Installing and Testing the RV AC Silencer


Anyone who’s checked out our blog for longer than twelve minutes knows that I’m not shy about messing around with our RV’s air conditioner.  In Lance, I think we went through four different air conditioners(!) in search of the quietest cool possible.  I’ve also been known to bust open sealed control boxes in our air conditioners to tinker with the controls to make them colder.  So, it should come as no surprise to anyone that this simple install to make the air conditioner quieter was a sure thing once I learned about it.  Behold!

 

 

The concept behind the RV AC Silencer is simple, and I understood immediately how it should help.  That’s why I got it and started on the install so quickly.  In the way of full disclosure, I actually purchased this silencer within minutes of learning about it.  The folks at Wacko Products learned about it and have since refunded our money before even seeing this video.  But honestly, now that I’m done… we’d buy one again.

First off – this is ONLY for ducted air conditioners, so it wouldn’t have helped us in Lance.  But it’s perfect for Number One, since we already have the ducted air.  The second thing to take note of is that there are different models of the RV AC silencer depending on which brand of air conditioner you have.  We have the GE, so we made sure to get the appropriate model.

At the heart of things, the RV AC Silencer is a baffle – meaning it routes the air intake not straight up into the unit, but rather has it jog sideways in an expanded intake box.  Not having a straight open pathway into the innards of the air conditioner helps a LOT with the sound.  That intake box also has some sound absorbing material in it to quiet things down further.

There’s also some increased efficiency that’s possible with the RV AC Silencer.  The kit comes with an electrostatic air filter element to replace the see-through foam filter that ships with.  You can also wash the electrostatic element without fear of it disintegrating.  I like electrostatic filters: I have one on my air cleaner in the shop.

And finally the last-last thing the RV AC silencer does is that it instructs you to seal up the direct discharge air conditioner output.  Now granted, this means you won’t have that option available if you wanted to use that vent location.  But since we like the ducted AC vents in our EKKO, we never planned on using that vent location anyways.  (And to be completely fair, you could seal up this opening on your air conditioner without buying the kit… all you’d need would be the foil tape.  But it’s nice that the kit reminds you to complete the job.)

So How Did It Work?

In my brief testing, the RV AC Silencer provided us with a dB reduction of about 2-3 db.  That’s doesn’t sound huge, but remember the dB scale is logarithmic, so it’s more impactful than it sounds.  But more significant than that was that both my lovely camera-gal Stef and myself felt like it was much less acoustically annoying with the RV AC silencer installed.  I suppose this has to do with the frequencies that are attenuated.  Imagine if you were trying to have a conversation, and I was standing next to you making a half-hissing, half-gargling sound.  It would be difficult to carry on that conversation!  Now imagine if I shut up.  Much easier to talk.  That’s the effect you get with the RV AC silencer installed.

And speaking of shutting up, that’s what I’ll do now.  As for us, the RV AC Silencer is staying.  As for you, watch the video and judge for yourself!

Cheers!

 



James is a former rocket scientist, a USA Cycling coach, and lifelong fitness buff. When he's not driving the RV, or modifying the RV (or - that one time - doing both at once), you can find him racing bicycles, or building furniture, or making music. In his spare time, he works for a large IT company.


    24 thoughts on “Installing and Testing the RV AC Silencer

    1. Fred Johlin

      Why not see if just taping over the secondary air output and upgrading the air filter might do the same thing? The cost would be less and no extra drilling would be needed.

      Fred

      Reply
    2. Adam J

      I’m sweating just watching this video… I don’t know how you guys function in 100+ weather. But I appreciate it!

      Reply
    3. Martine

      The manufacturer makes the claim that this device will reduce AC sound by 8-10 decibels. In reality, it reduced it by 2 decibels on High mode. Probably less on low mode. The price tag is $200. You lose your low profile on ceiling and can bump your head on the sharp corners. I don’t think that the price tag and labor justify 2 decibel reduction in sound. Besides, I like the loud whirring sound if I sleep on the roadside, or rest area, It drowns out other annoying sounds from the road and lets me sleep peacefully.

      This was a great demo, however, and well documented. Thank you!

      Reply
      1. James - Post author

        Well, the corners aren’t sharp and I haven’t yet hit my head. (I have hit it on the smoke detector though…)

        If you don’t think it’s right for you, that’s entirely your call. We’re keeping ours though!

        Reply
    4. Shaun Simpkins

      FWIW, although the ear responds to sound amplitude logarithmically, it doesn’t respond simply to amplitude. So researchers have determined that about 10dB in sound amplitude (a factor of 10) is perceived as a doubling in volume.

      Now you know why it’s so easy to damage your hearing at rock concerts and sports events. (“Naah, not much at all. Turn it up more!”)

      It’s also the reason why I don’t get all hot and bothered by a 2-3 dBA difference in amplitude…it’s perceptible, but not that much. It IS double the sound power, though, so that’s something from a hearing preservation perspective.

      Most ductless RV air conditioners are within about 6 dBA of each other. The Mach 10 NDQ is about 10dBA quieter as compared to the old Mach 10, but the Houghton 3400 clocks in at 15-20 dBA quieter, which is something to make you stand up and take notice. None are as quiet or as efficient as a mini-split (which is what a ducted RV A/C is, basically).

      I agree that the damping material in the Quieter is probably changing the frequency balance of the noise and that makes the perceived noise levels lower than objective measurement would imply. It would be great if RV A/C manufacturers used the Sone instead of the dBA. A Sone is a dB adjusted for human perception. Bathroom fan manufacturers use it to determine the annoyance factor of their products.

      Reply
    5. John Hawk

      I’ve frequently wondered why RV manufacturers put the A/C units and furnaces nearest to where we lay our heads at night. Most of us want as much quiet as we can get when we sleep and expect some noise when we are awake. We’re RV’ing to find peace and quiet and are paying higher and higher prices to do so. You would think the manufacturers would put a little more R&D into this field.

      At home I have a mini-split heat pump with an efficiency/SEER rating of 26 and both the outside and inside units are quieter. So it’s not impossible to make quieter units. Also there is a “whisper” setting on the inside fan – something I haven’t seen on my RV’s.

      Reply
      1. James - Post author

        Well, one *benefit* to having the unit by the beds is that the cooling performance will be best there. If the AC was up front, the air delivered to the back (ducted or not) would be the weakest, warmest left-over air. Stef and I really hate sweating while we sleep, so that much at least, we appreciate.

        I have a mini-split system in my shop, and agree that it’s quieter than any RV air conditioner ever. I’d be interested in seeing something like that in an RV. Of course, that system is also 240 volts and considerably larger than our RV AC as well…

        Reply
    6. Toby Carlson

      My only question is what about air flow??

      I mean as a past HVAC technician the sound is one thing but did it drop air flow so it also will limit or reduce the cooling effects of the unit??

      Thanks

      Reply
      1. James - Post author

        Not as far as we can tell. Still works fine.
        The commenter just below has been using one for a year with no ill effects.

        Reply
    7. Michael Butts

      I put one one (along with relocation the thermister see Thorforums.com and search for Try this first before you buy 2nd AC unit or bring your unit in for AC service) last summer. Although we’re not quite as hot in Michigan as Arizona, we typically are in the 70-80% humidity level most of the summer.

      1. I haven’t have any freeze-ups
      2. It makes the RV 11.3X more comfortable to use. No yelling over the din of the A/C, TV can be used without turning up to ear bleed level, and generally, it’s just a LOT nicer without all that noise.

      Reply
      1. James - Post author

        YES!!! Thank you!
        Since we just installed, obviously we don’t have any long term results to report. Thanks for filling in that gap for us!
        Glad to see you’ve been using this for a year with no ill effects and all the benefits.

        Reply
    8. Tsippi

      This is a great video, thank you. I’m pretty sure the engineers who designed my rig assumed people would run their A/C with the louvers open during very hot conditions. I say this because there are only three vents in the living room/kitchen/shower area compared to two over the loft bed and one in the lav. Before investing in this (admittedly great seeming) equipment, I think I’ll run an experiment and tape over the air outflow in the main unit. If I’m happy with the results in terms of cooling power, I’ll shoot for the whole set up.

      Reply
    9. Robert Garbe

      Let us know if the condenser freezes up since all that STUFF, tape and filters and air direction changes will reduce the air flow somewhat. In the east, it will be a problem, most likely.

      To really determine precisely, you need a board certified Industrial Hygienist and a tripod mounted type 1 octave band analyzer. Oh wait, I am one. Give me a jingle and we can set something up..

      Reply
      1. James - Post author

        I look at AC freeze-ups sort of like Alien Abductions: If they do actually happen, they’re exceedingly rare; and every time I hear someone say they’ve had one, I find myself feeling they’re not quite… right.
        Seriously though, nowadays, the air conditioners have freeze sensor probes on them (our Colemans did, and I haven’t taken apart the GE yet, but I bet it does). If it got close to freezing up, it would kick into a defrost cycle.
        And besides – the tape only more completely sealed off a vent that we kept closed all the time anyway. For that to be a problem, they would have designed it to leak cold air into the warm air intake on purpose, and I highly doubt that’s the case.

        Frequency analysis of the AC would be interesting, but probably deeper into the subject than most people want to get. A simple “sounds quieter” is likely enough detail for most.

        Reply
    10. Smiley El Abd

      Here is what happened, you closed off a supply that would have short cycled the unit, You installed a return air plenum for the return air with sound attenuation in that plenum plus forced the return air to make a few turns to again deaden air flow. What I think you may have missed is the added static on the supply side by closing off that discharge by forcing more airflow throu the ductwork PLUS the added return air static by having that upsized filter and plenum box. So you could of had lower noise by virtue of having less air flow out of the GE unit. Those RV A/C unit fans are not designed to handle much external static pressure. So unless you measured air flow out of all your open registers and surface area to confirm air volume you may have lowered noise by reducing air flow. Hey sorry that is what I did for a living with Mitsubishi HVAC.

      Reply
      1. James - Post author

        Or… everything is fine, the air conditioner is quieter, we’re happy, and there are no ill effects.
        Interesting points though.
        As far as closing off the leakage path for short-cycling, you’d have a hard time convincing me that was a mistake regardless of any back pressure created.
        And though I haven’t tested the airflow out of the ducts, it seems the same to us – at least in terms of overall performance.
        We shot the video two weeks ago, and we’ve been running it that way ever since. No noticeable performance impacts that we can tell.
        Perhaps the airflow was reduced in some small way, but we can’t detect it.

        Reply
    11. Rob

      I was wondering how much this product cost. Although there was a slight decrease in sound of a couple of decibels, is that significant? I also wonder what kind of reduction you would get at a lower setting.
      Another thing that I found somewhat concerning had to do with the heat in the van. Did you have doors and/or windows open? You were at 90 and it seemed to get hot again (100 degrees) very quickly. Obviously there was editing, but I would think the insulation should have kept at least some cooling effect for an appreciable amount of time.
      Maybe some investigation on insulation on that Ekko… if it is anything like a Travato, it is lacking. Is there a way to add insulation?

      Reply
      1. James - Post author

        I just bought the unit you see off the website I linked above. People will find this post years from now, so for current pricing, just follow the link.

        When it’s 105 inside the RV, my interest in trying the air conditioning on a lower setting is pretty much nil. lol.
        We never got it all the way down to 90. We just ran it for a few minutes and got it down to 98 or 99, and then got back to work. It was about 114 that day, and we went outside after work to film this starting at about 5PM, so the RV had been marinating all day in the heat, and we went out at the hottest part of the day. Probably not the smartest time to do it, but it’s the time I had available.
        I’m not yet looking for ways to add insulation to the EKKO. About the only place one could would be in the front cap area anyways. And maybe some inside the Transit parts like the doors or the firewall or the floor.

        Reply
    12. Adam Shinbrot

      IIRC, 6db is a SPL (sound pressure level) half as strong and hence half as loud. Logarithmic doncha know.

      Just sign me an old worn out engineer.

      Reply
    13. Don Wilson

      So this air silencer will next on our list of updates for the Ekko. Thanks James and Stef. Keep them coming.

      Reply
    14. James McCrea

      Great and extremely helpful video as always. I will wait to order until I know exactly what AC my EKKO is delivered with.

      Reply

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