Who has first hand knowledge of a 120v mini split watt hours in a 24 hour day
- Thread starter Rocknemo
- Start date
There are a lot of variables. Set temp, outside ambient temp, how well the structure is insulated, sun exposure, other heat sources within the structure, etc. The exact same unit may use 2x as much power for one person than another.
One way to get an idea about your usage is to buy a Midea or other brand inverter window AC and measure usage of that. If you like the results, sell the window AC and replace with a mini-split. https://ashp.neep.org/#!/ has COP ratings. SEER is gamed by the manufacturers.
RCinFLA
Solar Wizard
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- Jun 21, 2020
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- 3,565
Beside actual climate conditions, there is an additional electrical factor that are common to 120vac mini-splits.
Most recognize the importance of power consumption on battery powered AC inverter supply. Other important factor is many of 120vac mini-split three phase variable compressor speed inverter units do not include power factor correction for their AC input. This increases the peak current load on battery powered AC source inverters resulting in lower efficiency performance on battery powered AC inverter. The extra losses in battery powered AC inverter is caused by 120vac mini-split air conditioner but not included in the report of mini-split power consumption.
Without the AC to HV DC power factor correction circuit, the AC input power factor will be 0.60-0.65 with short high current spikes in the AC input current profile due to the simple rectifier-filter AC to HV DC supply for three phase inverter DC input supply. This is what I have on my expensive Samsung variable speed compressor refrigerator that runs on 120vac input.
It would be very helpful information if folks report their 120vac mini-split model and measure its power factor at maximum load. A Kill-A-Watt meter or one of the low cost $20 energy monitors with CT current sensors that include PF reading can be used. If you want to run a mini-split A/C from battery power, it is better to avoid models with poor power factor.
120 vac air conditioners are primarily a U.S. market appliance and because most areas in U.S. do not regulate power factor performance for residential appliances, manufactures cut their costs by eliminating the extra circuitry for PF correction. Europe has regulations on residential appliance PF and this results in 230vac mini-split A/C bought in U.S. are more likely to be similar guts to European supplied units with good power factor performance.
Most recognize the importance of power consumption on battery powered AC inverter supply. Other important factor is many of 120vac mini-split three phase variable compressor speed inverter units do not include power factor correction for their AC input. This increases the peak current load on battery powered AC source inverters resulting in lower efficiency performance on battery powered AC inverter. The extra losses in battery powered AC inverter is caused by 120vac mini-split air conditioner but not included in the report of mini-split power consumption.
Without the AC to HV DC power factor correction circuit, the AC input power factor will be 0.60-0.65 with short high current spikes in the AC input current profile due to the simple rectifier-filter AC to HV DC supply for three phase inverter DC input supply. This is what I have on my expensive Samsung variable speed compressor refrigerator that runs on 120vac input.
It would be very helpful information if folks report their 120vac mini-split model and measure its power factor at maximum load. A Kill-A-Watt meter or one of the low cost $20 energy monitors with CT current sensors that include PF reading can be used. If you want to run a mini-split A/C from battery power, it is better to avoid models with poor power factor.
120 vac air conditioners are primarily a U.S. market appliance and because most areas in U.S. do not regulate power factor performance for residential appliances, manufactures cut their costs by eliminating the extra circuitry for PF correction. Europe has regulations on residential appliance PF and this results in 230vac mini-split A/C bought in U.S. are more likely to be similar guts to European supplied units with good power factor performance.
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RV10flyer
Solar Wizard
- Joined
- Mar 8, 2021
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My Fujitsu 9000 btu 33 SEER mini hp pulls 3.7A max at 240V in cool mode and 7.0A in heat. My total kWh per day is around 6.0, but that depends on too many factors. I would recommend getting the highest SEER rated unit that you can afford.
26 SEER 120v here:
hvacdirect.com
9,000 BTU 26 SEER Wall Mount Gree Mini-Split Vireo Gen 3 Single Zone Heat Pump - 3VIR09HP115V1A
The Vireo+ combines cutting edge technology and a minimalist design. It has been designed to blend into any living space, with a slim cabinet that can be installed onto the wall. The wall mounted unit has an easy-to-read display which gives information about the operating mode. With four speeds...
hvacdirect.com
I completely agree! My 240V Fujitsu 12k MS uses very little for AC (2-3 kw/day?) for my application, but uses a lot more for heating. A friend has the same model and his consumption is at least 2-3 times as much. There's so many variables.
I have 2, one is a GREE which pulls pretty well 11 amps or 31680 watts in a 24 hour period. This unit does have a compressor. The second unit is a Prime, this is an inverter unit, no compressor. It also pulls appx 11 amps to start but in a 24 hour period uses appx 14400 watts in a 24 hour period. This is literally running 24 hours per day in this hot 100+ degree temps. Both are 110 units.
Ampster
Renewable Energy Hobbyist
Thanks for pointing that out. What little I know of A/C and refrigeration is that it is fundamentally a cycle of compression and expansion.
Temperature differental is huge factor. Out here in Vegas, keeping my shop 75F when it is 120F outside can prove difficult.
If you seal any drafts and have a nicely insulated building, should be easy to do.
And it's hard to calculate. Need to run it and measure total consumption over time.
If you seal any drafts and have a nicely insulated building, should be easy to do.
And it's hard to calculate. Need to run it and measure total consumption over time.
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It is SOOOO much more than just temperature also. There is a huge array of issues to calculate design load on a structure.
Orientation, overhang, roof color, construction material, infiltration level, insulation factor, ambient design temp, humidity levels, desired temp, occupant qty. there are more as well.
Several websites offer load calculation worksheets.
Orientation, overhang, roof color, construction material, infiltration level, insulation factor, ambient design temp, humidity levels, desired temp, occupant qty. there are more as well.
Several websites offer load calculation worksheets.
OffGridInTheCity
Solar Wizard
I run a 9000 BTU Senville in my 7 x 14 cargo trailer with 1" (R5) insulation all around (floor, ceiling, walls, nooks/crannies) and no windows.
It uses 5-7kwh/24hrs for mid temps - 40F low 90F hi ambient - to maintain 75F inside.
At 25F low ambient or 100+F ambient, to keep 75F inside, power is in the 15kwh range.
At 25F low ambient to keep 60F inside, power was back down to 5-7kwh.
As said above, there are sooo many variables. INSULATION is a key factor, R5 is not that good, and the whole 'silver/radiant/reflect thing' didn't seem to do anything.
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jmjack
Need More Sun
I have a MrCool 12K 120V minisplit that averages around 800 watts. If it working hard, 1000 watts, somewhat idling maintaining room temperature it has been as low as 400 watts. I live in a small 1100 sq/ft house with 1 bedroom/bathroom upstairs. A Mini splits is installed in the upstairs and downstairs. It has been 100+ the last week and I still only need to run the upstairs unit (i can pull air from upstairs to downstairs). Downstairs fluctuates from 73 in the morning to 78 in the evening. I attribute the insulation as the main factor here. Underroof is spray foamed, under the house is spray foamed, inside walls is standard rockwool insulation but outside walls are covered in 3/4 thick of polyiso-insulation. Then add the tree cover! So your mileage will probable vary but I feel the mini-splits are the way to go for lower energy consumption vs a window or central unit.
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So I assume your unit is running full time and not cycling off as its basically pulling on avg 6.6 amps. Thanks for your input, mine will be used to supplement our main ac and will be run off solar. I'm just trying to get some real time numbers knowing everyones conditions are different.
jmjack
Need More Sun
Yes, its running full time, I set it on 68 and let it run. The only time its off is during filter cleanings or I had the power off a few times the past couple months for other electrical changes/upgrades. The only time I run the downstairs minisplit is when we run a freeze dryer in the utility room, that heats up the room quickly!
You must have not seen post number four in this thread. 120V mini split on inverter may be false economy.
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