Overhead Air Conditioning LOUD!

[73shark]

Originally Posted by AtlantaCpl

ersonally I would just as soon not have it. Just one more thing to remember to change oil for and we'll nearly always camp where there is power.

Brian

Well, either your A/C cools a lot better than mine or you haven't driven on a long trip w/ 7 or 8 people on board in 95+ heat. I can only get about a 17* degree drop across the evaporator even Dometic says I should get 21*. Also at 95*, it pulls about all of the amps the generator can put out.

It really needs the Sprinter engine driven rear A/C for cooling on the road.

[AtlantaCpl]

It's usually just the wife and I and we are in front with the cab air so you make a great point about use cases.

I think I can explain your 4 degree difference in temps. It is bound to be at least 4 degrees hotter than the ambient temperature on top of the sprinter with the heat radiating off the roof. I bet the intake is up on the hot roof which might explain the difference.

On reading the owners manuals I'm pretty good about reading them and did so in this case. But that was 2 years ago and obviously a lot of information to try and retain. I still have about 10 years to go until retirement to live life at a much slower and methodical pace!

Lastly, Airstream doesn't make the air conditioners but a strong suggestion from them to Dometic goes a bit farther than my lone feedback. Plus who knows if there isn't a much quieter model Dometic produces but Airstream doesn't like the increased price it has to pass on to the consumer.

Thanks everyone for the great discussion.

[73shark]

The Dometic doesn't bring outside air in, just recirculates. No connection to the outside air.

The measured drop was between the intake and output airflow. Basically the evaporator was only cooling the air 17* instead of the 21* Dometic told me. Removed both inside and outside covers to check for any blockage but found none.

Did find the junction box that AS uses to connect the A/C wiring to the RV wiring was not mounted but just hanging by the wiring. Fixed that. It did happen to be in the intake airflow so probably impeded it a little and probably contributed to the cacophony of noise inside the RV.

[Boxster1971]

Originally Posted by 73shark

The Dometic doesn't bring outside air in, just recirculates. No connection to the outside air.

The measured drop was between the intake and output airflow. Basically the evaporator was only cooling the air 17* instead of the 21* Dometic told me. Removed both inside and outside covers to check for any blockage but found none.

Did find the junction box that AS uses to connect the A/C wiring to the RV wiring was not mounted but just hanging by the wiring. Fixed that. It did happen to be in the intake airflow so probably impeded it a little and probably contributed to the cacophony of noise inside the RV.

Where is this junction box and can you get to it easily. I'd lie to check mine for similar problem.

Thanks,

[73shark]

You will have to remove the inside cover in order to see the junction box which is located at the forward end of the unit. You should be able to see it easily. There are some hidden screws involved in removing the cover.

[K3ors]

Soooo, has anyone actually been able to "fix" the noisy AC fan? My 2005 19' Bamie's fan sounds like it's ready fly apart. It is must defiantly not a normal noise.
We made our first camping trip this weekend and love Streaming!

[InterBlog]

Originally Posted by Protagonist

Scratching the itch of curiosity, which is louder… the air conditioner or the generator?

...

In the T1N Interstate, the answer is the air conditioner - no competition.

It is the reason why we will only use the Interstate in cool weather. We leave our a/c unit in the ceiling only for emergency use, like when I took our daughter on a university tour and we had 90+ degree weather in mid-October. I had to tell her that I need to turn this thing off for 10 minutes per hour. We could run it 50 minutes per hour but not 60 - I just couldn't take the intensity of noise, it was so exhausting. I needed periodic breaks from it, even if we were dying of the heat.

On another thread, someone talked about only being able to hear their cell phone in the wet bath, which had acquired the nickname of "the phone booth". But of course shutting oneself inside the wet bath to talk is perhaps a fate worse than death in high temps.

[Protagonist]

Originally Posted by Protagonist

Scratching the itch of curiosity, which is louder… the air conditioner or the generator?

Answering my own question—

I installed a decibel meter app for my Android phone to find out. The results…

Sitting on the driver's side side-facing seat and holding the phone almost directly under the A/C, the A/C fan running by itself measures 57dB. The A/C actually cooling measures 69dB. That's pretty loud. Normal conversation at arm's length averages about 60dB, and a multi-person meeting averages about 70dB. So the A/C is loud enough to make you raise your voice to hold a conversation if you're sitting under it.

Distance is a factor. Sitting in the front seats, the A/C actually cooling comes in at just 61dB, a difference of 8dB between the front and rear seats thanks to the inverse-square law.

Sitting in the same side-facing seat with the generator running but not the A/C, it's a whopping 82dB, or FOUR TIMES as loud. By CoE Safety Manual standards, that's loud enough to need hearing protection (>80dB), though it's just under the threshold by OSHA standards (>85dB).

Outside the van, holding the phone right next to the generator exhaust pipe, it's also 82dB. Which indicates to me that much of the generator noise inside the van comes from vibration transmitted through the van's frame, not from the exhaust.

[InterBlog]

This past weekend, my husband and I helped some extended family members move into their new ranch property. They custom-built their homestead and were careful about picking their a/c system to be as quiet as possible. It was so quiet that one had to be eyeballing the condenser to actually know whether it was running - it really wasn't audible above normal background noise. My reaction was, "You have GOT to be kidding me." It was so amazing that I hauled my husband away from one of his appliance installation jobs and out of the house so that he could witness it.

In stark contrast, own stick-house condensing unit, which is only about 6 years old? 74 dB about one foot from it, as measured using a professional sound meter just now.

I realize that that there is much more design flexibility available when building a ground-based unit - fewer size constraints, more room for coils, etc. But hopefully the technology on the RV units will move in an analogous direction and improve beyond what it is today. I would certainly buy a quieter roof unit if one were available.

[73shark]

Originally Posted by InterBlog

This past weekend, my husband and I helped some extended family members move into their new ranch property. They custom-built their homestead and were careful about picking their a/c system to be as quiet as possible. It was so quiet that one had to be eyeballing the condenser to actually know whether it was running - it really wasn't audible above normal background noise.

What brand was it? /\ /\ /\ When we turn our A/C on, I'll have to measure our York unit that's about five years old. I know it is very quiet w/ the air movement from the condenser fan being the most noise. That being said, it is a two stage unit and I don't know that I've ever been near it when it was running full blast.

For those of us that just use the AI for travel, the chassis based six ton rear A/C unit like the one on the Transit conversion that the local upfitter showed us is both the quiet way to go and it also actually cools the rear.

[m.hony]

We have a Lennox and it is very quiet as compared to the previous unit or the neighbor's unit.

[InterBlog]

Originally Posted by Protagonist

Answering my own question—

I installed a decibel meter app for my Android phone to find out. The results…... The A/C actually cooling measures 69dB. That's pretty loud. ...
Sitting in the same side-facing seat with the generator running but not the A/C, it's a whopping 82dB, or FOUR TIMES as loud. ....

What the hhhheck contraption did Airstream install in your rig?! Sitting inside, your generator is 82 dB? Seriously?! I can't even imagine that!

Here are our numbers, which I finally measured today. Standing, Sitting and Sleeping refer to spatial positions relative to the couch, which in our case is a jack-knife configuration in the rear - other floor plans might yield different results. By n/a I mean that there's no way I'd attempt to sleep with the a/c on anything but the "low" setting.

As I had noticed qualitatively, the a/c is significantly louder than the generator.

The meter I used here is a low-end professional device that I sometimes use for semi-quantitative work-related illustrations. City of Houston has no zoning but it has been known to enforce its noise ordinance. So sometimes I argue with my clients about what they should and should not build in new locations based on how loud I measure their existing operations to be.

[amirm]

Originally Posted by InterBlog

What the hhhheck contraption did Airstream install in your rig?! Sitting inside, your generator is 82 dB? Seriously?! I can't even imagine that!

SPL meters in phones are not calibrated, nor do they measure the same spectrum. So his numbers are not absolute and would not match another person's measurements with a different device/phone. But can be useful in relative way which I think that is how he intended them to be.

[InterBlog]

Just an observation in passing...

It's only ("only") 55 dB on the floor of my Interstate toward the cab. I know this because I spent quite some time on my hands and knees templating for a weatherproof overlay mat. We invested in a wonderful custom cab carpeting job and a few months ago, but it's getting soiled by muddy feet because there's no overlay yet. And there is none that can be bought off the shelf for the T1N Interstate so today was the day that the templating finally got done.

In contrast to the measurements in post #32 above, I could handle 55 dB (for comparison, my stick house is 41 dB with the central A/C running and the air whistling through the registers, but remember it's not a linear scale). Which means that if I were traveling alone and forced to sleep with the A/C running, I might be inclined to throw my 4-season Thermarest on the floor and sleep there instead of the bed. Cooler air settles, so it was actually quite nice down there, all things considered.

[InterBlog]

I'm just about wetting my pants with excitement... yesterday, the FitRV Instagrammed a pic of James and a delivery guy carrying a new-in-box air conditioning unit up their driveway, for their Travato. If anyone is capable of figuring out how to resolve this loudness thing, it would be James. I know I'm not the only one who is waiting for the installation and their verdict on what kind of improvement this achieves.

[FlyFishinRVr]

Originally Posted by InterBlog

yesterday, the FitRV Instagrammed a pic of James and a delivery guy carrying a new-in-box air conditioning unit up their driveway, for their Travato.

If I were a betting man, I'd put money on it also being a DC unit....

[UKDUDE]

Originally Posted by FlyFishinRVr

If I were a betting man, I'd put money on it also being a DC unit....

If you look at the box closely, it's a Dometic Penguin II. Doesn't look anything special to me, just low profile with a heat strip, and is 115V.
https://www.dometic.com/en-us/us/pro...uin-ii-_-20669

[FlyFishinRVr]

Originally Posted by UKDUDE

If you look at the box closely, it's a Dometic Penguin II. Doesn't look anything special to me, just low profile with a heat strip, and is 115V.

https://www.dometic.com/en-us/us/pro...uin-ii-_-20669

Well that's disappointing. Seems James was keen on moving away from relying on the grid so I guess I don't see the point.....

[Bgibbs]

Our FC has the "new" ducted air and if it's quieter that the older non-ducted I feel sorry for those without the new air. Ours is very loud. Not just fan noise, but sounds like it is vibrating against the roof. When the heat pump comes on, it adds a groaning sound. Both a/c's were replaced under warranty because they quit cooling and I swear that the replacement units are louder than the originals.

One positive is that Joan says she can't hear my "alledged" snoring with the units on.

[InterBlog]

Originally Posted by UKDUDE

If you look at the box closely, it's a Dometic Penguin II. Doesn't look anything special to me, just low profile with a heat strip, and is 115V....[/url]

Oh, you're right - I see the box now. His logic isn't yet apparent to me - yes he has been moving to off-grid capacity, so I assumed this would be a mod-in-kind. I guess his reasons will become apparent soon enough.