Get on the phone and ask to talk to the owner of the company, no one else very polite like.  I just threw that in because it sounds like he gets these calls once in a while ( 2 months and 2 visits after the install?? )
 You will be happy to see how he will be more than happy to either get his top tech or himself out ASAP.  You have to honest to yourself as to the sales arrangement, if either of you ever talked about noise or......That said then it is not "special" circumstances, which is still an issue to be solved, but not one where they promised and it is worse.
 Now the part I cannot help with, is if you again bought a contractor model ( which is not cheap today) they do not cost as much because that is one of the differences in the models along with the SEER and HSPF.  If you have one that is a basic cabinet ( which might be )judging from the compressor blanket.  The positive of the cheaper ones are the air flow across the coil is better and they don't clog as much.
 Our moto is whatever it takes and that we live by.  And just know if it is not the line set part of the installation and just the unit itself, if there is a problem from day one with it and a couple of repairs do not cure it Carrier is the ONLY company that has a policy to just put a new one in.
 I will say if the copper is strapped tight to the rafters it could resonate and be very loud.  If you do not get satisfied write back.

[an error occurred while processing this directive]---------- FOLLOW-UP ----------

QUESTION: I spoke with the VP of the company after the first service call and he sent a specific guy out.  I assumed this was his top tech and he was the the one that installed the compressor blanket.  

As for the original sales arrangement, we didn't specifically note a "noise level" that had to be achieved.  I guess I didn't think it was necessary since the old one ran quietly for 15 years and was an inferior brand.  I would assume a proper installation would produce the same, right?   I mean, when I buy new tires for my car, I don't specifically tell them to inflate them, it's just part of the mounting.  I guess I'll try them for a third time.

But could you please provide a description of how the lines should be run so I can look to see if they took a shortcut or maybe positioned them in a way that would cause all if this noise?


Mark, they have smart phones there?   503-577-1128, snap a couple pics and text them, would really be the easiest way and fastest.  If not we can get it in a couple extra e-mails, I would like to see everything inside and the penetration point.
 Also, was the old one on that stand?

Heating, Air Conditioning, Fridge, HVAC

All Answers

Answers by Expert:

Ask Experts


john t. borgman


I am in Portland Oregon at Ben's heating 503-233-1779. I work days, so I can only answer early in the day or later in the evening. I only answer public questions for residential equipment. I am very well versed in gas, electric and heat pumps and will only answer residential applications. I have been known the past decade or so, by my employers as the guy you send when no one can figure it out. Trouble shooting is my special. I understand the physics behind air flow, refrigerants and electricity. I understand programmable t-stats, zone controls, economizers, fossil fuel kits and the engineering thought process in the wiring and construction of residential equipment


I was lucky enough to start in this field almost 30 years ago as an installer, for a company that installed the best duct systems I have ever seen, even to this day. The best ,as far as understanding the way air really flows through a duct system, from the return air to the very last supply register . They also had great pride and the duct work was put in, not only to last 50 years, but to look exceptional. Then as I started doing service work, I was again fortunate that I found a 3 year engineering class being put on be a man that was the educational director for the Entire united states for a society called " the Refrigeration Service Engineering Society " And for the next 3 years I schooled at night and practiced what I learned during the day, a great advantage over schooling and then trying to remember it years later.. Versed in duct design manual J heat gain/loss calculations.

Refrigeration Service Engineer's Society

I have 2 inventions that have gone through the process and been recorded at the National Institute of Standards and Technology from start to finish and thus been invited to national innovation workshops by the dept. of Commerce and the dept. of Energy. They are waste heat recovery devices that N.I.S.T approved as valid and am currently looking for marketing partners to get this product into the hands of consumers and make a BIG difference in Energy savings for every Household and Eatery and take a big bite in the the peak hours power consumption that face our Utilities companies.

factory training in Lennox ,Rheem, Ruud ,Trane, Tempstar ,Carrier, Day&Night, Payne, Bryant, Coleman, Intertherm, York, Goodman, Ultra boilers, Unico, Mitsubishi,Sanyo, Taylor, Nicewonger, Navien. Associates degree in Refrigeration Engineering. Certified with Energy Department, Check-me Program, P.T.C.S (performance tested comfort systems ), have N.A.T.E. certifications in gas, a/c & heat pump.

©2017 About.com. All rights reserved.

[an error occurred while processing this directive]