Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > RV SYSTEMS AND TECHNOLOGIES FORUMS > Going Green
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 03-12-2020, 02:02 PM   #43
Senior Member
 
glennwest's Avatar
 
Join Date: Mar 2009
Posts: 1,596
The 12k units 48v are very energy stingy. The 15-24k goes down in efficientcy though. Still better than 240v though.
__________________
2003 Teton Grand Freedom. 2006 Freightliner Century 120 with Detroit 14L and Ultrashift.2016 Smartcar carry on deck. Full time going from job to job. Building and maintaining plants across the USA. Sold 2006 Mobile Suites 32TK3
glennwest is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 03-12-2020, 08:48 PM   #44
Senior Member
 
Join Date: May 2019
Posts: 877
For you guys that actually have and use a mini split in your rv...

I have a little 21 ft travel trailer that I have room to mount an indoor unit on the rear wall (below the window).

Should a 12,ooo btu unit cool my trailer in the deep south?
Camper25 is offline   Reply With Quote
Old 03-12-2020, 09:13 PM   #45
Senior Member
 
okmunky's Avatar
 
Solo Rvers Club
iRV2 No Limits Club
Join Date: Feb 2011
Location: Yuma County, AZ
Posts: 10,868
Quote:
Originally Posted by Busskipper View Post
This help? - https://sharkaire.com/12-V-DC-Ductless-Mini-Split

They do work on Solar 12/24 volt systems - if cool is what you seek then you need to also look at the Elevation you are Parking the RV.

Leadville, Colorado comes to Mind. 10,000 feet and sun with low humidity - Pretty much checks all the boxes. Tha as a home base in the Summer with Buena Vista and points South in the Winter.

With an RV, sometimes logic just beats engineering. -

JMHO,
Unfortunately I get high altitude sickness above 7000 feet. I am excited, though, to research the link you provided for the DC air-conditioning. I’m building a 240 sq ft off grid tiny home in southern Arizona. Thanks!
__________________
Barb (RVM18) with Morkies Lily & Bebe RIP Sena FMCA#F466348
"Homer" ‘11 Shasta Cynara, pulling "Ranger" '97 Ford Ranger toad
The Journey is Our Destination. Full-timer May 2011 - July 2021
[SIGPIC][/SIGPIC]
okmunky is offline   Reply With Quote
Old 03-13-2020, 08:33 AM   #46
Senior Member
 
glennwest's Avatar
 
Join Date: Mar 2009
Posts: 1,596
Quote:
Originally Posted by Camper25 View Post
For you guys that actually have and use a mini split in your rv...

I have a little 21 ft travel trailer that I have room to mount an indoor unit on the rear wall (below the window).

Should a 12,ooo btu unit cool my trailer in the deep south?
Should do great. One 12k kept living area cool in South Texas. Added second for bedroom area. We have a clothes dryer in bedroom area also. We are 40'
glennwest is offline   Reply With Quote
Old 03-13-2020, 11:47 PM   #47
Senior Member
 
Country Coach Owners Club
Join Date: Jul 2019
Posts: 408
I'm seriously looking at two of the Hotspot Energy 12K 48V units and would love to talk to someone who has actually used them.
__________________
2000 Country Coach Magna 40', 2022 Ram Power Wagon
4380W Solar 38kWh LiFePO4 18k/12k/12k/9k LG Mini Splits
Cinderella Travel & Lots of Other Modifications
n0mad is offline   Reply With Quote
Old 03-14-2020, 08:21 AM   #48
Senior Member
 
glennwest's Avatar
 
Join Date: Mar 2009
Posts: 1,596
Quote:
Originally Posted by n0arp View Post
I'm seriously looking at two of the Hotspot Energy 12K 48V units and would love to talk to someone who has actually used them.
They are basically the same as the standard mini splits. Both use DC current for compressor. They vary the voltage to vary output. The 48v units don't convert ac to dc. This is what makes them more efficient. They are higher in cost due to supply and demand. So a 12k in 120v works same as 12k in 48v.
__________________
2003 Teton Grand Freedom. 2006 Freightliner Century 120 with Detroit 14L and Ultrashift.2016 Smartcar carry on deck. Full time going from job to job. Building and maintaining plants across the USA. Sold 2006 Mobile Suites 32TK3
glennwest is offline   Reply With Quote
Old 03-15-2020, 06:15 PM   #49
Junior Member
 
Join Date: May 2013
Posts: 21
Installing a Mini-Split in a motorhome could be a challenge … doable I suppose for a big enough motorhome, but still a challenge. But then, unless the M/S was specifically designed for bumping down the road, there would likely be frequent leaks and failures. It’s a great idea; I just haven’t ever seen it done. I’ll relate my experience.

Three years ago, I installed a single Fujitsu 9RLS3 Mini-Split (~ $1500) in my well insulated Eastern Oregon Mountain Cabin. The nominal rating is 9000 BTUs, but it’s rated to deliver a maximum 12,000 BTU/hr. cooling, and 22,000 BTU/hr. heating. That’s sufficient to both cool and heat my entire cabin.

By using a microprocessor with inverter (VFD) technology to drive the three motors (compressor, condenser fan, and evaporator fan) it is able to reach and maintain set points much faster than conventional units. There is no X5 start current; the motors are variable speed running at the precise speed called for by the microprocessor to maintain the setpoint. And they are very quiet.

It uses the newer R410a refrigerant whose higher pressure operating points enable higher efficiencies than the older R22 refrigerant. That makes it very economical to heat my living space of 950 sq. ft. down to 15 degF.

Summers in the mountains rarely get to 100 degF, so I don’t have much test data on it’s cooling capacity, but I’m guessing it would easily be able to maintain a 30-degree differential between the outside and the inside. That is, if it’s 110 out, it would maintain a maximum of 80 deg inside.

It requires a 240 Vac, 15A breaker. Run current at max capacity is about 7.5A (1800 Watts).

A min of 10’ vertical separation is recommended between the inside and outside unit to run the lines. Power is wired to the outside unit. A cable is then run to the inside unit. There are also two copper tubing runs, a 3/8” line for the low-pressure suction line, and a ¼” line for the high-pressure liquid line. When used as an A/C, it’s also necessary to run a condensation drain line from the inside unit to the outside.

The external unit comes already charged with the correct amount of refrigerant for the compressor and the 10’ lineset. Once all the connections are made, and before releasing the refrigerant, it’s necessary to use a vacuum pump to evacuate the lines of any moisture and contaminants to below 500 microns. Once the refrigerant is released, you’re done.

Most installations are done by HVAC techs, but I did mine myself … in which case, it’s important to know how to correctly make flare fittings that are torqued precisely to the right values (I have an electronic torque wrench). It used to be said that 60% of leaks are due to poorly installed flare fittings, however, with the newer higher pressure R410a, I’d guess it’s much higher. Both the fittings and flare tools for R410A are also special.
depler is offline   Reply With Quote
Old 03-15-2020, 09:10 PM   #50
Senior Member
 
Country Coach Owners Club
Join Date: Jul 2019
Posts: 408
Quote:
Originally Posted by depler View Post
Installing a Mini-Split in a motorhome could be a challenge … doable I suppose for a big enough motorhome, but still a challenge. But then, unless the M/S was specifically designed for bumping down the road, there would likely be frequent leaks and failures. It’s a great idea; I just haven’t ever seen it done. I’ll relate my experience.

Three years ago, I installed a single Fujitsu 9RLS3 Mini-Split (~ $1500) in my well insulated Eastern Oregon Mountain Cabin. The nominal rating is 9000 BTUs, but it’s rated to deliver a maximum 12,000 BTU/hr. cooling, and 22,000 BTU/hr. heating. That’s sufficient to both cool and heat my entire cabin.

By using a microprocessor with inverter (VFD) technology to drive the three motors (compressor, condenser fan, and evaporator fan) it is able to reach and maintain set points much faster than conventional units. There is no X5 start current; the motors are variable speed running at the precise speed called for by the microprocessor to maintain the setpoint. And they are very quiet.

It uses the newer R410a refrigerant whose higher pressure operating points enable higher efficiencies than the older R22 refrigerant. That makes it very economical to heat my living space of 950 sq. ft. down to 15 degF.

Summers in the mountains rarely get to 100 degF, so I don’t have much test data on it’s cooling capacity, but I’m guessing it would easily be able to maintain a 30-degree differential between the outside and the inside. That is, if it’s 110 out, it would maintain a maximum of 80 deg inside.

It requires a 240 Vac, 15A breaker. Run current at max capacity is about 7.5A (1800 Watts).

A min of 10’ vertical separation is recommended between the inside and outside unit to run the lines. Power is wired to the outside unit. A cable is then run to the inside unit. There are also two copper tubing runs, a 3/8” line for the low-pressure suction line, and a ¼” line for the high-pressure liquid line. When used as an A/C, it’s also necessary to run a condensation drain line from the inside unit to the outside.

The external unit comes already charged with the correct amount of refrigerant for the compressor and the 10’ lineset. Once all the connections are made, and before releasing the refrigerant, it’s necessary to use a vacuum pump to evacuate the lines of any moisture and contaminants to below 500 microns. Once the refrigerant is released, you’re done.

Most installations are done by HVAC techs, but I did mine myself … in which case, it’s important to know how to correctly make flare fittings that are torqued precisely to the right values (I have an electronic torque wrench). It used to be said that 60% of leaks are due to poorly installed flare fittings, however, with the newer higher pressure R410a, I’d guess it’s much higher. Both the fittings and flare tools for R410A are also special.
Thanks for the info. For what it's worth, I know of several mini-split installs on RVs, just none that have the detailed usage data I was hoping for. Most people I've talked to with them love them, but can only say that they're more efficient than a rooftop AC. A couple who do some loose tracking have told me they use less than half as much, but those aren't hard numbers. I have some hard numbers from one person who uses Victron VRM (the same system I use for logging off a Venus), but they aren't over a span of time. A few of them have used them for years without issues. New Horizons is actually adding them to new units they're building.

As for mounting, I know of a couple installs in gutted class A cargo bays but we don't have that option on our rig. I looked at heavily modifying the generator bay but it's all but impossible to get enough airflow into ours, and keep the generator there. So I'm having a welder come out tomorrow to build a special enclosure on the back of the RV that is mounted to the frame. The enclosure will consist of a rigid frame with solid steel surface, and a removable, fairly lightweight expanded steel cage with hinged door on top of it. I'm having a few "features" added, like some welded flag pole mounts, and configuring the door in such a way that it can fold down and be used as a 32x60" table. This is a more robust/custom solution than I've seen on other rigs that have them on the back. Being that the platform will have a solid connection to the frame (not a receiver tube with play) and will move as a unit with the entirety of the RV, that should keep the line set movement independent of the condenser to a minimum.

I'll be installing a 30A 240V breaker in a new sub panel off my AC junction box, and a disconnect switch inside the enclosure at the back of the RV. The condenser unit I picked out is pre-charged for the line set lengths I'm running, with a bit of extra, and I found pre-built line sets that are the appropriate lengths. That means that I should just have to leak test it and vacuum out the lines so greatly simplifies the install. I'll be buying the tools for building the lines, along with the the vacuum pump and manifold gauges, and other a few others to carry with me on the road if problems do arise, or arise during the install.

It's not a popular conversion, but I know of several successful cases. I'm excited to see how it works out for us. In the end I decided to put 30K of AC back in to replace the "30K" I'm taking out - I doubt the output of the Dometics.
__________________
2000 Country Coach Magna 40', 2022 Ram Power Wagon
4380W Solar 38kWh LiFePO4 18k/12k/12k/9k LG Mini Splits
Cinderella Travel & Lots of Other Modifications
n0mad is offline   Reply With Quote
Old 03-15-2020, 09:15 PM   #51
Senior Member
 
glennwest's Avatar
 
Join Date: Mar 2009
Posts: 1,596
What size unit you getting. My Pioneer 12k uses a 15 amp breaker. They would run on less. As far as power usage, the maufacturers list the wattage it uses.
__________________
2003 Teton Grand Freedom. 2006 Freightliner Century 120 with Detroit 14L and Ultrashift.2016 Smartcar carry on deck. Full time going from job to job. Building and maintaining plants across the USA. Sold 2006 Mobile Suites 32TK3
glennwest is offline   Reply With Quote
Old 03-15-2020, 09:45 PM   #52
Senior Member
 
Join Date: Aug 2019
Posts: 155
Look up New Horizons, they have installed a mini split in a 5th wheel. I believe they have a you tube video showing it in a show model they had in Florida.
cwall59 is offline   Reply With Quote
Old 03-15-2020, 09:59 PM   #53
Junior Member
 
Richard Qc's Avatar
 
Join Date: Aug 2019
Location: Québec, QC, Canada
Posts: 8
Check https://youtu.be/woZH85EiHNY
14:00 Power Consumption Par 2 - Examining Solar Charts - Data!!
Richard Qc is offline   Reply With Quote
Old 03-15-2020, 10:28 PM   #54
Senior Member
 
Country Coach Owners Club
Join Date: Jul 2019
Posts: 408
Quote:
Originally Posted by glennwest View Post
What size unit you getting. My Pioneer 12k uses a 15 amp breaker. They would run on less. As far as power usage, the maufacturers list the wattage it uses.
LG LMU30CHV (30K BTU Outdoor Unit)
2x LG LMN159HVT (15K BTU Indoor Units)

EER 13
SEER 22

Click image for larger version

Name:	Screen Shot 2020-03-15 at 21.28.03.png
Views:	38
Size:	89.8 KB
ID:	278145

This will use more electricity than the 2x 12K 48VDC units I was strongly considering. Sometimes I've felt the two Dometic 15K units aren't enough - and in the end I decided to compromise a little efficiency for more overall cooling. Regardless, this should be a massive improvement in consumption over the units we have, especially since we can just run the bedroom unit at a very low load overnight. And I'm hoping they'll be a notable improvement over the 30K worth of Dometic cooling we have - I suspect we incur large ducting losses in the ceiling and that the units might be a little overrated at 15K.
__________________
2000 Country Coach Magna 40', 2022 Ram Power Wagon
4380W Solar 38kWh LiFePO4 18k/12k/12k/9k LG Mini Splits
Cinderella Travel & Lots of Other Modifications
n0mad is offline   Reply With Quote
Old 03-16-2020, 07:26 AM   #55
Junior Member
 
Join Date: May 2013
Posts: 21
"That means that I should just have to leak test it and vacuum out the lines so greatly simplifies the install. I'll be buying the tools for building the lines, along with the the vacuum pump and manifold gauges, and other a few others to carry with me on the road if problems do arise, or arise during the install."

Reply:
First, let me say I'm impressed. IMHO, you're doing all the right things. OK, please know that the vacuum pump is the only thing I used or needed to install my system. No gauges, or nitrogen bottle used or needed.

While I have the manifold gauges and hoses, they can’t be used for checking or adding refrigerant to my Fujitsu. With conventional systems, that's usually done by either checking the evaporator’s superheat, or the condenser’s subcooling temps against a chart, but that's not recommended for the M/S. The reason I'm told is that for proper operation, the unit’s come ‘critically charged’ from the factory, and the only factory recommended way to check levels is to first recapture the refrigerant, then to weigh-in the correct amount (as specified on the unit's name plate). That’s essentially the definition of a ‘critically charged' unit. Of course, that’s also the procedure to add refrigerant after 3 – 7 years of use (all systems will leak a little over time ... which could be the case with your Dometics).

I also don’t happen to have scales or a recovery unit (expensive). I'm a small time DYI operator. But I've never had a call-back either.

I didn’t do a nitrogen leak test before releasing the refrigerant, mostly because I don’t do enough installations to buy a nitrogen bottle. I reasoned that by ensuring my flare connections were properly made and torqued I’d be OK. Of course, if the inside unit came from the factory with leaks that’s something else … but sniffers (for hard-to-reach) and soap bubble tests can always be used to find refrigerant leaks in any case.

Again, the mini-split technology is different from conventional A/Cs. It’s hard for most old-school HVAC techs to get used to the new procedures as trusted old habits die hard.
depler is offline   Reply With Quote
Old 03-16-2020, 08:38 AM   #56
Member
 
Join Date: Sep 2011
Posts: 82
Quote:
Originally Posted by depler View Post
While I have the manifold gauges and hoses, they can’t be used for checking or adding refrigerant to my Fujitsu. With conventional systems, that's usually done by either checking the evaporator’s superheat, or the condenser’s subcooling temps against a chart, but that's not recommended for the M/S. The reason I'm told is that for proper operation, the unit’s come ‘critically charged’ from the factory, and the only factory recommended way to check levels is to first recapture the refrigerant, then to weigh-in the correct amount (as specified on the unit's name plate). That’s essentially the definition of a ‘critically charged' unit. Of course, that’s also the procedure to add refrigerant after 3 – 7 years of use (all systems will leak a little over time ... which could be the case with your Dometics).

I also don’t happen to have scales or a recovery unit (expensive). I'm a small time DYI operator. But I've never had a call-back either.

I didn’t do a nitrogen leak test before releasing the refrigerant, mostly because I don’t do enough installations to buy a nitrogen bottle. I reasoned that by ensuring my flare connections were properly made and torqued I’d be OK. Of course, if the inside unit came from the factory with leaks that’s something else … but sniffers (for hard-to-reach) and soap bubble tests can always be used to find refrigerant leaks in any case.

Again, the mini-split technology is different from conventional A/Cs. It’s hard for most old-school HVAC techs to get used to the new procedures as trusted old habits die hard.
This is mostly overkill. I have installed and maintained several mini splits in several homes. Flare fittings can be made from ordinary copper pipe flaring tools (mine was dirt cheap so nothing special). Use Nylog Blue sealant to the flare face for leak insurance. Never have used a torque wrench on a flare fitting. Gauges can be used to charge or top off refrigerant levels. It is true that to gain maximum efficiency the refrigerant should be removed and reweighed into the system, but not that big a deal if you don't. I have vertically coiled freon lines on my oldest unit with no ill effects. Minimum line lengths are listed because the units come precharged for a specific line length. If you cut the lines you will be overcharged. That can be overcome by recovering some refrigerant to the correct operating suction pressure. If you release refrigerant to the atmosphere you will increase global warming ten fold (or some similar estimated made up number).
__________________
2017 F350 DRW
2017 Momentum 388
sgrol is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mini Split on NH Prof_Lube New Horizons Owners Forum and NHOG 64 08-12-2020 04:12 AM
Mini Split AC Install Limegreencj5 Class A Motorhome Discussions 5 05-01-2019 04:38 AM
Mini split a/c heat pump SAS30 RV Systems & Appliances 13 10-18-2017 07:18 PM
Mini Split AC? bilb2765 5th Wheel Discussion 8 08-05-2016 06:25 PM
Replace TruAir with mini split AC? NuthinFancy Winnebago Industries Owner's Forum 19 02-27-2016 06:59 PM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 11:27 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.