Pro Air 12 Volt A/C

[DUTCH in Atlanta]

Coachmen is now offering the Pro Air 20K BTU 12 Volt A/C on the 2019 Galleria instead of the Dometic Low Profile13,500 A/C, which is no longer offered. It's a very expensive option, but it's either that or no A/C.

Anyone have experience with this 12 volt powered Pro Air unit?

[cruising7388]

Originally Posted by DUTCH in Atlanta

Coachmen is now offering the Pro Air 20K BTU 12 Volt A/C on the 2019 Galleria instead of the Dometic Low Profile13,500 A/C, which is no longer offered. It's a very expensive option, but it's either that or no A/C.

Anyone have experience with this 12 volt powered Pro Air unit?

Roadtrek offers the Pro Air but it is an under chassis unit and the one I saw in operation had an outside noise level that seriously competed with the noise of an Onan generator.

The Pro Air option offered on the Galleria is a different breed of cat. It is roof mounted with five speeds and is apparently even quieter in operation than the conventional Dometic AC it replaces. If demanded by the customer, the Galleria can be optioned with the 120V Dometic AC but IMO the 12V roof top Pro Air design is the much better choice.

[DUTCH in Atlanta]

Thanks cruising7388. I was told by one of the managers at the Coachmen factory that the Dometic unit is no longer offered, and that the 12 volt Pro Air is quieter and more powerful; although I can't find anything from Coachmen that gives any details on it.

At $3,375 it better be really something; and while they removed the Dometic unit from the Convenience Package, they did not reduce the package price.

[cruising7388]

Originally Posted by DUTCH in Atlanta

Thanks cruising7388. I was told by one of the managers at the Coachmen factory that the Dometic unit is no longer offered, and that the 12 volt Pro Air is quieter and more powerful; although I can't find anything from Coachmen that gives any details on it.

At $3,375 it better be really something; and while they removed the Dometic unit from the Convenience Package, they did not reduce the package price.

This is a new release. Coachmen is unique in that they implement rolling changes during a model year while typically most builders release them with a new model year. But LTV does this by adding a .5 suffix to a model year for rolling changes.

Roadtrek charges $4420 for their Pro Air but it's a 30k BTU unit and unless you need a meat locker environment, IMO it's overkill. I think the 20k BTU Pro Air now offered on the Galleria hits the sweet spot. Since it is a 12V unit, it looks directly at the batteries and avoids the conversion losses inherent in inverters and DC-DC converters. The Crossfit now is available with the Xantrex battery system which was introduced on the Galleria so I wouldn't be surprised to see the the Pro Air design migrate to the Crossfit and ultimately to other B upbuilders.

There are some tradeoffs. Eliminating roof air for an under chassis unit can shave about 8 inches inches off height which can help tucking one of these coaches into a garage. Also, this relocation opens up space for additional rooftop solar panels.

[DUTCH in Atlanta]

In addition to the Pro Air A/C, the 2019 Galleria has a list of new options on the Sept 24 Price List - some potentially very interesting, although quite expensive. Hopefully, Coachmen will sometime soon provide literature with details of what they are and and what they do.

[da1ton]

If you have a Galleria with the 12v ProAir A/C but you do not have a Lithium Galleria, is it necessary to have 30Amp (or generator) to run the A/C or can it safely be done if you are plugged in to a 15Amp service? Since the A/C runs on 12v, it seems that you wouldn't need 30Amp.

[Boxster1971]

Originally Posted by da1ton

If you have a Galleria with the 12v ProAir A/C but you do not have a Lithium Galleria, is it necessary to have 30Amp (or generator) to run the A/C or can it safely be done if you are plugged in to a 15Amp service? Since the A/C runs on 12v, it seems that you wouldn't need 30Amp.

I've looked at the Coachman Galleria brochure and it's not clear how the standard 330AH AGM batteries get charged when plugged in. It does indicate a 2000W inverter, but it does not say if it is also a charger. I would assume it is.

My 200W Magnum inverter/charger will put out 100A DC from charger with a 15A AC input. That should be enough to run the ProAir 12V DC A/C system in all but the warmest conditions according to their spec sheet attached. But you would not be able to handle much of an additional 120VAC load in the van when plugged into a 15A 120VAC circuit. Pretty much the way my standard 120VAC A/C systems works now, when I'm plugged into a 15A AC source.

[Bud]

Hi Boxter,

I don't understand. The amps used is determined by the outside temperature or inside? Not the compressor on or off? Obviously ignorant here, please help.

Bud

[Boxster1971]

Originally Posted by Bud

Hi Boxter,

I don't understand. The amps used is determined by the outside temperature or inside? Not the compressor on or off? Obviously ignorant here, please help.

Bud

The ProAir data is for "ambient", since the whole unit sits on the roof outside I assume they are listing those current draws for the outside temps listed in the sell sheet I attached.

- - Mike

[Bud]

Originally Posted by Boxster1971

The ProAir data is for "ambient", since the whole unit sits on the roof outside I assume they are listing those current draws for the outside temps listed in the sell sheet I attached.

- - Mike

I still don't understand. How are amps used determined by ambient temperature. Is it based on assumptions about compressor use over time, compressor on and off.

Bud

[Boxster1971]

Originally Posted by Bud

I still don't understand. How are amps used determined by ambient temperature. Is it based on assumptions about compressor use over time, compressor on and off.

Bud

Outside Temperature
The amount of heat and the rate at which it transfers depends upon the temperature difference between the outside air and the refrigerant. The lower the temperature of the outside air, the more cooling is done by the heat exchanger, instead of the compressor. When the outside air temperature increases, the air-conditioner works harder to cool the home because the compressor works more.

https://sciencing.com/can-outside-te...-ac-23326.html

[Bud]

Mike, need it dumbed down.

"the air-conditioner works harder to cool the home because the compressor works more."

Your link said "works harder ", does that mean turns on more, runs more?

[Boxster1971]

Originally Posted by Bud

I still don't understand. How are amps used determined by ambient temperature. Is it based on assumptions about compressor use over time, compressor on and off.

Bud

The difference is not from the duty cycle (on and off). It is because the compressor needs more power to change the state of the refrigerant when the ambient temperature is higher.

The electric power input to an air-conditioner compressor increases with increasing outdoor air temperature due to the increasing discharge pressure caused by the decreasing heat transfer capacity of the condenser in the air-conditioner.

- - Mike

[Bud]

Originally Posted by Boxster1971

The difference is not from the duty cycle (on and off). It is because the compressor needs more power to change the state of the refrigerant when the ambient temperature is higher.

The electric power input to an air-conditioner compressor increases with increasing outdoor air temperature due to the increasing discharge pressure caused by the decreasing heat transfer capacity of the condenser in the air-conditioner.

- - Mike

Thanks, feeling foolish as I should have picked that up somewhere in the last upteen years. I'll start reading as opposed to more questions.

[Kab449]

I’m no expert on ProAir but know that when a compressor runs off DC it can vary current draw through variable compressor RPM’s depending on the cooling requirements ie outside ambient temperature and humidity.
I have mini split heat pumps in my house that work by inverter technology. They change AC to DC and the compressor runs at many different speeds based on demand.
I’m thinking this technology is creeping into our RV’s.

[Boxster1971]

Originally Posted by Kab449

I’m no expert on ProAir but know that when a compressor runs off DC it can vary current draw through variable compressor RPM’s depending on the cooling requirements ie outside ambient temperature and humidity.
I have mini split heat pumps in my house that work by inverter technology. They change AC to DC and the compressor runs at many different speeds based on demand.
I’m thinking this technology is creeping into our RV’s.

Yes - that is the technology - I sure hope it is widely adapted by the RV industry. Inverters and variable speed compressors are making the newest heat-pump systems very appealing.

[Kab449]

The mini splits in my house are amazingly efficient. They heat and cool great and cost very little to operate.
The RV industry definitely needs to embrace this technology.

[Bud]

I have a heat pump in my B but have never used it. If I have shore power, why wear out the thing? When I can use an inexpensive electric heater down on the floor where the heat should .........

I must be missing something.

Bud

[gregmchugh]

There wouldn’t be much advantage to using a heating option on a split AC in an RV since you always have a higher output heater available. I suppose when the temp is mild and you have shore power it might make some sense.

[Kab449]

The current trend in class B RV’s is no propane and no generator. The are putting Lithium Battery packs in them to drive a 12 volt AC unit. The DC motor driving the compressor lends itself to increased efficiency to make that possible. The fact that the heating side is possible is just a plus.
That is the context of my reply to this thread.