Where are the mini splits????

[Q-Dog]

I don't have a dog in the fight of this debate, but this comment caught my eye. With respect, that's YOUR goal, but may not be the primary goal of others. I installed a system last year that may never pay for itself. But it was a lot of fun, and I learned a lot. We're installing a system in a new house we're building that may be in the same boat. But it should give me the option of one day simply turning off the grid connection if I choose to do so, and that's worth something to me. I often do things that don't generate a positive economic return, but they give me freedom, peace of mind, and enjoyment.

OK, resume normal programming. Tiny rant over.

Exactly. I built my system to keep stuff cold and keep some lights on when the grid goes down. It will never "pay for itself" in actual dollars. But, it felt like it paid for itself during our last overnight power outage when we were able to watch TV and otherwise go about our evening without having to start up a gas generator.

We have cheap power. I think adding some solar powered air conditioning would be perfect for our situation. We could have some heating/cooling without having to expand our existing solar and battery backup.

 

[automatikdonn]

Just get a Pioneer....no need to connect it directly to solar panels. Works great for me. Cheap to boot.

I converted 3 central HVAC units at my place to pioneer mini splits. Working great, headed into my second winter with them and they survived the 4th and 5th hottest years on record in North Texas! No complaints.

 

[summit]

I converted 3 central HVAC units at my place to pioneer mini splits. Working great, headed into my second winter with them and they survived the 4th and 5th hottest years on record in North Texas! No complaints.

it took a while to narrow down to the Pioneer: an US company, 30% tax rebate qualification, and sufficiently low current demand for battery backed operation. Installed a Pioneer Ultra Diamond last month and the system looks quite decent. Planning to install 3 more in coming months, the main application is for distributed winter heat. These are spec'd to work down to -13F. Pioneer had a bad history of leaking freon at the flaring, so I was prepared to re-flare. But close inspections looked quite decent.

 

[jfharper]

I installed a 12K EG4 hybrid this summer, works great. For us, when the weather cooled down, we don't turn in on. I'm leaning with Zwy on this...there are many days I look at the those four 290w panels just sitting there when they could be charging batteries. I think I saw 850w pulling from the split at times...that's 850w or greater can translate into 2-3Kw batt charge per day for something else in the house. I'm glad to read the different opinions on this thread, tho...keep 'em coming

 

[Madcodger]

Some people say that but if it cost you 10 times the cost of grid power, would you still install a system?

Well, I'd say you are a bit worked up. Easy, big fella. I actually agree that in most cases, "solar" mini splits aren't as beneficial as just installing a mini-split and having a solar system that can power "whatever". But that may not be what others want. So, who cares? If they want to power it by hooking it up to a bicycle and pedaling, let 'em! I'm just saying that people do all sorts of things "just because", and if it doesn't harm others, let 'em do it. It's not like there's a worldwide shortage of mini splits so they need to be rationed.

I could have simply run an electric line from the garage to the building where I instead installed solar and called it a day, for about 1/10 what I actually spent. In fact, I later did exactly that, just so I wouldn't have to fire up a generator after a cloudy stretch in winter. I have friends who call that a huge waste of money. Others want to do the same thing I did, just because they can. So while I don't have some formula developed for where I draw the line, I guess in this case I was willing to spend 10x just for the fun and learning. I can get my road plowed all season for about $1000, but I have about $100K in a tractor, implements, and tractor shed to do it myself. So, again, that doesn't make much economic sense, but it sure gives me more freedom to get out and go places when I want to do so. People spend money in ways others think is foolish, all the time. Let 'em. It's a free country.

 

[Zwy]

Well, I'd say you are a bit worked up. Easy, big fella.

I can assure you I'm not worked up. I'm presenting my thoughts on this subject from the other side of the discussion. Some may not like my opinion after spending the money, it might just be the "next cool thing" isn't quite so cool after the shine wore off.

I actually agree that in most cases, "solar" mini splits aren't as beneficial as just installing a mini-split and having a solar system that can power "whatever". But that may not be what others want. So, who cares? If they want to power it by hooking it up to a bicycle and pedaling, let 'em! I'm just saying that people do all sorts of things "just because", and if it doesn't harm others, let 'em do it. It's not like there's a worldwide shortage of mini splits so they need to be rationed.

Easy there big fella.

I've seen these threads on the PV powered mini splits and the resulting cheerleading that occurs from others thinking it might be the best thing since sliced bread was invented. It's because they spent the money and need in their mind to justify their decision. I'm presenting an opposing viewpoint, some like yourself may not want to hear it. Various people read these threads, I think they are entitled to see dissenting thoughts on the subject, good or bad. It may help them make an informed decision.

I could have simply run an electric line from the garage to the building where I instead installed solar and called it a day, for about 1/10 what I actually spent.

What if was 20X?

In fact, I later did exactly that, just so I wouldn't have to fire up a generator after a cloudy stretch in winter. I have friends who call that a huge waste of money. Others want to do the same thing I did, just because they can. So while I don't have some formula developed for where I draw the line, I guess in this case I was willing to spend 10x just for the fun and learning.

So there is a limit?

I can get my road plowed all season for about $1000, but I have about $100K in a tractor, implements, and tractor shed to do it myself. So, again, that doesn't make much economic sense, but it sure gives me more freedom to get out and go places when I want to do so. People spend money in ways others think is foolish, all the time. Let 'em.

Install PV powered mini splits every 10 feet along the driveway and just melt the snow away instead.

It's a free country.

That is correct and I am allowed to present my thoughts on the subject instead of people trying to keep me from commenting.

 

[Plum Crazy Rob]

It works for ME - YMMV . I'm saving nearly a $1000 a year at 0.13 kwh, 4 yr payback. Seems pretty justifiable to me
I don't understand the problem, outside slightly underused solar panels at 0.30 / W new. Solar panels are not the cost limiting factor anymore - just let that GO. Inverters and Batteries ARE.

I feel like large AIO inverters are where 20 yrs ago when 65" LCD TVs came out and were $5k. Will we be able in 5 yrs to go to Walmart and buy a Dewalt or TCL brand 15kW inverter for $800?? Probably NOT, impossible to see especially where DIY Solar is going. Let's hope??

 

[Nobodybusiness]

I like the idea of the "not having to pull a vacuum line set" I've done some research and have not found any other brand other than the MR Cool 4th gen and the EG4 brand. But if there would be a problem I'd probably have better result with service with Mr Cool. I'd been using a Pioneer now for 5 yrs, been great, looking for another but with the quick connect lines.

The thing I have seen is you have to be careful with the MR Cool universals not the mini splits but universals.

When they sweat in those King valves, they cook them and they leak.

Had to replace King valves in my Airhandler so went ahead and replaced the outside unit valves while I had it down.

 

[cs1234]

It works for ME - YMMV . I'm saving nearly a $1000 a year at 0.13 kwh, 4 yr payback. Seems pretty justifiable to me
I don't understand the problem, outside slightly underused solar panels at 0.30 / W new. Solar panels are not the cost limiting factor anymore - just let that GO. Inverters and Batteries ARE.

Legally installed to code and permitted, solar panels are a huge limiting factor. The "approved" racking, wiring/conduit, disconnect costs for roof / ground mounted solar panels is simply insane. Just because they are connected to an HVAC doesn't make them immune from the nonsense.

If you don't need/have to deal with that stuff, yes, solar panels are pretty cheap.. load up!

 

[justgary]

I don't see having panels sit idle thru a year as cost effective.

What do your panels do when your batteries are full? No matter what you use solar for, eventually the load will be satisfied and the panels will sit idle. Are you concerned about the corn field sitting idle after harvest? Think of all that wasted solar energy just heating the ground. Seasonal use of the corn field seems quite acceptable.

Come to Florida in the summer if you want to see a good use case for direct solar air conditioning. The sunny days are the hottest days, and the solar load on the roof and south walls means that a building will heat up quickly no matter how much insulation it has. I have a three ton water exchange unit that runs a lot during August. I am considering installing one or two solar direct mini splits just to lower the power bill during the summer.

It will be a lot cheaper and simpler than adding batteries and inverters and tying into my existing panel. Set the mini splits to a few degrees cooler than the main unit and let them run when they can. Batteries and and inverter could easily add at least $10,000 to the cost of the installation.

If the power company gets nosy and wonders why my usage is so low during the summer, they can't complain if I don't have an inverter tied to my grid panel.

 

[Zwy]

What do your panels do when your batteries are full? No matter what you use solar for, eventually the load will be satisfied and the panels will sit idle. Are you concerned about the corn field sitting idle after harvest? Think of all that wasted solar energy just heating the ground. Seasonal use of the corn field seems quite acceptable.

I'm always looking at moving more loads to electric. I want to use as much generation capability as possible.

Come to Florida in the summer if you want to see a good use case for direct solar air conditioning. The sunny days are the hottest days, and the solar load on the roof and south walls means that a building will heat up quickly no matter how much insulation it has. I have a three ton water exchange unit that runs a lot during August. I am considering installing one or two solar direct mini splits just to lower the power bill during the summer.

How will you run the mini splits in the evening/night? Around here, the evening is when the dewpoint gets quite high and it is sticky.

It will be a lot cheaper and simpler than adding batteries and inverters and tying into my existing panel. Set the mini splits to a few degrees cooler than the main unit and let them run when they can. Batteries and and inverter could easily add at least $10,000 to the cost of the installation.

If the power company gets nosy and wonders why my usage is so low during the summer, they can't complain if I don't have an inverter tied to my grid panel.

 

[42OhmsPA]

I'm always looking at moving more loads to electric. I want to use as much generation capability as possible.

This! When I'm home on the weekends I fight the system to keep the batteries from hitting float. I don't think I would have ever bought a water distiller or 'portable sauna' if I were on the grid. It drives me nuts wasting all that potential energy... Really need to make up my mind on what EV I want...

How will you run the mini splits in the evening/night? Around here, the evening is when the dewpoint gets quite high and it is sticky.

That was one of the best parts about running my Pioneer off AC from DC storage... Crank the temp down to low 60s and sleep like a hibernating bear while running the bank down to recharge during the day.

 

[Plum Crazy Rob]

This is true. In a related fact it's news to me if anyone yet has an AHJ permitted Solar mini split instl ??? If you do please share how that went, after my PoCo body cavity search fiasco

Legally installed to code and permitted, solar panels are a huge limiting factor. The "approved" racking, wiring/conduit, disconnect costs for roof / ground mounted solar panels is simply insane. Just because they are connected to an HVAC doesn't make them immune from the nonsense.

If you don't need/have to deal with that stuff, yes, solar panels are pretty cheap.. load up!

 

[cs1234]

This is true. In a related fact it's news to me if anyone yet has an AHJ permitted Solar mini split instl ??? If you do please share how that went, after my PoCo body cavity search fiasco

Somebody on here managed to get one approved. He didn't seek them out for approval, they found him. It wasn't that long ago.. a month or two?

He only got approval from the power company though.. don't know about the building code stuff for the solar panels themselves.

 

[SolarScott]

I'm always looking at moving more loads to electric. I want to use as much generation capability as possible.



How will you run the mini splits in the evening/night? Around here, the evening is when the dewpoint gets quite high and it is sticky.

That is when you run them off the rest of your system....while you are not cooking, washing, drying clothes, watching tv, using the computer.....airconditioner is most of my load at night......

 

[Zwy]

Somebody on here managed to get one approved. He didn't seek them out for approval, they found him. It wasn't that long ago.. a month or two?

He only got approval from the power company though.. don't know about the building code stuff for the solar panels themselves.

That was Plum Crazy Rob himself. https://diysolarforum.com/threads/h...d-mount-panels-need-advice-on-response.66976/

 

[justgary]

I'm always looking at moving more loads to electric. I want to use as much generation capability as possible.

Put some grow lamps on the corn (or a weed plantation).

How will you run the mini splits in the evening/night? Around here, the evening is when the dewpoint gets quite high and it is sticky.

I won't. The main A/C can run at night as needed, and I will still save a bunch of money just by letting it rest during the day.

Dewpoint isn't the direct issue, it is the ratio of dewpoint to air temperature (relative humidity). The dew point probably stays the same all day, but the temperature goes down in the evening, which raises the relative humidity. The dew point won't change much until the temperature gets close, then the water will fall out as dew. At that point, you'll have ~95%+ humidity.

It is *always* hot and sticky here, it seems. The air conditioner's first job is removing water (lowering the dew point), and the second job is lowering the air temp. This time of year is our first reprieve from the heat and humidity; it got down to 60% today!

 

[42OhmsPA]

Do the EG4 minisplits have a dry mode?
The dehumidification in dry mode on my pioneer is incredible compared to normal cool mode.

 

[Zwy]

Put some grow lamps on the corn (or a weed plantation).

I won't. The main A/C can run at night as needed, and I will still save a bunch of money just by letting it rest during the day.

Not my thing I guess, it would bother me I could have captured that excess PV and used it to charge a battery to run the mini split at night. I'd be laying in bed, just thinking about that lost power and not get a lick of sleep.

I once had an upright commercial freezer on the wall opposite my bedroom and the head of the bed was against that wall. I could hear it kick in at night and all I could think about was how much it cost me each time it kicked in. ?

I replaced it with a chest type and sleep very well at night.

Dewpoint isn't the direct issue, it is the ratio of dewpoint to air temperature (relative humidity). The dew point probably stays the same all day, but the temperature goes down in the evening, which raises the relative humidity. The dew point won't change much until the temperature gets close, then the water will fall out as dew. At that point, you'll have ~95%+ humidity.

It is *always* hot and sticky here, it seems. The air conditioner's first job is removing water (lowering the dew point), and the second job is lowering the air temp. This time of year is our first reprieve from the heat and humidity; it got down to 60% today!

It's been hot and humid here all summer and this far into fall. 3 stacked cold fronts coming thru now so it will be cold here finally.

 

[SilverbackMP]

On

I love how this thread has devolved into people just arguing their own points, views, and use-cases, as if those are the onl ones that exist.

TWO things CAN be true at the same time.

The PV Direct thing may be extremely practical in some situations.
The PV Direct thing may be extremely impractical in some situations.

IF you don't have any solar, and want to dip your toes in, PV direct can be an inexpensive way to get in.
IF you already have solar, and it's near it's max.. PV direct can allow you to "expand" without the additional costs of inverters/batteries/SCC's/etc
IF you are offgrid for whatever reason, PV direct can allow you to have some modern conveniences you may not otherwise be able to have.

IF you already have a system and batteries with room for more PV, PV direct may be "wasteful" in that you can use the output even when the pv direct device isn't running.

Did everyone forget the "choose your own adventure" books from middle school? Good lawd! Pick a path, and go.

One more use case…though the DC battery direct units would be a much better fit. Creating climatized areas completely away from the grid or a main offgrid system. This could be a sea container or shed for perishable storage or a small cabin.

I say DC battery units (like some Hotspot units) because one could also hook up DC lighting or a small inverter to the same batteries.

But the EG4 units could also work in a Solar only mode (with enough insulation)…at least for cooling. Probably iffy if you are depending on it for freeze protection. Although freeze protection would be iffy with Hotspot units too depending on region/solar availability and battery capacity.

 

[justgary]

Not my thing I guess, it would bother me I could have captured that excess PV and used it to charge a battery to run the mini split at night. I'd be laying in bed, just thinking about that lost power and not get a lick of sleep.

Ahhhh, this may be the issue. Your assumption is that the panels have lots of excess power going to waste. The direct DC units generally can't tolerate excess panels, so you really don't have any excess. Either you have enough to run the A/C, or you don't. I can sleep at night knowing that the A/C uses all of the power it gets when it gets it, and I didn't waste money on too much power that might keep me awake wondering how to use it.

 

[nc73]

All this split unit talk...going to get another for the garage

 

[Quattrohead]

Come to Florida in the summer if you want to see a good use case for direct solar air conditioning.

I would argue this is actually a rather poor example of their best use, I discovered that Florida is nowhere near as sunny as you might think it is. Every summer afternoon it's either threatening to thunder or it is thundering. And this is when the humidity turns the air into a swimming pool.

 

[Zwy]

Ahhhh, this may be the issue. Your assumption is that the panels have lots of excess power going to waste. The direct DC units generally can't tolerate excess panels, so you really don't have any excess. Either you have enough to run the A/C, or you don't.

There has to be excess, an inverter mini split will draw more wattage at initial cooldown or high temps. When target temp is reached or temperature both inside or outside decreases, the inverter mini split will draw fewer watts as it idles along.

For that reason alone, there has to be enough panels to supply the higher wattage needs and there will be excess PV that will not be used when the unit idles along.

I can sleep at night knowing that the A/C uses all of the power it gets when it gets it, and I didn't waste money on too much power that might keep me awake wondering how to use it.

See above but not only that aspect, but on days when the unit isn't used, those panels could be generating power for some purpose, either charging batteries, powering a household load or charging an EV.

 

[n2aws]

See above but not only that aspect, but on days when the unit isn't used, those panels could be generating power for some purpose, either charging batteries, powering a household load or charging an EV.

Assuming you have batteries that need charged, or household loads that need powered.
As I mentioned previously, there *are* legitimate use-cases for the ac/dc units.

You have your use case, which sounds like this wouldn't be an ideal setup. And thats fine.
However, I gave several scenarios earlier in this thread where it *is* sensible.

These conversations would likely be a lot more productive, if people would just stop assuming that everyone has the same use-case.