Discharge Mufflers- who has used them and what are your thoughts

[clydesdale]

I have a trane xl15i that makes a resonating sound that we hate. I have the original lineset in the wall, but have a neighbor who has a new exterior lineset and he also has a resonating sound in one room. We both have these problems on the second floor only. I thought I would buy a new lineset, but I am beginning to think that the resonance will still be there and that this maybe a problem with the xl15i and the length of lineset combo.
I am wondering if anyone has had luck with discharge mufflers. It was recommended to me to look into Refrigeration Research mufflers and I plan on calling them today. But, I wanted to get some feedback from the pros. What would it take to attach this to my system?
Also, I may have some trouble with my contractor. When I emailed him about this, I asked what his opinion was and sent him a link to the muffler and his exact response was "no opinion". He also said putting in a new lineset would be a "gamble" and I am not liking that. I don't see why it should be so hard to find why this thing resonates.

[skippedover]

Discharge mufflers have been relatively rare to non-existent on residential equipment but are now a required item on the Carrier Greenspeed and Bryant Extreme outdoor HP units. They require a minimum of 12-inches of straight pipe both before and after the muffler.

[clydesdale]

The discharge muffler on those units, is it something made by carrier for those units or are they adding an aftermarket, like Refrigeration Research? Do you know why they are required on those? Thanks.

[skippedover]

The muffler is supplied by Carrier/Bryant with the modulating outdoor units. There is a Carrier/Bryant part no. LM10KK003 listed in the install manual but we've not installed one of these units to date so I cannot speak from first hand experience. However, apparently the potential for line noises is significant or they wouldn't require the extra cost and time to install the product. This is just one example of how the Carrier/Bryant product line is supported. The leave non stone unturned before bringing a product to market. Lately I've answered a number of questions about a new User Interface forthcoming from Carrier/Bryant and WiFi capability. While I haven't heard anything concrete, what I do know is that it will be thoroughly tested before it's released if they do in fact have one in the making.

[clydesdale]

Knowing my neighbor, with a new exterior lineset, hears this noise on his second floor, I am beginning to feel this is a Trane flaw. I will call the discharge muffler company and get their thoughts.

[wahoo]

Have you contacted Trane's customer service department? If not, why not? Make sure you have all the model and serial numbers on both the inside and outside units along with installation date before you call them. Good luck!:.02:

[BaldLoonie]

A lot of units have a muffler in the discharge line from the factory.

Not unusual to have a scroll transmit some noise inside on the lineset in heat mode. A pain in the neck to deal with.

[Shophound]

If the lineset is in direct contact with structural members of your house, you can hear compressor pulsations/resonance, etc. Running an exterior lineset may not solve the problem if it also comes into direct contact with the house structure once it enters the building.

The key is to isolate the lineset from the structure by avoiding direct contact with structural components, particularly where it must pass through the building shell and continue its journey inside. This is seldom done, but I'd rather research a remedy from this angle vs. field modifying a factory condenser with a muffler.

[clydesdale]

I contacted Trane, right from the outset. But, they wanted me to work through the dealer. But now that he is un-interested in the discharge muffler and the lineset is a "gamble", I am beginning to get concerned that this is going to get ugly.

[skippedover]

If you've contacted Trane and they're not interested in helping, I'd suggest you may want to find a nice way to inform the installing company that you're not going away and need they need to find a solution. That may be via telephone, mail, e-mail, or a visit to their office. I would suggest that you be willing to work with them, understanding that it is in all likelihood a difficult fix. But also let them know that this is, according to Trane, their problem.

In order to bring a solution, you may need to consult with another company if the current one continues to be unresponsive. In that case, if you want to demand reimbursement when the problem is finally resolved, you'll need to provide some documentation that you've given the original installer an opportunity to fix the problem. That's usually a letter delivered by certified and regular mail (be sure to show the tracking number of the certified letter on both copies) stating that you're giving them 30-days to effect a satisfactory repair. Once the 30-days has expired, then you can hire whom you want to do the repair. None of this precludes our calling in another company to make suggestions before the 30-days expires and if you won't be seeking reimbursement for the repair, then there's not need to go through any of the legal steps.

I truly hope you can nicely work out a solution with the installing company. They may have no idea where to begin with such an issue but should be encouraged to contact Trane as their "assistant" to suggest solutions. Trane has a somewhat unique method of tech service. Normally there's a Field Service Rep who works directly for the distributor. He's the initial contact person for the dealer. When things get too complex for the FSR, he then has phone numbers he can use to get through to the factory. As you can see, there are multiple opportunities for potential pushback along the way. But I sincerely hope you can take the high road and engineer a workable solution for all.

[beenthere]

HVAC Mechanic, this is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise here. Please apply to the AOPC today, thank you.

You can find the rules for posting and qualifications here (http://hvac-talk.com/vbb/showthread.php?t=957002).


Further infractions may result in loss of posting privileges.

[clydesdale]

I am a patient man. I have and will continue to work politely with the contractor. But, I do not think we shoud "gamble" on any fix. From what I can see, the Trane xl15i has good reviews and the homeowner should not feel the desire to strap it to his truck and rip it out. I will call Trane and continue to be polite. But, we are close to the point where I need to get more firm and depending on the contractors reaction, our relationship may get a little bruised.

[clydesdale]

I'd love to hear what you have to say. I take help from all avenues. But my undestanding is that you have to register with the forum.

[beenthere]

HVAC Mechanic, this is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise here. Please apply to the AOPC today, thank you.

You can find the rules for posting and qualifications here (http://hvac-talk.com/vbb/showthread.php?t=957002).


Further infractions may result in loss of posting privileges.


This is a privately owned forum. Please read and follow our rules.

[clydesdale]

Refrigeration Research suggested that I contact Trane and thought that they would have a muffler for the machine. He says it is fairly common and that they should be able to provide some assistance.

[woody19]

Carrier also has a mass dampener that fits over the suction line inside the condensing unit that has solved many noise issues like you are experiencing. It isn't a guarantee but should help and is cheaper than running a new lineset. Also, Carrier recommends making an inverted trap just exterior to the cond. unit that rises up 12 inches and loops 6 inches and then back down.
The Carrier part number for the dampener is 328209-751.
Another possibility is system charge not being correct.
Good luck.

[clydesdale]

ok, thanks. They claim the charge is ok. He did come back and hook his gauges to it and was satisfied. The system seems to function fine. I just HATE the drone. I will call Trane tomorrow.

[woody19]

ok, thanks. They claim the charge is ok. He did come back and hook his gauges to it and was satisfied. The system seems to function fine. I just HATE the drone. I will call Trane tomorrow.

Any updates? We are curious if your problem has been solved.

[clydesdale]

Yes, I called Trane. I have a customer service reference or case number and Trane is going to contact my dealer. I told them I have no ill feelings toward the dealer and want to work with them through this. But, I have a neighbor with the same condenser with the same resonance and he has a new lineset. So, when my contractor says a new lineset will be a "gamble", I get nervous. So, I am asking Trane for help to guide us so that we don't "gamble" with my hard earned money.
They seemed receptive.

[clydesdale]

I wanted to update this thread too. Trane, after 5 calls and speaking with supervisors, provided zero help. They appear to have no influence.

[glennac]

Had the same problem with a Rheem 3 Ton HP. Cut down most of the noise with by clamping the liquid line to the suction line after leaving the condenser with a couple of U clamps for about 6" of length.

This transfers the high frequency vibrations to the suction line. The much bigger suction line absorbs most of the of the harmonics. This killed nearly all noise in the heating mode but before doing this it was loud. The noise was heard in the kitchen on the second floor directly above the line set running under the floor. Give it a try. Thank you, thank you very much