diy solar

diy solar

Mini Split A/C Power Consumption?

I have a 12000 Fujitsu 29 SEER and a 1000sf with R-50 attic, R-17 walls minimal number of double pane. On nights with 32 low and approximately 50 for high with unit set to 73 deg and the fan set to med. high. ( fan set med high to push down hall to rest or the house). There is about 2 deg difference in temperature from one end to the other. It uses 8 kw in the 24 hours. On nights in the 20s I use a pellet stove. On nights in the 1s I use both.
 
I have a 12000 Fujitsu 29 SEER and a 1000sf with R-50 attic, R-17 walls minimal number of double pane. On nights with 32 low and approximately 50 for high with unit set to 73 deg and the fan set to med. high. ( fan set med high to push down hall to rest or the house). There is about 2 deg difference in temperature from one end to the other. It uses 8 kw in the 24 hours. On nights in the 20s I use a pellet stove. On nights in the 1s I use both.
Thank you! Between yours and @Ampster's numbers is giving me confidence that a 10kWh battery will get me in the over night game! :)
 
I know everyone already knows this, but air sealing the space and properly insulating it will dramatically reduce the energy usage. As will white roofs, blinds and curtains over the windows, etc…
 
For clarity I use an additional 7 kw for the household in the same 24 hours. Fridge, freezer, we’ll, and other.
That's how I understood you're answer to my specific question. I'll be calculating each of those as well prior to ordering my batteries. :)
I know everyone already knows this, but air sealing the space and properly insulating it will dramatically reduce the energy usage. As will white roofs, blinds and curtains over the windows, etc…
I've been hitting it pretty hard from that direction for the last couple of years and have seen really remarkable results. Who knew even insulation in a pup-tent helps? ;)
 
Why guess when you can actually pull the specs and see what it does at various outdoor temps? Here's part of the the answer: https://mrcool.com/wp-content/dox_repo/mc-diy-es-ss-en-01.pdf

The spot I circled in red shows that when it's 32F outside and 65F inside the 12,000 BTU nominal rated unit uses 930 watts (input) and has a total capacity (TC) of 9,390 BTU's.

View attachment 87106
That link has the same chart for cooling.

The other part of the answer is that you are going to have to take your best guess at how many hours per day it's going to run at what temp. A good starting point to take some notes about how long your current unit runs at particular temps. That combined with the BTU rating of your current unit will get in you in the range. It's not going to be an exact number but you'll be in the ballpark.
Thanks, I like it when someone else does most the research for me!
 
I think OP asked his question specifically "how much do they consume per hr" meaning if its on and running what does it consume. Everyone can then calculate how much power they need based on their location/temp/structure etc. But the base line of if its on and running then its consumeing XXXX should be the datapoint we are looking for.
This is available in the "submittal" sheets that each manufacturer must provide. A search should turn up the submittals for each brand and unit. For example ......... https://www.fujitsugeneral.com/us/support/downloads/halcyon/submittal-sheets.html
 
I got 8 Mitsubishi Zen series minisplit units in different rooms and f.ex. my office only draws 300w when running with cooling. South Spain. Also, this series is very silent when running. No noise whatsoever. Highly recommended.
 
I got 8 Mitsubishi Zen series minisplit units in different rooms and f.ex. my office only draws 300w when running with cooling. South Spain. Also, this series is very silent when running. No noise whatsoever. Highly recommended.
Are those 230 only? Not seeing any for North America.
 
I like where this thread has gone as far as the comedy aspect, but really if you just want to know ballpark what something uses when it's "on.." just multiply input voltage X rated amps on the dang sticker X 24 hours in a day and you will get your unrealistic worst case scenario number where you live at the equator but earth also stopped spinning at noon local time for some reason and now you have to run the compressor all 24 hours of the day and wear sunglasses in bed.

But I would say reality is that YES you are certainly going to be able to cool a useful amount of space overnight on a 10kwh battery. I cool my <150sqft bedroom and run my fridge and random tiny appliances on standby around the house on <4kwh overnight.
 
I think Iwill wait till the new Energy Bill goes into effect before investing in a mini split. There maybe rebates of $2k or more and big tax write offs. Two years ago, I bought a $1600 tankless water heater and got $1500 back in a pge rebate and I installed it myself, which saved 2 to3k for a plumber.
 
Kinda sad that i can identify 'california numbers' and then look over at the poster's location and go.. yup.

I'm guessing you are talking about investing in a large multi-zone mini split because many single zone units are less than 2k to begin with.
 
I think Iwill wait till the new Energy Bill goes into effect before investing in a mini split.
The House is set to vote on it today or tomorrow and it is about as sure as sure gets that it will pass and be signed by Biden. Even if you did it today it would still qualify for the credits. But summer is just about over in Paso Robles so take yer time ...you'll have til 2032. ;)
 
The House is set to vote on it today or tomorrow and it is about as sure as sure gets that it will pass and be signed by Biden. Even if you did it today it would still qualify for the credits. But summer is just about over in Paso Robles so take yer time ...you'll have til 2032. ;)
I need something that will run off solar and batteries for the winter. My electric is higher in the winter than the summer because my tenants run 1500 watt electric heaters. In summer, there are five 500 wat window AC's. I just got three of them switched over to my new solar system and my electric bill dropped over $100. last month.
 
I am looking at replacing my (very) old central a/c package unit this year and the mini split units seem a very attractive alternative at this point and I believe I'll save quite a bit on my power usage since I won't be cooling or heating areas I'm not using. I'm thinking three 9k btu units will probably be adequate for my needs. My question is, has anyone here ever put a watt hour meter on a 9k or 12k btu unit to see how much power is required on an hourly basis? I need to factor that into my calculations when I size my battery bank initially, so it will carry me through until generation begins again each morning.
Thanks.
That is the problem with heaters, you mostly need them when the sun is down and the days are short. I just added a second EG4 48v 100AH battery. I'm hoping two will be enough to run my central heater fan plus another 250 misc. watts/hr. Luckily it is wired to 120v and the gas combustionchamber is or at least was 98% efficient. it is ten years old now.
 
That is the problem with heaters, you mostly need them when the sun is down and the days are short. I just added a second EG4 48v 100AH battery. I'm hoping two will be enough to run my central heater fan plus another 250 misc. watts/hr. Luckily it is wired to 120v and the gas combustionchamber is or at least was 98% efficient. it is ten years old now.
So I made that comment back in March. I ended up installing 2-12k btu MrCool mini splits and have pretty much been through the worst heat wave we've seen around here in 10 years. I was able to keep my 1100sqft. shack at 74º throughout using just those 2 units. I've been able since to calculate the difference between running one unit vs. running 2 units is about 60 cents a day. I'm paying 10 cents a kWh from the grid. Running just 1 unit it seems to be adding about $1.25 per day to my metered usage. I'm completely sold on heat pump tech for use in air conditioning.
My shack is 100% electric with the exception of my gas grill which we use 3-4 times a week. I'm calculating I'll need 15-17kWh of battery storage to get me from last usable light to first usable liight daily so my starter battery will need to be 4 of those EG4 48v 100ah setups.
I'm still arguing with myself on the all-in-one to buy. Right now I'm leaning toward that Growatt 12kW split phase inverter, but could probably be talked into something else. It would be large enough to run my entire shack and shop.
I'm calculating I will only need an additional 3.5 kW in solar to cover 100% of my usage. That will be the last addition to my hybrid setup.
 
I need something that will run off solar and batteries for the winter. My electric is higher in the winter than the summer because my tenants run 1500 watt electric heaters. In summer, there are five 500 wat window AC's. I just got three of them switched over to my new solar system and my electric bill dropped over $100. last month.
Be prepared for renters to keep using the plug in heaters even with the minis running… my experience is they run them because they like to be hot… I’ve been to emergency heat out calls where the house was 99 degrees, and they called because they couldn’t get it HOTTER… I adjusted the thermostat to SHOW a higher temp…
 
With today's energy prices, nothing is lower cost to operate in the lower 48 states than modern inverter based heat-pumps. In the last year, I replace a fully functional 4 ton york with the MrCool ducted mini split primarily as it was 13 years old and even with a soft start kit the LRA was just to high for my Solis 5G.

Even with paying an AC company in gold bars for the installation, cost was 5K with my purchasing all the parts myself. I did replace the cheap PSC motor in the Air handler in the ducted system with a ECM unit and controller for $500 in parts, best thing one can ever do as the airspeed can be precision dialed in for comfort and has programmable second speed by time. Since the outside unit is variable, it auto adjusts when the air handler increases flow in the second speed, but rarely even does that as the system loaf's along even in 95 degree humid conditions.

Since then I have so much spare energy from solar, I have installed myself a pair of 9K 18 Seer Mr Cools and now my Garage and Porch are 4 season spaces, total cost for that was about $1600 for two units and all installation tools and materials ( think mounts, line covers, breakers, disconnects, wiring, code required GFCI service outlets by the condenser).

Even with all this, I'm net positive (selling) 2.4MW to the utility so far this year after covering 100% of the eclectic for the home.
 
I have noticed a high SEER with one head units. The SEER drops considerably with a two head unit, but the heat pump appears to be the same. If I just use one head of a two head unit, should the SEER be the same as a dedicated one head unit?

Reason I ask is I’d like to put one head downstairs for heating and use the upstairs one for cooling (not at the same time. Winter/Summer)
 
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