HI Dave Interesting that you bring that up, as far as I can tell, Energy Star rated DIY units are only up to about 24kBTU, I don’t know why.
Another piece of data I can’t find is actual efficiency curves. Which would be based on outside and inside temps. I wonder if anyone has info as to those two things Thanks for all the input, very helpful jay > On Mar 14, 2025, at 2:07 PM, Dave Angelini Offgrid Solar via RE-wrenches > <[email protected]> wrote: > > It would depend on the size of the split 😉 It would also depend on the SEER > rating and the climate you are in. I try to only use the best model in the > brand for Offgrid. It cost more for a reason and can run longer into the > evening before using the battery. The smaller 33 SEER units work well as you > can keep a medium house cool before it ever warms up. Also can easily run on > a 400AH battery all night with a reserve. They sip the power and as long as > the maintenance is done, can last a long time. > > For instance, the Fujitsu 9000 btu. > > <e7291169.jpeg> > > Dave Angelini Offgrid Solar > "we go where powerlines don't" > <http://members.sti.net/offgridsolar/>https://offgridsolar1.com/ > <http://members.sti.net/offgridsolar/> > e-mail [email protected] <mailto:[email protected]> > text 209 813 0060 > > > On 2025-03-13 3:03 pm, Kristopher Schmid via RE-wrenches wrote: > >> Hi All, >> >> Since we are on the topic, does anyone have a good method for predicting the >> kwh consumption of a mini-split? >> >> Thanks, >> Kris >> >> >> Shine On! >> >> Kris Schmid >> Legacy Solar, LLC >> 137 West 1st Avenue >> Luck, WI 54853 >> www.legacysolar.com <http://www.legacysolar.com/> >> 715-653-4295 >> NABCEP Certified PV Installation Professional >> Licensed Wisconsin Master Electrician >> BSEE >> >> >> On Thu, Mar 13, 2025 at 3:58 PM Jason Szumlanski via RE-wrenches >> <[email protected] >> <mailto:[email protected]>> wrote: >> Most off-grid homes here in Southwest Florida, one of the most challenging >> air conditioning places in the country due to heat and humidity, have moved >> to mini-splits. I have a client's system with quad Sol-Ark 15K that is >> running eight separate mini-splits and a 4-ton central air unit at a >> sprawling residential complex. There are no issues to report. These were all >> installed by a reputable local HVAC contractor, so they are not likely DIY >> brands. I am not certain about the tonnage, but I believe each mini-split is >> 1.5 tons. These are in a highly corrosive/salt environment. I can't imagine >> they will last more than a few years each. But from what I hear, clients on >> the islands are treating them as disposable in a way. It's still much >> cheaper than replacing central air units every few years. >> >> I have another client's system with a single Sol-Ark 15K and it has two >> 2-ton mini-splits that are DIY by the homeowner. They barely dent the >> batteries each day. I see them using as little as 400W to maintain temp in >> high ambient heat. Most other clients have single mini-splits. I concur with >> one of the earlier comments to stay away from multi-zone if possible. I >> don't think there are considerable cost savings anyway, and I have not been >> able to detect any energy savings going that route. >> >> There is a guy I did some work for who is running a few old school window >> shakers on a Sol-Ark 12K and he has constant problems with surges and >> performance of the units. He is in line for a mini-split soon, and plans to >> DIY. >> >> Personally, I have a 2-ton DIY cooling my uninsulated garage at home (on >> grid) when I need to use it for short periods in the summer. It works like a >> champ, and it was dead easy to install. The hardest part was getting the >> line set out through the block wall. I think I paid $1,200 for it, including >> the trim kit to hide the line set and a wall bracket for the compressor unit. >> >> I think the bottom line for me is super low startup surge and then fairly >> consistent power draw once desired temperature is reached. I feel this is >> much easier to plan for off-grid rather than repeated start/stop cycles. >> >> Jason Szumlanski >> Principal Solar Designer | Florida Solar Design Group >> NABCEP Certified Solar Professional (PVIP) >> Florida State Certified Solar Contractor CVC56956 >> Florida Certified Electrical Contractor EC13013208 >> >> On Thu, Mar 13, 2025 at 4:41 PM Wayne Irwin via RE-wrenches >> <[email protected] >> <mailto:[email protected]>> wrote: >> Hi Pieter, >> >> I should have said that I "No Longer" vacuum them as the extra step that I >> previously applied made no difference in my experience. We are also in FL. >> with extremely high humidity which might be the difference. Most of the AC >> contractors here confirm the same experience. >> >> That said, they do work well with solar applications. >> >> >> Wayne Irwin >> President >> License #CVC56695 >> State Licensed Solar Contractor >> Pure Energy Solar International Inc. >> [email protected] >> PureEnergySolar.com <http://pureenergysolar.com/> >> SolarChargingStation.com <http://solarchargingstation.com/> >> 352 377-6527 Office >> 352 336-3299 Fax >> >> >> The Sun Is Always Shining! >> >> The content of this message is Pure Energy Solar Confidential. If you are >> not the intended recipient and have received this message in error, any use >> or distribution is prohibited. Please notify me immediately by reply e-mail >> and delete this message from your computer system. Thank you. >> From: pieter offgridenterprises.org <http://offgridenterprises.org/> >> <[email protected] <mailto:[email protected]>> >> Sent: Thursday, March 13, 2025 4:09 PM >> To: RE-wrenches <[email protected] >> <mailto:[email protected]>> >> Cc: Wayne Irwin <[email protected] >> <mailto:[email protected]>> >> Subject: Re: [RE-wrenches] mini splits >> >> Wayne, I saw your post regarding the use of ductless mini splits. I too use >> them extensively, and have an unblemished track record using them. I must >> say that your failures may be in part due to the fact that you do not >> evacuate the system during the installation process. For what it is worth >> the proper procedure is to precharge the system with nitrogen to about >> 200PSI. Then check for leaks and verify the system will hold pressure. Then >> pull a vacuum on the system for maybe 15 or 20 minutes before releasing the >> refrigerant. If you skip these steps you are vulnerbale to diminished >> performance caused by any air left in the circuit, any moisture will react >> with the refrigerant and turn acidic eventually leading to corrosion. I see >> you keep the lines closed as much as possible but non the less I think will >> find your system longevity will increase, and potentially the performance >> will be better. >> You are getting about ten years so not to bad but I have some healthy >> systems that are 20 years old still going strong. >> Pieter >> From: RE-wrenches <[email protected] >> <mailto:[email protected]>> on behalf of Wayne Irwin >> via RE-wrenches <[email protected] >> <mailto:[email protected]>> >> Sent: Thursday, March 13, 2025 12:02 PM >> To: RE-wrenches <[email protected] >> <mailto:[email protected]>> >> Cc: Wayne Irwin <[email protected] >> <mailto:[email protected]>> >> Subject: Re: [RE-wrenches] mini splits >> >> Hey Jay, >> >> I live off grid (25yrs) in North Fla. (temp range is teens - 100+ F) with >> mini-splits throughout the house (2,700sq'). >> I have used just about every brand. We primarily use them for cooling but >> also use heat to supplement the wood stove. >> I can't imagine living without them. Although it's a love/hate relationship. >> My experience is that you get about 10 years max from whatever brand you >> buy. Typically, the inside unit corrodes from condensation and leaks out, or >> the outside unit reversing valve locks up in cold or heat position. IMO They >> are not worth repairing. We currently have 4 - 1 Ton units and 1 - 2 ton. I >> only buy 1 to1 systems vs 1 -4 as it offers redundancy. I initially tried >> "reputable" brands which typically cost more but have since migrated to >> whatever is the cheapest. >> That said I like Gree and/or the knock off brand that they make (good for >> the price and holding up well). When I am in need of more than one, I always >> buy an extra to swap out whichever unit dies first. >> Fortunately for me, years ago, I had a buddy show me how to install them. >> Pretty simple. They come pre-charged and can typically handle up to 30' of >> line with no issues. If possible, find someone to show you once. YouTube >> will offer many WRONG ways to do it videos. >> I don't use the vacuum on the lines. I just keep the lines plugged and dry >> until I hook them up. >> >> My 15kW array with 2 - VFX3648R's has had no issue powering any of them. >> >> I hope this info helps. >> >> Wayne Irwin >> President >> License #CVC56695 >> State Licensed Solar Contractor >> Pure Energy Solar International Inc. >> [email protected] >> PureEnergySolar.com <http://pureenergysolar.com/> >> SolarChargingStation.com <http://solarchargingstation.com/> >> 352 377-6527 Office >> 352 336-3299 Fax >> 352 316-1637 Cell >> >> The Sun Is Always Shining! >> >> The content of this message is Pure Energy Solar Confidential. If you are >> not the intended recipient and have received this message in error, any use >> or distribution is prohibited. Please notify me immediately by reply e-mail >> and delete this message from your computer system. Thank you. >> From: RE-wrenches <[email protected] >> <mailto:[email protected]>> on behalf of Michael >> Morningstar via RE-wrenches <[email protected] >> <mailto:[email protected]>> >> Sent: Thursday, March 13, 2025 11:05 AM >> To: RE-wrenches <[email protected] >> <mailto:[email protected]>> >> Cc: Michael Morningstar <[email protected] >> <mailto:[email protected]>> >> Subject: Re: [RE-wrenches] mini splits >> >> I'm interested in this too >> >> On Thu, Mar 13, 2025 at 7:39 AM jay via RE-wrenches >> <[email protected] >> <mailto:[email protected]>> wrote: >> HI All, >> >> I have been getting a lot of questions about people wanting to install mini >> splits in their off grid homes, and in normal homes. >> >> The line of questions usually involves DIY vs contractor. Of course the >> price difference is staggering, roughly 5X more for contractor. And I'm >> being asked all sorts of questions about the DIY versions. >> >> Is there a good place for information so I can educate myself as to the >> different brands etc >> Or maybe someone can contact me off list if they have some info to share. >> >> Thanks' >> >> jay >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> Pay optional member dues here: http://re-wrenches.org >> <http://re-wrenches.org/> >> >> List Address: [email protected] >> <mailto:[email protected]> >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> There are two list archives for searching. 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