Recommendations for Mini-Split Heat Pump System

[Pnw_steve]

I have seen a few Pioneer mini-splits installed in RV's. There are a handful of folks over at www.skoolie.net that have mini-splits in their converted school buses. You might pop over there and pose the same questions.

I will be ordering two Pioneers for mine next month.

 

[Samsonite801]

Dave Poz has a video about installing one.

It’s linked in this thread:

Who's installed a Mr. Cool DIY?

Just curious how it went and how well it works. Electrical looks like the biggest pain. Seems odd to not have to vacuum out the lines -- are the lines pre-vacuumed and "pierced" during installation? Having a big wound up pile of left-over copper coolant lines seems unsightly, but as it's the...

diysolarforum.com

I really liked the Mr Cool DIY with the pre-charged line-sets... I installed the 24,000 BTU model in my old shop at the residence I just sold this Summer and it had been great, power bill hardly went up, and was as hot as I wanted in the Winter and as cold as I wanted in the Summer (plus with the extra BTU I calculated, it had fast recovery when you opened and closed the garage door for a bit), didn't have to call HVAC guy to install, it was simple, came with a wireless phone app and a hardware IR remote control, operates very quietly, hardly notice it running.


I just glued the 4 cement blocks down to the slab with heavy duty construction adhesive to keep it there, but the extra height kept it out of the snow.


I think for my new off-grid home plan if I get a mini-split system for it, I might look into the 48v DC system from Hot Spot Energy:

Solar Air Conditioner | 48V DC Solar Air Conditioners | Compare all-DC and AC-DC Hybrid Solar AC Units

 

[JDTravels]

We have been running a 240V cassette mini split (Senville) in a 40ft RV for a few years now. Setup: 1800W solar, 200AH lithium battery at 48V, Victron Quattro (x2) inverters (all electric rv). We have been in 105 degree Arizona heat and and 23 degree Colorado mountains. Air: If you can get ahead of the heat load in the mornings.. we saw watts ranging from 450 to 625 during the day. The biggest issue was making sure the battery had enough power to run the air into the evening until things cooled down. Outside St Louis I really appreciated the dehumidifier function..ran a consistant 640 watts. Heat: since my unit is in the ceiling.. the heat tends to stay high.. my feet stay chilly. I found that the 2 inverter losses went above the savings in 240V vs 110V mini split. We are in the process of building a new rig and will have a 110V mini split heat pump with the main heat provided by catalytic heater backed up by furnace. I will be doing the install but will have an heat/AC person shorten the lines and flare the ends. I just don't want to have the excess line set hanging on the back of the rig. Hope this helps..

 

[Bill Taylor]

I bought 12 "AUX" brand mini splits fron Ebay a year ago. 12,000 BTU, 120 volt, quite as a church mouse. Less than $500 each delivered. I installed six around my property, family and friends got the rest. Super easy installation. No problems with any of them. The main one in my living room pulls 1500 watts @ 115°, and worked hard to keep 700 square feet of my house cool. I'm not complaining about that. I probably should have got a larger one considering the size of the room it has to cool. Overnight at 80°, it pulls about 500 watts or so. It's an inverter so it slows down, it never totally shuts off. In the winter, it produces heat surprisingly well. It pulls around 600 watts at a maximum. I am totally thrilled with them

 

[Loadtoad]

I have my Senville 9000 btu running right now on my 7 x 16 cargo conversion. Puts out plenty of heat. At full bore it was pulling 7.5 amps according to my clamp meter. Works great in the summer also.

 

[mckennab]

That's a neat looking solution. Would you recommend the Senville? Nice trailer btw.

 

[Loadtoad]

That's a neat looking solution. Would you recommend the Senville? Nice trailer btw.

The mini-split has survived about 4000 miles on the road and everything working fine so far.

 

[Cpjlincoln21]

Can you tell me how many watts that 12,000 BTU Mr Cool unit is drawing when it is on? I was looking at getting the AC300 and two of the B300 batteries for it but I wanted to make sure it would run the AC for an hour or two at night if needed. The rest of my draw is very low. Some lights and a smart TV.

Earlier this summer, my girlfriend and I installed a Mr Cool Model DIY-12-HP-WMAH-115B, DIY-12-HP-C 12000 btu minisplit heat pump (heats/cools) in my 780 sf, well insulated off-grid cabin in the Ouachita Mountains of western Arkansas.

lit was a fun project and although I have only used it in the heating mode, it has worked very well so far.

Since it has a variable speed compressor, the amperage draw has varied. So far, I’ve seen the amperage draw range from 3 to 11 amps on my Trace SW4024 inverter. This may also include, at times, other items on the system.

My solar array size is 3,725 watts and I have 18 Duracell 105 Ah AGM batteries for storage.

The battery bank is new and so far, all is well. I was a bit concerned about my system drawing too many amps and shutting down, but that has happened only once - today. Murphy’s Law!

In addition to the inverter and battery bank mentioned, I have a Trace T-220 transformer connected to the output of the inverter allowing me to run my well pump and GE GeoSpring 50 gallon water heater.

The job of installing the minisplit was fairly challenging, but certainly doable. The hardest part for me was adding the additional circuit and mounting the holding bracket for the unit.

I’ll try and send a photo of it in a moment. By the way, making the connections with the pre-charged coolant lines was easy.

The unit really seems to do a great job cooling my cabin. So far, I’ve mostly run it during the day and shut it off at night. The cabin stays comfortably cool. I’m glad that I did it. It is super quiet.

 

[Cpjlincoln21]

Good point. I was actually thinking about installing a 240V Mr Cool heat pump, but when I did the estimated load calculation on my 700 sf cabin, it seemed like the unit would have been too big.

Its really rewarding at times to try new projects in an effort to push a solar powered off-grid system to its’ limits. I believe that as the technology continues to evolve, it’ll get even easier and more fun to go off-grid, without giving up many of the luxuries of a conventional home.

I’d like to hear from other members who have “pushed the envelope” too. They may be doing a fun project that I need to try!

Do you know how many watts the 12,000 unit is using when it is heating and also when it is cooling? Thanks!

 

[SolarfortheOuachitas]

Do you know how many watts the 12,000 unit is using when it is heating and also when it is cooling? Thanks!

I don’t know exactly because it has a variable speed compressor and fan and so amperage draw and wattage varies. Also, I don’t have a kill-a-watt meter on it because it’s on a separate circuit with its own disconnect.

However, I’ve seen it pull as many as around 8 or 9 amps at 120 volts. So that’s approximately 960 to 1080 watts.

I read the amperage draw from my inverter in my power house and this is just a good guess.

At other times, when the Mr Cool unit has met its desired temperature and isn’t working hard, it pulls very few amps/watts.

One thing that I’ve noticed is that the thermostat seems not to be calibrated correctly because I usually have to set it a bit higher to get it to heat the way I like it, but then I’m still learning.

Overall, the units a really nice and work great.