DC mini split

[Chicat]

I was looking for input on 24k DC powered mini split systems, most local solar installers are trying to talk me out of it. I only need it to run during the day for A/C we cool off at night so it would not be needed. Does anyone have experience with solar powered mini split system

 

[chrisski]

I was looking for input on 24k DC powered mini split systems, most local solar installers are trying to talk me out of it. I only need it to run during the day for A/C we cool off at night so it would not be needed. Does anyone have experience with solar powered mini split system

Are you asking about DC only?

I am in the Phoenix valley and plan on putting on a hybrid AC/DC EG4 24k BTU in my garage. I’d partially run it on DC with 1k of panels. This can also run on solar only mode.

With that system, no major AC company services it. I think if you went with just a DC unit, you APS be the first on the block with a 24k BTU.

 

[Supervstech]

I see these frequently, and it boggles my mind why anyone would get solar hvac, so the panels do NOTHING when not cooling... seems silly.

 

[billvon]

I was looking for input on 24k DC powered mini split systems

As others have mentioned, either:

1) You dedicate solar panels to that A/C and nothing else, which means you don't get any use out of the panels most of the time.

2) You do a complex thing where you switch the panels between a conventional string inverter system and the A/C. Probably not something you can talk any contractor into.

3) You put in a standard grid tie system and then use it all the time; that offsets your A/C power usage. And under the right conditions will power the A/C 100%.

 

[chrisski]

I see these frequently, and it boggles my mind why anyone would get solar hvac, so the panels do NOTHING when not cooling... seems silly.

You don’t have spare panels left over?

 

[Supervstech]

You don’t have spare panels left over?

If i do, i would use them for production, and feed a regular minisplit...

 

[Bush68]

I have been running an AC/DC mini split in Australia for couple years now and love it.
I have not been connected to the grid for 25+ years and it suits my needs well.
It runs off its own string of panels and yes that’s all they do and I understand that can seem a waste.Thses particular panels were given to me free of charge so didn’t seem to matter.But the thing I like most about the system is it is stand alone and automatically starts and stops.My wife and I both work and it’s great coming home to a cool or warm house because the system has turned itself on as soon as enough Sun hit the panels.And more importantly I don’t need to worry about it running down my batteries if the day turns cloudy while we are not there.
Cheers Rick

 

[dopeassjackson]

If i do, i would use them for production, and feed a regular minisplit...

You would also need a more robust inverter, charge controller and batteries..or turn the system off. At least with the DC system it kind of takes care of its self.

I plan on getting a DC 12kbtu for a offgrid cabin with a solar setup sized for my uses that dont include a mini split. I want it to do it's best keeping the cabin at a medium temp with out my help or input. I only have a 1200w inverter and 330ah 12v battery. Dosnt make sence to rebuild my whole system for such a use.

 

[Plum Crazy Rob]

I'm guessing over 90% on this board, including myself, has unused spare panels - so that is a largely pointless discussion.

Have had a EG4 24k for over 2 yrs and liked it so well, bought 2 12k's for bedrooms and running them over a yr now. So, there is no doubt "they work".

 

[wdwtx2.0]

I see these frequently, and it boggles my mind why anyone would get solar hvac, so the panels do NOTHING when not cooling... seems silly.

I have a whole pallet of 460W bifacial panels just sitting on the ground, still wrapped up, doing absolutely nothing.
I have 4 of the same panels powering a hybrid mini split, conveniently on a rack, if I ever want to use them for anything else.
At least the 4 on the rack are cooling my house. If you have spare ANYTHING, it is doing nothing but sitting there.
I have no problem with that at all.

 

[Koyaanisqatsi]

The thing I don't like about mini-splits running directly from panels is that the need for cooling comes long before the sun is high enough in the sky and lasts long after the sun sets in my area. Seems so much more effective and useful to just rujn those panels to the main system and run the mini-split from the same system. Solves ALL of the problems with panels not getting used or the A/C needed it run when it's not sunny.

I get there are plenty of really good use cases for these systems. But they are a niche that should be used only when required.

 

[HarryN]

Most solar installers want to sell a grid tied system, because that is what they are trained / equipped to do.

A pure DC system for air conditioning will still need to have at least some level of battery pack to be stable, perhaps 3 - 4 hours worth of run time.

The nice thing is that it does not need an inverter to power it the air conditioning compressor and that can be a significant size unit. Most problems in solar systems are going to come from the inverter and grid tie aspect. I have no interest in feeding the grid, so for me that means nothing.

If you install solar panels that can be charging up the battery pack and feeding it from early morning to very late afternoon, then it can work out in a place like AZ.

If you do need to supplement, you can always just use a AC - DC charger to keep the batter pack charged up, or buy a DC generator.

In a place like AZ, if you can take even 75% of the air conditioning load off grid, then this is at least half of your load. Even better, it takes it off during peak demand billing periods.

 

[dopeassjackson]

The thing I don't like about mini-splits running directly from panels is that the need for cooling comes long before the sun is high enough in the sky and lasts long after the sun sets in my area. Seems so much more effective and useful to just rujn those panels to the main system and run the mini-split from the same system. Solves ALL of the problems with panels not getting used or the A/C needed it run when it's not sunny.

I get there are plenty of really good use cases for these systems. But they are a niche that should be used only when required.

I think all of them have AC inputs. I just dont see the need to run all that electricity through your charge controller, batteries and inverter if they can be ran directly off pannels for 6-10hrs a day. Pannels are nearly the cheapest piece of the solar system, they can be found "new in box" for prety cheap these days.

For my offgrid weekend cabin uses I see them working really well for keeping humidity low and temps down/up. Same could be said for something like a garage or outbuilding.

 

[kscessnadriver]

I’ve got 6 panels left of the 2 pallets of 31 I ordered. No real use for them, so using them to run a mini split for my garage, where the batteries are kept, makes sense for me