Off Grid A.C.

bobdelso

Solar Enthusiast
Joined
Aug 11, 2020
Messages
75
Back to Solar talk:

Thad, I'm leaning toward following your lead and buying Pioneer, a name that comes up often and has your positive feedback. In one of your earlier notes you said that it was using 1100 watts. How did you get that exact measurement? Was there any variation or was the 1100 constant?
I've seen a killawatt meter used on some different mini split units. The 6000-8000 BTU units use arund 600-700 watts of power. The 9-10k BTU units use around 900 watts. A 12k btu will use around 1100.

The SEER rating will affect those numbers, higher the better.

If you've got a good sun spot, 1200-1400 of solar will cover you for a 8k BTU unit. Most tinyhomes are good with 1 8kbtu unit, if your in a bigger house (but still small) you might need a 10-12k unit. Units with 2 heads can also be nice, but spendy.
 

Off Grid Thad

Pound to fit, paint to match.
Joined
Nov 18, 2020
Messages
56
Location
Cascade Foothills
Late reply. Sorry.
It usually starts at about 450 watts at around 10am when I turn it on and ramps to 1k by 12pm when it gets hot enough. Most it has ever taken was 1200 on turbo mode. My panels put out 2100 watts at peak out of the 3200 of their rated numbers. So the battery stack gets a constant charge at peak sun. I have 10 bats of the Lishen 272’s in 12v.
Where we are, the charging sun cut down at 4 and is lost at about 530pm right now. The AC runs till 9 or 10 pm. It is all a relatively new installation so the bats never get a full up charge by the end of day. I’d guess that without any throttling it gets to maybe 85% then down to 55 or 60% by the time I shut it off.
Our inverter is an Outback 2812 that does not do 220v only 110. We just bought the biggest 110v unit they had. After 12k btu it goes to 220v.
So far it gets a few more watts every day than they give up. It should not take long to get the 90% mark where charge should go to float. It has been in the upper 80’s and lower 90’s since I put it in and runs near max from 12 to 8 pm.
Hope this helps.
Measurements come from an Outback set up with the Mate 2 as a monitor. It does not give an accurate state of charge but it does have good monitoring of in vs out with 3 shunts.
 

TC McClure

New Member
Joined
Jun 27, 2021
Messages
18
Thanks for the info. Here's my concern. The great room in my log home is 700 SF with a 16 foot ceiling. I have the extra power to run one 12000 BTU mini split at a time. 700 SF exceeds the specs of most 12K BTU models. Our comfort level is around 78 degrees F. Would there be a way to calculate the effectiveness of a 12K BTU unit in this size space>
 

Off Grid Thad

Pound to fit, paint to match.
Joined
Nov 18, 2020
Messages
56
Location
Cascade Foothills
If I had mine set to 78 it would draw about 600 watts max. Mostly 400. Rainy day here and very muggy humid. Drawing 300 in dehumidifier mode.
 

Mcgivor

Solar Addict
Joined
Jul 24, 2021
Messages
187
Having enough PV to support the A/C as well as the needs of the battery, especially if deeply discharged the previous night, a few days if heat with limited PV can result in multiple days of partial discharge, this is extremely hard on LA banks, having generator support is beneficial during such times.

All too often the assumption that the A/C will only use the excess energy is made, without consideration of passing clouds, which can take large chunks of capacity that need to be replenished, to the array needs to be capable of doing both similtaniously. This along with the window of opportunity, the two hours before and after noon, usually A/C is needed later in the day when PV input diminishes so added battery capacity may be needed.

Personally I operate two systems, each capable of supporting a 9000 BTU A/C unit during the day, but I found it to be a loosing battle against the sun, so I only use it after sunset to take the edge off and remove humidity, 30°C (86°F) is comfortable enough for me indoors, which is significantly lower than outside. My sleeping temperature is 28°C (82F) for this my Diakin unit runs overnight mostly at 150W cycling, or off after midnight if the sky is clear.

When living in the tropics it's best to become acclimatized because it's hot all year, many foreigners end up becoming mall rats to escape the heat, I live in the country on a farm spending most of my time outdoors working.

@TC McClure What battery capacity / nominal voltage and array capacity do you have ?
 

Mcgivor

Solar Addict
Joined
Jul 24, 2021
Messages
187
Thanks for the info. Here's my concern. The great room in my log home is 700 SF with a 16 foot ceiling. I have the extra power to run one 12000 BTU mini split at a time. 700 SF exceeds the specs of most 12K BTU models. Our comfort level is around 78 degrees F. Would there be a way to calculate the effectiveness of a 12K BTU unit in this size space>


The link below will help establish an estimate
 

Rednecktek

Solar Addict
Joined
Sep 8, 2021
Messages
771
I've been looking at doing the Pioneer 12k at my camp as well for the just under 400sq ft place. I only set my A/C to 65 because it won't let me go to 64. 😩 Once I finish with the utility power hookup I'm planning on making an off-grid setup that can handle the whole shebang when the utility power goes down.

Why am I doing both? Long story. Let's just say things have gotten MUCH better on the solar front in the last few years.

In other news, have you had any issues with the Pioneer unit? I work in HVAC on ships so I've already got the manifold and vacuum pump. Did you end up using the whole line length or shorten and re-flare? Had to get it repaired at all? Had to buy any parts? Can you run it without the remote control or are you buying a whole new unit if the remote dies?
 

Off Grid Thad

Pound to fit, paint to match.
Joined
Nov 18, 2020
Messages
56
Location
Cascade Foothills
No issues with system at all.
I cut the tubes to fit and flared, easy to do, but not absolutely required. They could have just been coiled and forgotten.
Parts I bought were for new power run, that would of course be all situational.
Unfortunately the remote is the only means of control.
We have 2500ah of 12v lithium and max draw for ac has been 1200 watts as it hets hotter the sun gets stronger. With 2600 watts of solar I can cool the house and charge back from running ac into the night.
 

rplarry

New Member
Joined
Feb 17, 2021
Messages
19
Thad, I just saw this thread today or I would have chimed in earlier. In the end you did exactly as I would have encouraged you to do. Last March I installed a 300ah lfp 48v battery bank after having agm's for 15years and could not be happier. I also installed 2 mini splits. I'm in northern Baja and it gets hot down here in the summer. With the new battery bank I am able to run the A/C (only one of the 2 A/C's is needed) all night long so I can sleep. In the morn I have used about 80% of my bank but with a 2hr run on the generator I can put most of that 80% back in and the sun then tops me off the rest of the day and I'm good to go the next night again. No more running the gen set all night long. I have ordered 16 more 320ah cells to augment my battery bank so I don't use so much of my capacity over night.
Good luck with yours.
 

TC McClure

New Member
Joined
Jun 27, 2021
Messages
18
Having enough PV to support the A/C as well as the needs of the battery, especially if deeply discharged the previous night, a few days if heat with limited PV can result in multiple days of partial discharge, this is extremely hard on LA banks, having generator support is beneficial during such times.

All too often the assumption that the A/C will only use the excess energy is made, without consideration of passing clouds, which can take large chunks of capacity that need to be replenished, to the array needs to be capable of doing both similtaniously. This along with the window of opportunity, the two hours before and after noon, usually A/C is needed later in the day when PV input diminishes so added battery capacity may be needed.

Personally I operate two systems, each capable of supporting a 9000 BTU A/C unit during the day, but I found it to be a loosing battle against the sun, so I only use it after sunset to take the edge off and remove humidity, 30°C (86°F) is comfortable enough for me indoors, which is significantly lower than outside. My sleeping temperature is 28°C (82F) for this my Diakin unit runs overnight mostly at 150W cycling, or off after midnight if the sky is clear.

When living in the tropics it's best to become acclimatized because it's hot all year, many foreigners end up becoming mall rats to escape the heat, I live in the country on a farm spending most of my time outdoors working.

@TC McClure What battery capacity / nominal voltage and array capacity do you have ?
McGivor: Thanks for the info and sorry for the delay. I've been addressing windmill pumping issues and I am not a good multi-tasker.
I have a 24V-1125 AH system. My array produces 1300-1500W most of the day as I'm in inland Southern California. The panels are mounted on 2 Zomeworks trackers so I get maximum output very early. I Produce 120VAC with a Trace 4024.
 

carolinabigfoot

New Member
Joined
Sep 8, 2021
Messages
60
Location
Northwestern NC
I painted the walls and the roof of my trailer with white polymer paint and built a porch cover on the south side. Hugh difference! Plus white window curtains. The temps got pushed down 7 - 10 F and the trailer heats up a lot slower.
 
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