DC Air Conditioner (minisplit/rooftop/anything)

[curiouscarbon]

By using the photovoltaic panel as the evaporator for a heat pump, efficiency can be increased...

Heat Pumps Harmonizing Heating and Cooling Needs

Hello, People like lower temperatures for some times, and higher temperatures for other times. It seems to need a lot of electricity energy.. Heat pumps, especially in the form of refrigerant based compressor systems, and also peltier based systems, are capable of controlling heat flow with...

diysolarforum.com

More recently, however, PVT modules coupled with refrigeration system have been gaining attention too. Here, the compressor is powered by the PV panel while thee PVT module itself also serves as the evaporator of the refrigeration system. The evaporator cooling effect lowers the solar cell working temperature and improves the PV efficiency. This arrangement can give an even better performance as compared to air or water cooled systems.

Numerical Study of Integrated Solar PhotovoltaicThermal Module with a Refrigeration System for Air-Conditioning and Hot Water Production under the Tropical Climate Conditions of Singapore​

Proposed System
The proposed PVTR system produces electricity, hot water and air-conditioning at the same time by integrating solar PVT and VCR systems. Electricity is produced by the PV cells, while the refrigeration system produces hot water at its condenser and air-conditioning (cooling) at a section of the evaporator through a fan coil unit (FCU). At the same time, the refrigeration system also cools the PVT modules to optimize their performance

The results show that attractive electrical and thermal perfor- mance can be achieved with a maximum annual cooling COP of 9.8 and a heating COP of 11.3. The PV e±ciency and power saving were 14% and 53%, respectively.

 

[Lt.Dan]

Wow, they actually got back to you? I have two emails, a phone call, and questions to a member in another thread to someone that claims to say “my company”, please reach out, and nothing in response.
But, you are right, it does seem to have some good specs and I have found Coachman Galeria videos that seem to prove it to be quiet. Not sure on the power consumption because in the videos, they say ‘ look at the low draw! But the solar is on’
Damnit , turn the solar off and show us what the unit is drawing!!!!!
All a moot point for me as as much as I would like a 12 volt native system, it won’t fit between my solar panels, skyline, and roof vents.
recpro.com seems to only be selling the 12 volt version. It comes from premierproducts.net They have a 48 volt version on their site but they are the ones that have been unresponsive to me.

I think I’m back to a mini split

Premier Products is who I emailed, and they got back to me very fast. The President got back to me first, and CC'd the Vice President to answer my questions, and the Sales manager to get me pricing. Both of them got back to me and answered questions and got me pricing within the next 10 minutes. Me and the Vice President have had a few emails back and forth since.

Premier products does a good job at laying it out plain and simple, with a graph showing watt consumption at a given ambient temp, comparing typical 110v AC units, other 12v units, and theirs. Like you said, I've seen so many companies claim "Look, only 80 amps!" But it means absolutely nothing. You dont know what the ambient temp was, or if the battery voltage was 11 volts, or 14.6 volts, etc. Garbage.

 

[Lt.Dan]

Ok, so heres the beans;

The 48v model from Premier Products costs $2695, not including shipping

It is advertised at 22,000 BTU, but they say the term "BTU" is pretty vague, because they can claim the BTU rating of their highest performing part in the unit. He did say it was very comparable to my existing Colman Mach 15 units, and i should expect the same performance.

The unit does bolt into an existing 14"x14" Cutout, meaning it is a drop in replacement for existing roof AC's. I've seen too many that needed 14.25"x14.25", which is unreasonable to me.

It is an AC ONLY unit, and they do not offer a heat pump/heat strip option.

It does will work with my existing ducting in the trailer, and no major modifications have to be made. This would have been another deal breaker for me because the ducting is an important aspect in my mind. Only down side in my situation is it will not work with the 3x RVAirflow Styrofoam units that I purchased to improve my old Coleman units.

They do offer a remote digital control panel, sold separately, and the AC unit does work with Firefly Control system, but it will not work with my existing LCI One Control panel to control the AC unit.

The guys seem very nice and helpful, they are pretty quick to respond, and I will add a few emails here if someone would like to inquire with other questions/purchases:
hvacsupport@premierproducts.net - The original email i asked questions to.
eric@premierproducts.net - President/CEO
carl@premierproducts.net - Vice President
brandon@premierproducts.net - Executive Sales Director

 

[K8MEJ]

What's the power draw for those? Max and typical? Also, in your situation are you saying one of the PP 48v units is equal to ONE of your Coleman units or one PP 48v unit is equivalent to all three of your Coleman units?

I guess I'm trying to understand if you need one or three. I'm assuming all three, for nearly $9,000?

 

[Lt.Dan]

What's the power draw for those? Max and typical? Also, in your situation are you saying one of the PP 48v units is equal to ONE of your Coleman units or one PP 48v unit is equivalent to all three of your Coleman units?

I guess I'm trying to understand if you need one or three. I'm assuming all three, for nearly $9,000?

Max power draw varies depending on outside ambient temp. But its typically 40% less than my existing AC. And 1x PP 48v unit is equivalent to 1x Coleman Mach 15 in terms of cooling efficiency and even in CFM rating. Only difference is actual power draw.

I would need 3x and that totals to $8085+shipping.

BUT, since they dont offer heating, then I would probably only get 2, and put one in the bedroom, and one in the garage, and then leave my Colman Mach 15 in the living room strictly for the heat pump feature.

That, or rely on heating from little space heaters or my propane furnace.

 

[richard cabesa]

Max power draw varies depending on outside ambient temp. But its typically 40% less than my existing AC. And 1x PP 48v unit is equivalent to 1x Coleman Mach 15 in terms of cooling efficiency and even in CFM rating. Only difference is actual power draw.

I would need 3x and that totals to $8085+shipping.

BUT, since they dont offer heating, then I would probably only get 2, and put one in the bedroom, and one in the garage, and then leave my Colman Mach 15 in the living room strictly for the heat pump feature.

That, or rely on heating from little space heaters or my propane furnace.

Thanks for reporting back Lt.Dan, this thread has got legs?.
Brandon finally got back to my questions in a thread at https://sprinter-source.com/forums/index.php?threads/100929/

He cleared up a few things there but I still have a few questions. They will have to wait as we are hitting the road for a bit. All cool coastal areas so we won’t need the air.

im hoping to narrow down the right unit for us by this winter to have it installed for Spring 2022 travels

 

[Moltensurf]

I'm installing an LG Mega 115v series 12K BTU mini split in my travel trailer this weekend. It will run off my Victron inverter. You can buy cheaper mini splits on Amazon. I didn't find any DC (12, 24, or 48 volt) air conditioners that were cost effective. I can add two more batteries and more solar to my roof PLUS the 115v mini-split for the same or less than trying to use one of the DC air conditioners.

If my rooftop A/C hadn't died two weeks ago I might be inclined to roll the dice and try one of the cheapie units from Alibaba but I just couldn't work up the nerve to risk it, let alone the time it would take to get here.

Do you have an inverter in your set up? If so, maybe you could consider traditional residential mini-splits that run of alternating current.

where are you mounting the outside unit?

 

[K8MEJ]

where are you mounting the outside unit?

 

[Lt.Dan]

Does that thing bounce at all? Or is it pretty sturdy?

 

[Jims94vmx]

If bumper is only source for attachment i would strongly look at reinforcement.
Seen too many pics of bike racks failing on bumper.....

 

[K8MEJ]

Does that thing bounce at all? Or is it pretty sturdy?

It doesn’t move at all relative to the bumper. I think that’s what you mean. It’s very firmly attached. The whole thing, apparatus plus outside unit, weighs less than 100 pounds. We completed a 1,000 mile road trip recently, along with a number of shorter trips with no issues. I was worried after traveling about 5 miles down a dirt road in Northern Michigan but that was over a month ago.

 

[Tuckles]

View attachment 62280View attachment 62281View attachment 62282View attachment 62283

Any pic's of the inside install?

 

[Bluedog225]

Great thread. Subscribed.

 

[curiouscarbon]

Faraday cage - Wikipedia

en.wikipedia.org

• A microwave oven utilizes a partial Faraday shield (on five of its interior's six sides) and a partial Faraday cage, consisting of a wire mesh, on the sixth side (the transparent window), to contain the electromagnetic energy within the oven and to protect the user from exposure to microwave radiation.

modern designs ensure minimal leakage. still probably good to not hold one's face up to the window the entire time.

 

[S Davis]

If there is any movement of the flair joints they will eventually fail, and you don’t want to see what a 1/4” flexible line with 550 psi of refrigerant coming out the end looks like.

 

[curiouscarbon]

vibration related fatigue failure of the refrigerant lines leading to a leak is something that i would want to mitigate in a configuration like this.

what sorts of easy methods could be used to bolster against the vertical bumps of the road?

for maintenance, easy replacement would be nice. otherwise some sort of spray foam popped into my head, at the joints.

 

[richard cabesa]

For the rubber hose application, I would use male/female o-ring fittings from

Cold Hose

AC Hoses, Hose Kits and Fittings, AC hose repair

coldhose.com

These types of fittings are used in many mobile applications without problems. Use the steel ones not aluminum. Stay away from copper flair and you will have no work hardening problems

 

[eXodus]

vibration related fatigue failure of the refrigerant lines leading to a leak is something that i would want to mitigate in a configuration like this.

what sorts of easy methods could be used to bolster against the vertical bumps of the road?

Add Shock absorbers in the RV

For whatever reason most North American trailers come without any dampers. Any Motorhomes shock are undersized from the factory.

There are now also SumoSpring for trailers https://www.superspringsinternational.com/trailer-sumosprings/

I had the SumoSprings under my Van (sold), my Class A Motorhome and my Pickup. And now under my horse trailer - makes the ride sooo much smoother. Not sure how people can live without those

Not only will the A/C last longer - but everything else inside the vehicle.

 

[eXodus]

48V Quiet Roof Heatpump. Air Conditioner

48V Air Conditioner for RV - 13.5K AC Unit with Heat Pump and Remote Control Non-Ducted

Are you tired of sweating through those hot summer days in your RV? Look no further, because RecPro has the perfect solution for you: our RV Air Conditioner with Heat Pump.

www.recpro.com

Not cheap and don't know how efficient - but that would be a pretty easy direct drop in to get around a big inverter.

 

[G00SE]

48V Quiet Roof Heatpump. Air Conditioner

48V Air Conditioner for RV - 13.5K AC Unit with Heat Pump and Remote Control Non-Ducted

Are you tired of sweating through those hot summer days in your RV? Look no further, because RecPro has the perfect solution for you: our RV Air Conditioner with Heat Pump.

www.recpro.com

Not cheap and don't know how efficient - but that would be a pretty easy direct drop in to get around a big inverter.

The AC version of These are great. Much less peak surge. Smoother demand as well. Best benefit. A 7-10 decibel drop in noise