Air Conditioner

[marpel]

Sitting in the trailer (smallish with single AC unit), after a long days drive, with ac on, as it is a gazillion degrees outside, and am wondering - why are the RV ACs so darn loud? I was up on the roof the other day, cleaning it and from what I can see, the only moving part(s) is the fan, so what makes the noise. It is like sitting next to a jet engine.

And do they not make them so they can be run with a little less output? Ours is either on full blast or not at all (we can close one or all of the three outlets but that does not reduce the output of the unit, itself).

I have been in houses where they have a, somewhat, whisper quiet built-in (the smallish kind that sit in an exterior wall,), and our fridge keeps things cool without the jet engine, so why can’t they do the same for a rooftop?

Marv

[jjrbus]

RV industry has been ripping people off with poor products for years, at least they use to last!

First they chop a hole in the living area ceiling, then they put a motor, fan and compressor in the hole, directing the noise into the living area. Absolutely brilliant.

So now you have a vacuum cleaner running in the RV powered by a lawnmower under the unit!

For my Toyota I modified a window AC to fit on the roof. In my new to me Roadtrek I installed a LG9500 inverter AC, this AC is wonderful especially at night in sleep mode! The Roadtrek is designed for a window AC.

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/21943313/print/true.cfm

[jimh406]

There are noise reduction improvements for some RV air conditioners. They are brand and model specific.

On the other hand, some RVs aren't very well insulated, so hard to say what's causing the noise without specifics.

[liamricci]

What brand of air con do you have? We went with the Impecca and honestly i have no regrets about it. Unfortunately we lost all the books from the unit, but i was able to find Impecca ISAJ1821B1S manual online online without hustle. The most thing which i like about it - it is very and very quiet, practically i don't hear you, especially after our old unit, which was incredible loud all the time. So far, i didn't have to do any repairs, just cleaning it from time to time.

[marpel]

Thought I would post an update.

Decided to try the cheap, easy fix that I watched on a couple YT videos.

I built a diverter (upside down V) from some pieces of solid insulation, completely covered with silver foil tape. After sealing all possible air leaks in both bays (intake and cold air supply) with the same tape, I secured the diverter in the cold air bay. This effectively blocked the cold air straight dump, and diverted cold air to the two ceiling ducts. During measurements and design, I ensured optimum (from a layman's perspective) air flow to these ducts.

Once done, although we lost the straight dump, discovered the noise had dropped considerably and the cold air coming from the remote vents was noticeably greater. In fact, funny thing, by doing this I discovered we had a 4th a/c vent in the bathroom which, up until now, was so low/no volume, we had not even realized it was there. Go figure.

Total cost $10. Total time, less than a day.

[ktmrfs]

StirCrazy wrote:

jyenter wrote:
If you have a ducted system get one of these, https://wackoproducts.com/products/. Have one and it cuts the noise considerable.

I went and watched the video and ya it made a 2db difference which I would have thought it would do more, but what I didn't like was it disabled your cooling dump and you have to take the whole cover off with 4 screws to change / clean the filter. My AC is in the main area of the RV not the bedroom so when we are in there, I open that dump, so more cooling is going into the main area and keeping that space comfortable then when it is night, I close it so more goes to the bedrooms. if some one could make a system that keeps that feature available it would be great.

On our coleman Mach III it made a HUGE difference. Way more than 2db. Enough so that I often just run the AC on low fan to keep air circulating and noise level is very low. But then the MachIII is pretty noisy to start with.

I didn't do any before measurements, but today the AC is running on high and with my phone db meter standing directly under the AC unit it measures 56db at waist level, and sitting in the recliners it's 48db.

"normal" conversation is around 60db. Sitting in my living room now with no AC running, no tv etc my phone registers 40db and says "quiet living room"

I agree, the removal of the "air dump" feature is a downside, I wish there was a way to keep the air dump, my solution is that I have the aire port celing vents, Ijust close off the ones in the bedroom/bathroom if I want the living area cooled quickly and close off the living area vents if I want the bedroom/bath cooled way down.

[StirCrazy]

jyenter wrote:
If you have a ducted system get one of these, https://wackoproducts.com/products/. Have one and it cuts the noise considerable.

I went and watched the video and ya it made a 2db difference which I would have thought it would do more, but what I didn't like was it disabled your cooling dump and you have to take the whole cover off with 4 screws to change / clean the filter. My AC is in the main area of the RV not the bedroom so when we are in there, I open that dump, so more cooling is going into the main area and keeping that space comfortable then when it is night, I close it so more goes to the bedrooms. if some one could make a system that keeps that feature available it would be great.

[ktmrfs]

I have the wacko RV silencer, works great, and decided to also add the RV airflow system. The combo works great together, just got the rv airflow system installed. it's even quieter than before and cools better as well. usually if the temps are above 95F I better have the AC on early in the day and the temp will slowly rise above my 75F set point. 90 it would hold 75 if set there early in the morning, but would really struggle to drop the temps if I waited to turn on the AC.

yesterday afternoon the trailer was at 96F inside outside temp was 90F. Turned on the AC set the temp to 75F and waited to see what the system would do. In an hour it was down t0 85F inside and in two hours was at 75 so I set it to 68, in less than an hour it was cycling, outside temp by that time was 85 so it was cooling outside, but previously the AC would have had trouble dropping the temps and would would not have been able to get down to 75 let alone below 75

best of both worlds, quieter and quicker cooling.

[1320Fastback]

Our newer Atwood is so much quieter than the Dometic it replaced which wasnt that old either. I believe Atwood designed their units with airflow and noise in mind.

[marpel]

Thanks to everyone for the replies.

Interested in the Wackoproducts item so took a look at their site (thanks for the link).

Funny thing, they promise an 8-10 decibel reduction in noise (although initially, on the main page, they only promise a noise reduction, one has to hunt a bit for the 8-10), however, they also link an installation and review video in which the guy uses both a decibel meter and a db app on his cell phone. Both show a before/after comparison of about 2 decibel difference. 2 db is quite a bit different than 8-10.

As we have Dometic ducted a/c, will have to give this product further thought.

Marv

[sask66]

Replaced a Dometic 13500btu with a Truma Aventa 13500btu. It cools like you are in a meat locker and it is guiet. 3 fan speeds, and quiet inside and out. It runs off a remote. There are only a few places you can get them installed after market. Texas, Phoenix, Florida, and Elkhart Indiana.

[TurnThePage]

In my last RV the Coleman MachIII was pretty reasonable. In my new RV the Dometic is NOISY! They're both ducted. Coleman makes a quieter version now too.

Personally, by this time next year, I intend to have a nice quiet, uber-efficient mini-split installed. I'll leave the noise box on the roof just in case, but it'll get very little use I hope.

[Grit_dog]

Go sit in the garage, closet or attic with your head right next to your furnace/air handler fan, with the cover off. That will answer your question.

[ktmrfs]

jyenter wrote:
If you have a ducted system get one of these, https://wackoproducts.com/products/. Have one and it cuts the noise considerable.

yup one of the best upgrades we have done. Does eliminate the "air dump" feature(going from ducted to non ducted) but the noise reduction is dramatic and increases air flow as well.

[jyenter]

If you have a ducted system get one of these, https://wackoproducts.com/products/. Have one and it cuts the noise considerable.