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Old 05-10-2019, 02:47 PM   #1
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Default A/C Size for a B

I have a new Travato, with a 13.5K A/C unit.This A/C makes so much noise that it makes the van unlivable, unless you can turn it on after you go to sleep - neat trick huh. When I bought this I questioned the 13.5K size, my 2 other B's were Sprinter based, one had a 9K, the other had a 11K. I want to change the A/C for 2 reasons, the NOISE, and I donít feel that the compressor runs enough for dehumidification. What size is in your van, are you satisfied with the NOISE level, cooling & dehumidification ? Iím looking at the Penguin II as a replacement 11K BTU.
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Old 05-10-2019, 03:04 PM   #2
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I have a new Travato, with a 13.5K A/C unit.This A/C makes so much noise that it makes the van unlivable, unless you can turn it on after you go to sleep - neat trick huh. When I bought this I questioned the 13.5K size, my 2 other B's were Sprinter based, one had a 9K, the other had a 11K. I want to change the A/C for 2 reasons, the NOISE, and I don’t feel that the compressor runs enough for dehumidification. What size is in your van, are you satisfied with the NOISE level, cooling & dehumidification ? I’m looking at the Penguin II as a replacement 11K BTU.
Your complaint is a common one. Most RV roof air conditioners are practically unusable due to the noise. My understanding is that this is largely due to crude air-path and fan designs. Sadly, I don't think you will find an 11K unit much better. Ducted A/C setups are better, but are difficult to accomplish in a B-van.

You really have only a couple of alternatives:
1) Install a split system, with much of the mechanism outside the van. Some people have done this successfully, but others report that it is problematic, especially with under-vehicle installs.
2) Advanced RV imports a high-end rooftop replacement unit that by all accounts is much quieter than a typical RV A/C. They will install it in their Ohio factory, or ship one to you for a self-install. Pricy, though.
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Old 05-10-2019, 03:32 PM   #3
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avanti, the newer Coachmen 12 volt ac system is suppose to be quiet, FIT RV?



And this:

"This was pretty interesting. Coachmen is now installing 12-volt air conditioning units in their Class B motorhomes. The unit they are using is by ProAir, and it’s a roof mount unit, not an undermount. It’s got a claimed 20,000 BTU rating, which is considerably bigger than your typical RV air conditioner. Those of you who were at the Tampa RV show recently got the chance to hear one of these running in the Coachmen display, and it was pretty quiet.

But the big deal about the 12 volt air conditioning is that it will allow you to run the AC without needing a generator or inverter. For those of you who choose coaches without lithium battery systems, you would even be able to run this air conditioner while driving – again, without a generator. The thickness of wiring to the unit was not too bad (I asked), at only 2ga. In an informal test, I saw the unit pulling amps in the 50-60 range, which isn’t too bad at 12 volts (but granted, this wasn’t in summer). I suppose we’ll have to wait to see what people say about the performance, but I like that they’re trying new things like this at Coachmen."

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Old 05-10-2019, 04:32 PM   #4
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50-60 amps of 12v power for a 20K btu AC, so too good to be true. That is not even 750 watts. If that is real, it is very impressive.
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Old 05-10-2019, 04:40 PM   #5
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http://www.classbforum.com/forums/f5...html#post88095


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Old 05-10-2019, 06:29 PM   #6
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The forum link talks about variable speed DC compressor which are really DC converted to variable frequency drive like the Danfoss cooled frigs. Certainly makes sense.

Does anyone know what they are controlling the speed off of? I suppose it could be as simple as outside temp or maybe inside/outside differential or maybe based on evaporator temp to optimize cooling and dehumidification. It would be slick if it looked at the amount the indoor temp was off of thermostat setpoint and adjusted the speed to get the best recovery/efficiency balance to get to setpoint.
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Old 05-11-2019, 02:17 PM   #7
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50-60 amps of 12v power for a 20K btu AC, so too good to be true. That is not even 750 watts. If that is real, it is very impressive.
From the datasheet sheet photo I posted above you have to anticipate closer to 90 to 100 amps which is very similar to what I see with the 13.5K btu A/C on my motorhome running off the inverter. I think Avanti has sees about the same with with his setup.

I don't know if the 20K btu vs 13.5K btu matters of not in typical usage. It likely would help when in really hot/humid places.

As for quiet, as Avanti noted, a ducted installation makes a real difference. I would have though Advanced RV would have pursued this by now, maybe they have. A ducted installation seems to help performance also. I've had no trouble keeping the 34' motorhome comfortable throughout with the single rooftop A/C. A lot of rigs this size have two A/C's but I suspect part of that reason is that it costs less to install two rooftop units rather than a well designed ducted installation.
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Old 05-11-2019, 02:53 PM   #8
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From the datasheet sheet photo I posted above you have to anticipate closer to 90 to 100 amps which is very similar to what I see with the 13.5K btu A/C on my motorhome running off the inverter. I think Avanti has sees about the same with with his setup.

I don't know if the 20K btu vs 13.5K btu matters of not in typical usage. It likely would help when in really hot/humid places.

As for quiet, as Avanti noted, a ducted installation makes a real difference. I would have though Advanced RV would have pursued this by now, maybe they have. A ducted installation seems to help performance also. I've had no trouble keeping the 34' motorhome comfortable throughout with the single rooftop A/C. A lot of rigs this size have two A/C's but I suspect part of that reason is that it costs less to install two rooftop units rather than a well designed ducted installation.

We see similar amps from our 12K btu Coolcat non rooftop unit, although it would be nice to see in the spec sheet what they actually used for voltage (actual input voltage) for the testing. The current on the Coolcat goes up quite a bit as the voltage drops from full batteries to 50% full. If those amps they list are at actual 12.0v in, they might be considered better by some amount.
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Old 05-11-2019, 03:04 PM   #9
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As for quiet, as Avanti noted, a ducted installation makes a real difference. I would have though Advanced RV would have pursued this by now, maybe they have.
ARV has built at least one ducted system as part of their "super-tall" project (i.e., a Sprinter with the extra-high factory fiberglass cap). Looked really nice. I don't know if they every replicated the design. As I said, it is difficult to pull off in a B without the super-high roof.
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Old 05-11-2019, 03:35 PM   #10
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Quote:
Originally Posted by Toyman View Post
I have a new Travato, with a 13.5K A/C unit.This A/C makes so much noise that it makes the van unlivable, unless you can turn it on after you go to sleep - neat trick huh. When I bought this I questioned the 13.5K size, my 2 other B's were Sprinter based, one had a 9K, the other had a 11K. I want to change the A/C for 2 reasons, the NOISE, and I don’t feel that the compressor runs enough for dehumidification. What size is in your van, are you satisfied with the NOISE level, cooling & dehumidification ? I’m looking at the Penguin II as a replacement 11K BTU.
Does your current a/c have a true low or medium fan speed? I ask because my 6yr. old Coleman had two blower speeds, high and higher, which made it loud, regardess.

My new Coleman Mach 8 Plus (low profile) has a true medium speed along with high. While I'd say on high it is about the same noise level as the old one, it is significantly quieter on medium than the old unit (subjective, no decibel readings). So fan speed can make a huge difference.

Good luck.
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