Dometic Penguin II NOT Performing...

[Michael_Wild]

I just bought a Dometic Penguin II air conditioner from Amazon and it is not performing as well as the original AC on my 1984 Airstream 310 MoHo.

I am very disappointed. I bought the new AC because I was expecting a more efficient and better performing unit than the 34 year old one.

Is this normal, or did I get a bad unit?

With an inside air temp of 34C/93F it was only pumping out 30C/86F air.

[AtomicNo13]

My penguin is pathetic as well.
The air box is terrible at distributing the air....
My 30 year old unit made my AS like a meat locker... This new one is crap.

[Belegedhel]

Huh?

[Michael_Wild]

Originally Posted by AtomicNo13

My penguin is pathetic as well.
The air box is terrible at distributing the air....
My 30 year old unit made my AS like a meat locker... This new one is crap.

Is it the difference between the older units that used freon and the newer ones that don't?

[Michael_Wild]

Originally Posted by Belegedhel

Huh?

Do you have any experience with these?

[Michael_Wild]

Is the Coleman Mach 8 any better?

[cowdiddly]

Actually, I think that is pretty good and normal. Your inside air is 93 and in one trip across the coils it is lowering the air temp 7 degrees. So the theory is when all the air inside the camper has been replaced with the now cooler 86 the next round trip displacement of all the air inside the camper would drop it down another 7 to a comfy 79. I think most auto AC only drops about 2-3 degrees each round trip displacement but the volume of air is small so it replaces the air with cooler fairly fast.

This is simplified of course and don't take into account skin heating, drafts, air mixing ect but given time that ought to be pretty good. But as another member stated you can never get the efficiency vs the older units with more efficient refrigerant of R22 vs the the new stuff which which has to run at higher pressures to even compete with the old freon.
Hi, my name is Mr. Armstrong. Miss me yet? Mine is 48 years old and still blowing ice cubes. Replace it? Not on your life until it absolutely croaks and I cant find a part anywhere.

[bobmiller1]

The Penguin is the best unit I have ever installed.....try their customer service for help.....maybe you missed something on the install, sounds to me like your compressor my not be running, based on your picture the left knob should be set to max, not AC FAN, Regards, Bob

[gr.austin]

Here is a rule of thumb: Find how much air the A/C is moving. A 13,500 BTU unit should be moving about 400-500 CFM. Look in the specifications. Now measure the temperature of the air going into the A/C. Getting as close to the Evap coil measure the air leaving the A/C. Subtract these two temps, Multiply by 1.08 and then by the CFM you looked up. This should be close to the rating of the unit: 13,500. So you see that 7 degrees is just not right.


Does the 7 degrees increase when you put the unit on low fan?


Are you making a lot of water? If you are then the drop in temp is reduced by the amount of water that is being made. If very little water you have a problem.



Your symptoms do suggest that the unit has lost charge or the expansion device is blocked or stuck.


I would also check if there is anything blocking the coils like stretch wrap or cardboard.



I would expect that 13,500 / 1.08 / 500 would give you at delta temp of 25 degrees.


The leaving air temp should be 65-70 degrees with 93 return air.


This problem certainly requires a call to Dometic to see how they are going to handle the warranty.


There are lots of potential issues and trouble shooting does require a trained service person. Fixing this is not for the DIY. This problem could KILL (no kidding) the untrained. Please call a professional to fix this under warranty and Dometic guide.


Happy streaming

[mikesSE]

My second Penquin 2 sucks.I bought it new last year and it failed and was replaced by Dometics as they knew it was faulty.The new replacement does not cool until it has run thirty minutes,then only marginal compared to the old Penquin 600.The load starting is terrrible and I can't run it on a 5000 Honda to start it.Dometics screwed the pooch on this one!

[bobmiller1]

Interesting .......

[jcanavera]

Is that AC/fan switch a fan speed switch? If so, on a cool down you should be set a max fan speed. Depending upon heat gain (say you are in full sun) this will provide the best initial performance of your system. Once cooled down you can change that fan speed to what works best for you. Just did a little checking and that switch gives you multiple speeds for cooling. So obviously to get max cooling you need that fan set to high.

I pulled this from an article on poor RV ac performance.

A. Temperature change.

In other words what the difference is between the temperature of the air going into the filter and the air coming out the discharge. The technical books say this difference should be a nominal 20° with the compressor running. I have seen it as high as 32° and as low as 16°. Some considerations for this temperature difference are:

• The two thermometers used to determine the temperature difference must be calibrated to each other.

• The books say the compressor should run for 30 minutes before the temperatures are taken.

• The temperature differential will be inversely proportional to the relative humidity. The condensation out of very humid air will build up on the evaporator just as the air filter contaminants mentioned earlier and act as an insulator.

So assuming your unit is new, I'm assuming that there is no packing materials that were forgotten that may be interrupting air flow. Secondly the amount of humidity in the air will absolutely affect the output air temperature. Until that moisture gets wrung out, a lot of the cooling will be spent on removing that moisture in the air. So let that unit run at high speed for at least 30 minutes to an hour and measure that temperature at the filter intake and the cooler air coming from the discharge. If you aren't getting at least 15 F+ difference between intake our outflow, you may have a problem. If you are then the only thing I could consider is the unit may not be able to overcome the heat gain. I had this issue with a 2001' 27' Safari in full sun hot weather. We dealt with that by adding a Zip Dee awning that spanned about 20' of the street side. That unit was 13,500 BTU's. When I ordered my 30' Classic I upgraded to a 15,000 BTU unit. (13.5 K was the standard at that time)

Jack

[Al and Missy]

If the gauge you showed is indicating humidity on the top and temperature on the bottom, at 33% humidity you should be getting better cooling. Heat gain into the trailer will determine the ultimate temperature but has no effect on the temperature drop across the unit. I'd say a call to Dometic is in order.


Al

[Al and Missy]

If the gauge you showed is indicating humidity on the top and temperature on the bottom, at 33% you should be getting full cooling from the unit. Also it seems that the trend is up, not down, as it should be if the unit is operating properly.


Heat gain into the trailer will determine the ultimate temperature and the time to get there, but does not affect the temperature drop across the unit. You should get a minimum of 15 degrees and hopefully more like 18-20. To be sure the measurement is accurate, one thermometer should be in the inlet air stream and one in the outlet, as close to the coils as possible.


I'd say a call to Dometic is in order.



Al

[superChop]

I agree that Penguin II are bad air conditioners! Three examples: 1. Brand new unit and the Fan needed to be tightened before first use. Required trip to Dometic authorized service center. 2. They are noisy. A fellow at an Airstream Rally with a vintage trailer informed me that he planned to upgrade his decades ol AC to get a quieter new Penguin II. When he listened to mine, he changed his mind. 3. I checked with another camper at a Rally if his Pengin II had difficulty pushing/routing air forward. He checked and said “Yes”. Only way we could make it to blow cold air forward was to close side, back and down vents = UNACCEPTABLE! 4. I contacted Dometic via email and their customer service engineer informed me these Penguin II’s are designed to require vent closure to move cool air forward. I was astonished and asked her why the back, side and front vent covers were so flimsy since I needed to open and close vents multiple times during the day. My vent covers have broken and we purchased multiple replacement vent covers. Next RV show when Dometic Representatives are attending, please let them know how displeased customers are with their cheap and poor design!

[gmillerok1]

Originally Posted by planBe

I just bought a Dometic Penguin II air conditioner from Amazon and it is not performing as well as the original AC on my 1984 Airstream 310 MoHo.

I am very disappointed. I bought the new AC because I was expecting a more efficient and better performing unit than the 34 year old one.

Is this normal, or did I get a bad unit?

With an inside air temp of 34C/93F it was only pumping out 30C/86F air.

What btu is your unit (11,000, 13,500, or 15,000)? I just replaced my older (circa 2011) Dometic Penguin for a 15,000btu Penguin II. The temperature difference was at least 20F delta from the ambient input to the cooled output. I'm guessing that if you have an 11,000btu unit or the 13,500 unit, the delta will be less as the only difference is the compressor's efficiency.

You may want to take the cover off, and inspect the area where the cold air comes out and make sure it is completely sealed to the area where it goes in. They may have accidentally cut the material or failed to seal it properly allowing warm air to enter the air-stream (literally ). This could account for the lack of cooling. In my unit, I took the thin cellophane type material off, and replaced it with some plastic insulation backed over with aluminum tape to completely seal and isolate the cooled air output from the intake.

GM