Our RV Air Conditioner Upgrade: The Dometic Penguin II


Maybe you should watch the video first, and then I’ll explain:

 

Our Winnebago Travato, Lance, is just a little different from most others.  (OK, it’s a lot different.)  One of the changes that Winnebago made for us during the build was to mount our bed considerably higher than normal.  We have a full meter (40″) of clearance under the bed so that we can store our bicycles inside.

But the downside of this configuration is that our bed is alarmingly close to the air conditioner.  We sleep with our heads probably less than three feet from the indoor Air Distribution Box (ADB).  At that range, an air conditioner is REALLY LOUD.  As you can imagine, this presents some issues with sleeping.  This affects Stef more than it does me.

(Well technically, since Stef lets me know all about it, this indirectly affects me every bit as much as it does Stef.)

Another issue we had with the air conditioner was that we couldn’t adequately shut off the airflow towards our faces.  Sleeping three feet away from an air conditioner is bad enough.  But sleeping three feet away from an air conditioner that’s blowing directly up your nose is even worse.  And yes, I realize I could have used Great Stuff foam or duct tape to block the vent permanently, but I wanted something a little less… crude.

And even with all that, we might have been able to live with that air conditioner but for one final issue: it just didn’t seem to cool all that well.  In our older RV Das Bus, we had a Dometic Penguin II that would make the rig meat-locker cold.  We had never been able to achieve that in our Travato.  Between “unbearably loud”, “uncomfortable”, and “ineffective”, I might have been able to live with two of them.  But all three was just too much.

Thinking back on our previous experience, we got a Dometic Penguin II (a new model), and installed it in our RV.  You can see the whole swap-out in the video.  It was pretty comical at times, but we got it done.  But we did this purely on hope.  We had no way to test how quiet or cold the AC got until we got it installed!  I’m happy to report, all turned out well.

So, How Loud Is It?

Well, I can’t lie and tell you that it’s “pin-drop” quiet or anything.  We all know what RV air conditioners sound like.  But I can say with absolute confidence that the Dometic Penguin II runs quieter than our previous air conditioner.  Here’s a quick recap of the data I gathered in the video.  (The readings jumped around quite a bit, and changed as I would put my head or the camera up to see them, so please consider these approximate.)

Results in dB,  A-weightedOld RV Air ConditionerDometic Penguin II
Low Speed70.266
High Speed7169.5

Remember that decibels are on a logarithmic scale.  So a difference of 4 dB isn’t just a few percent.  It’s noticeable.  And while they’re not completely scientific, these off-the-cuff measurements reflect what my ears felt during the testing.  Namely, that the Dometic Penguin II is quieter than the air conditioner it replaced.  Much of this, I attribute to the Penguin II having a functioning low speed, something our old AC unit never could seem to get right.

How Cold Did It Get?

This is the result that blew me away.  Our Dometic Penguin II was cooling the air four degrees more than our previous air conditioner.  You can see the way I measure this in the video.  Basically, you let the AC unit run for a while to get up to speed (I ran them for 30 minutes), then you take the temperature of the inlet and outlet air and take the difference.  Here’s how that data stacked up:

Old Air Conditioner:

Inlet Air Temp:  68°  –  Outlet Air Temp:  48° =  20° difference.

Dometic Penguin II:

Inlet Air Temp: 67.2° –  Outlet Air Temp: 43.1 ° =  24.1° difference.

 

That the Dometic Penguin II cooled the air in our RV an additional 4 degrees is significant.  That’s 20% better performance.  It’s like the difference between an A+ and a B-.

How Much Energy Did It Use?

The Penguin II used 13 amps (AC) versus our old air conditioner which only used 12 amps (AC).

If the performance numbers surprised me, this one didn’t.  If you pull up the spec sheets on the Dometic Penguin II line, they’ll tell you that it uses slightly more energy than our old air conditioner.  The numbers we saw in our video bear this out.

And while the increased electrical load might mean I can’t run the new air conditioner quite as long as the old one on our battery bank, I look at it like this:  I could run our old air conditioner forever, and it still wouldn’t get the RV cool enough.  At least with the Penguin II, I have a better shot at being comfortable, even if it is for an 8% shorter duration.

Wrapping Up

One last little thing I like about the Penguin II is the number of options for airflow that its ADB provides.  There are FIVE vents on the Penguin II ADB, versus two (that didn’t really work) on our old AC unit.  Hopefully, this will help in keeping the wind off our faces when we sleep.

So there you go.  Besides just being better looking, the Dometic Penguin II was colder, quieter, and more adjustable than our previous AC unit.  We’re keeping it – and not just because it’s such a pain to hoist them up on to the roof!  Curious to hear your comments down below.

Full disclosure:  Dometic did provide us with the Penguin II we used in this video.  But I can’t make up results like this.  The replacement, the testing, and the results are all me.  I’m confident they could be replicated in any rig.  You can find out more about the Dometic Penguin II at this link.

 



James is a former rocket scientist, a USA Cycling certified 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.


    64 thoughts on “Our RV Air Conditioner Upgrade: The Dometic Penguin II

    1. Dan Goetzman

      Now that you have had the Penquin II for a while, how has it worked out?
      Seems like my Mach 10 unit is too loud inside and does not really get cold…

      You had a MACH 10 and initially reported good things about it… but longer term it turned out to be not so great a unit. Wondering how the Penquin has performed in the real world and if you still like it as much as when you installed it?

      Reply
      1. James - Post author

        Seems weird to be talking AC when it’s in the 40s outside, but yes, we do still prefer the Penguin II.
        It is still quieter than the Mach 10 was, and it cools better. REALLY better since I figured out how to hack the thermostat!
        Can’t beat the cooling performance. An AC would have to be considerably quieter still to get us to think about switching again.

        Reply
    2. Bill

      Did the penguin come as a complete kit? I looked at purchasing one and they have the bottom section of the page where “people who purchased this also bought”……

      Reply
    3. Tracy

      James,

      You are too smart for your own good! BUT…where are the safety glasses when using the drill above your face?

      Tracy

      Reply
    4. Han

      Hi James!

      Longtime fan, first time poster. Have you thought about installing a split AC unit? I haven’t found any specifically designed for RVs but I have seen a few DIYers install residential units with fairly positive results. The setup is probably not ideal for a Class B RV but something to consider if sound and efficiency are driving factors.

      Thanks and good luck!

      Reply
      1. James - Post author

        I have thought about it, but as you suggest, it wouldn’t be a straight forward swap like this one was.
        If I were building my own and could design it in from the beginning, it might be something to consider.
        Thanks for bringing up the question!

        Reply
    5. John

      I’d really like to see the efficiency and affordability of mini-split a/c or heat pumps available for class B. I include heat pump because it seems possible to provide all heating as well as cooling with such a solution in order to ditch LPG. From looking at the specs these small split systems would be much quieter and much more efficient for similar or less cost than what is currently offered for RVs. Some folks have had success using ordinary house units on larger RVs and camping trailers per YouTube videos. However, I haven’t been able to figure out a solution that would work, i.e.ensure reliable long term operation on class B, unless mounting external compressor and internal fan on the rear door is feasible. Food for thought in case the current solution still ends up being too noisy?

      Reply
      1. James - Post author

        Lots of focus and lots of options in RV air conditioning these days with more to come for sure. Who knows what our next rig might have!

        Reply
        1. Pete herrick

          Hi James,
          What model of ac did you replace with Penguin ? You should have had the Mach 8. The reason I’m asking is on the Facebook Travato section, some are stating that the Mach 8 is more quite than the Mach 10. The fix for Mach 8 noise was different fan blade and a different start relay which I believe were incorporated in the Mach 10. I had a 2012 plateau with 11,500 btu penguin that cooled really well. The pleasure actually had insulation in places. Thanks for you time
          Pete

        2. James - Post author

          We originally had a Mach 8. Then we got a Mach 10. The Mach 10 was quieter than the Mach 8, hands down.
          The Penguin II is quieter than both of them.

          Proper insulation really helps in any rig, so adding it wherever you can will only make things better for you.
          Cheers!

    6. Reid

      Having our Sprinter fitted with a Penguin II this fall. Might be an idiot question, but does the temp dial on the AC unit cause both the fan and compressor to cycle off and on, or does the fan keep running? We’re considering doing the touch thermostat to go with it for a bit more control, and maybe a less overall energy usage profile.

      Have really enjoyed your blog posts, especially with the data. Our build plan is quite similar to yours (induction, lithionics, penguin), and it’s been really great to see that someone else is doing it, as well!

      Reply
      1. James - Post author

        The dial on the AC only controls when the compressor cycles on and off. The fan speed is controlled by the other dial, and the fan is on constantly. I don’t know if you have the same situation with the wall thermostat, but I was running out of room to mount additional control panels, so I didn’t really look into it.
        Glad to know you’re following along with a similar build. We’re starting a trend!

        Reply
    7. william

      Can this air conditioner be run off shore power or solar while parked? And can I use solar or my house batteries to power the unit while driving down the freeway?

      Reply
    8. Jay Young

      Great video! Did you consider the Penguin model with the thermostat? The model number ends in 182. We would prefer to have the fan running only with the compressor. I am just starting my research so any other thoughts regarding the use of a thermostat would be helpful. Thanks.

      Reply
      1. James - Post author

        Didn’t really consider the model with the thermostat.
        If I were able to duct the AC, then a thermostat might make more sense. As it sits right now, the air distribution is “default”, which means mostly straight down. Putting a thermostat someplace not in the line of fire would probably yield unpredictable results based on what windows were open, etc.

        Reply
    9. Tom

      James, did you research the Atwood Air Command a/c as a possible replacement for the Dometic Penguin? I have been researching a quieter unit as a replacement for my Dometic and the Air Command is getting some good press on-line by those who have replaced their units with this brand. They claim their two motor design allows for lower amp draw and quieter operation. I believe this unit would require more work to swap out due to a different control/thermostat cable. Even if the roof top profile is not as low as the Penguin, the improved noise and cooling would be worth the change for me.

      Reply
      1. James - Post author

        I did look at the Air Command. But the wiring was a negative for me. Not that I couldn’t have done it if I really wanted to, but… bleh.
        They are supposed to be a bit quieter though.
        From what I could tell, the magic with that was in their ADB. It has guides/ramps/etc to move the air more smoothly.
        On the surface, it makes sense, but I would have to hear one in person before swapping out… again.

        Reply
      1. James - Post author

        I know refrigerants have changed several times since then due to environmental regulations. That may have something to do with it.
        (Heck – I remember being able to buy a can of Freon to refill my truck’s AC, back in the day.)

        Reply
    10. Alain

      With the lousy weather up in Quebec, I didn’t get a chance (or need) to use our new Penguin II, except for starting it to see if it worked. I was curious if you measured the startup curant? This is usually what limits A/C use on 15A circuits, The 13A running curant would in theory work on the 15A (or with a 2000W generator).

      Reply
      1. James - Post author

        The startup current is very transient. I’d need different and better equipment to measure it properly.
        Dometic lists the “Locked Rotor Amps” (LRA) for its units on their spec sheets. I’m thinking it was 63 or so?
        But that only lasts milliseconds.

        Reply
    11. Doug

      Great video. Thought for sure you would remind Stef that she is The FitRv girl while she was holding that rope. Probably a good decision to resist the temptation. 🙂

      Reply
      1. James - Post author

        Sometimes, she wants to be “the fit girl”, and sometimes she wants to be “the princess”. If I were a better husband, I’d be able to figure out when each was!

        Reply
    12. Mike

      Good video, and entertaining as well!

      How come Stef didn’t guide you back (while reversing Lance) with hand signals? 😉 Heh…

      Reply
    13. Richard S. Leitner

      James, awesome video and funny too. I think everyone has painted themselves into a corner from time to time. As far as the slightly higher amp draw, don’t forget it’s putting out 20% colder air so in should run less and overall use less power possibly, plus you’ll be more comfortable. Worth the price of admission for that alone. Safe travels.

      Reply
    14. Greg Moore

      Hi James,

      I had a 1994 Coleman 13,500 mach Air Conditioner. It wasn’t getting cold enough so I spent $800 on a new 15,000 Coleman Air Condtioner. Once again it was not getting cold enough. The lowest I could get both of these to go was 70 degrees and because the air was not dropping straight down below me where the dinning table was it was more like 75 or 80 degrees. I kept saying to myself this is nuts. Went on Youtube and was shown how to to change the thermostat reading! Now I wish I hadn’t had gotten the new one because it was still a great air condtioner that got thrown away. It just needed the adjustment. Check out how to do it:

      rv coleman thermostat how to make it cooler
      https://www.youtube.com/watch?v=jXmOLW0KZ-Y&t=249s

      Reply
      1. James - Post author

        Interesting.
        We can’t try that now because we no longer have our old AC. But even that wouldn’t have solved the “no low speed” noise issue.
        I also wonder if it would have helped us – because our compressor virtually never shut off! I don’t think it was a thermostat issue.
        But still… kinda cool adjustment.

        Reply
    15. Mark A.

      Great video, solid testing methods! What make & model inverter do you have that can power the Penguin II off your house battery bank?

      Reply
        1. Joe Ross

          Hello,
          Thank you for the information. I travel with my dog frequently and the standard dash ac just doesn’t do it. I am currently looking to set up a solar system to run an ac unit. Neither have been bought yet. What are you using to be able to power the Penguin II? Which is one of the ac units I have been looking at. I figured I should do both before I do my interior roof and walls.

    16. Interstate Blog

      A few weeks ago, I saw that Instagram pic of you carrying the new unit up what was presumably your driveway, and I got momentarily excited that you’d found an even-better solution than what you describe here. Momentarily excited until another Air Forums user pointed out to me that, no, it’s basically just the same-old-same-old. Although this new unit seems like it might be marginally better for you, it still falls way short of what I / we think Class B owners really need in terms of performance, especially where noise is concerned.

      Some upfitters are now experimenting with ducted undermount systems, but at least one of them (ARV, maybe?) is advising against it as initial results were not promising (I’m skipping details for brevity). The solution my husband and I devised is to simply not run our air while sleeping (and we live in Texas!).

      We don’t have a vaulted bed, so our numbers are slightly better – 70 dBA standing, 63 dBA sitting, and 60 dBA in the sleeping position. But 60 dBA is still really freakin’ loud. I’d rather sweat. And I do.

      Here’s an Imgur of our complete noise measurements. http://i.imgur.com/Hw6t4DK.jpg

      Reply
      1. James - Post author

        We’ll be visiting Advanced RV soon, so we will ask them about any AC experiments they’ve tried. But like you, I have heard the same unpromising things about undermount ducted systems.
        (Though in general, I like the idea of a ducted system.)

        Reply
        1. Interstate Blog

          I finally found that vid. So this is Neundorfer’s 1.5-minute take on undermount van a/c units – not positive due to the dirt issue:
          https://www.youtube.com/watch?v=eYBjy_58y0g

          Also, we do know that Roadtrek has started producing at least one of its models with undermount units. Some of them are situated where an Onan generator would typically be – in the tail, behind the rear axle. Which raises yet another issue – their effect on departure angle. Looking at this video below, they don’t even appear to have installed skid plates or wheels as protective measures. I’m not sure how well that configuration would stand up over time. This is a 4×4 van in the video. Presumably, the owner will drive it on some rougher roads.
          https://www.youtube.com/watch?v=wBF0xf6IxGk

      2. Aaron

        I wonder if ARV investigated compact ducted solutions like the Truma Saphir? (https://www.truma.com/int/en/air-conditioning/saphir-compact.php) It looks like you can even buy the Saphir aftermarket in Australia: https://www.youtube.com/watch?v=Tz_ZA3pQPL4

        Until Truma brings the Saphir to the states, a transformer would be required, but that should have been doable for ARV.

        James, if you and Stef could try one of these out while you’re in Germany, I’d be eternally grateful.

        Reply
    17. Ed Rudder

      Great piece and thank you for your efforts. In the future you should wear a pair of safety glasses. Just a thoughtful reminder. In my line of work, I have seen my share of eye injuries from looking up and material falling down. Again, wonderful and entertaining video.

      Reply
    18. Ray Brown

      I gave you a “thumbs-up” on the video because it was interesting, as most James’ fix-it videos are, but more so for the hilarity of the rope debacle! (Still laughing as I write!) Perhaps I’m too easy going, but I think I would have just waited until August to have the low switch on the old unit fixed, and are the results really that significant for the cost of a new unit? Plus, then there’s the heavier energy draw of the new unit. But then, we wouldn’t have this funny video if you thought the way I do…!

      Reply
    19. Gloria Levin

      Hi guys, this was VERY entertaining! And quite interesting for us, as we have considered a swap like this for my Dad’s travel trailer. The impromptu hoist is a GREAT idea! This makes the project seem far more doable as a DIY.

      Quick question; did you apply any kind of sealant or Dicor type stuff under the lip of the AC up on the roof?

      Thanks! Hope you’re having a great summer so far.

      Lori

      Reply
      1. James - Post author

        Hi Lori –
        Short answer, no. No sealant.
        These AC units all come with a compressible foam gasket already attached. When you tighten the bolts inside, that forms the seal, so no dicor is necessary.
        Go for it! It wasn’t all that difficult.

        Reply
      1. James - Post author

        The app is “Soundmeter” from Faber Acoustical. (It was kinda pricey for an app, but it was the most complete one I found.)
        It has A and C weighting. I was measuring on A.

        Reply
    20. Bob B

      Did you check the amp draw of both units on “Low”? Since this one seems to have a functional low speed – and that would probably be a speed you would use at night – I suspect it might draw less?

      Reply
      1. James - Post author

        Didn’t check the amp draw on “low”, since I was mainly interested in a worst case.
        Clearly, it’s too late to check the old unit now…

        Reply
        1. Roger

          I just did the test on the same model as your old unit (with all other electric draw off). On high, it waffled between 12 and 13 amps before settling on 13 and on low it settled immediately on 12, so not much difference.

        2. Bob B

          Well, it will still be interesting to hear how your overall energy usage works out with the new unit and the low speed. Great work as usual – both the install and the video explaining it all.

    21. Andy & Kim

      “Is this the best idea you could come up with?!?!?!?”
      ROTFL!!!!!

      Congratulations as you continue to transform Lance into the “Super B”!
      Andy & Kim

      Reply

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