Anyone have experience with these "solar assisted" air conditioner/mini split?

[Mike90250]

I'd go simple grid tie, and get the best mini-split. Cheap is not always the best.

[J.P.M.]

So do you guys think it makes sense to get one of these systems and dedicate some panels to it.

VS.

Get a grid tie inverter and feed the system (even without net metering, as my system wouldn't be big enough to roll anything back yet) and get regular mini-splits with inverters?

I feel like the cost savings in the these (not needing an inverter) is attractive.

But then there is the waste of energy from the PV panels if I oversize it like I would probably do, so that even on cloudy days most of the energy is coming from the PV panels.

Get a grid tie system if it makes economic sense and use it to reduce your electric bill. Then, if you wish, get HVAC equipment that best suits your needs that drwas power through your electrical panel. Better, simpler, cheaper, more flexible, more options. The HVAC application doesn't care where the power comes from.

Also, claiming higher HVAC efficiencies by virtue of "free" PV power is simply lying B.S. Period.

[Gilligan]

Get a grid tie system if it makes economic sense and use it to reduce your electric bill. Then, if you wish, get HVAC equipment that best suits your needs that drwas power through your electrical panel. Better, simpler, cheaper, more flexible, more options. The HVAC application doesn't care where the power comes from.

Also, claiming higher HVAC efficiencies by virtue of "free" PV power is simply lying B.S. Period.

Well, to be fair, they have inverters in them to run variable high-frequency drives.... so they take AC and turn it into DC then turn it back into 3 phase AC. So supplying DC eliminates that rectifying step and probably does make it more efficient.

But by how much? Probably not as much as they are saying.

[J.P.M.]

Well, to be fair, they have inverters in them to run variable high-frequency drives.... so they take AC and turn it into DC then turn it back into 3 phase AC. So supplying DC eliminates that rectifying step and probably does make it more efficient.

But by how much? Probably not as much as they are saying.

Get a grid tie system that supplies power to the entire load and if you want, size it only for the annual electrical HVAC load however you choose to meet that load. Better, cheaper, faster, more flexibility. KISS.

[Gilligan]

Get a grid tie system that supplies power to the entire load and if you want, size it only for the annual electrical HVAC load however you choose to meet that load. Better, cheaper, faster, more flexibility. KISS.

I didn't mean to sound like I was disagreeing.

I was just stating that TECHNICALLY they MIGHT be some efficiencies gained.

But I am in agreeance with everyone here... probably negated by what I could push back into the rest of the system which would also offset the cost of the inverters.

[neweclipse]

Inverter in mini-split is no help when not in use or switched off...whole-house inverter ready whenever sun shines...

[Gilligan]

Inverter in mini-split is no help when not in use or switched off...whole-house inverter ready whenever sun shines...

Agreed... but my AC runs 12 hours a day now and doesn't keep up... I end up at 85* at the end of the day when I finally turn the thermostat up and go home.

[Mike90250]

....Agreed... but my AC runs 12 hours a day now and doesn't keep up... I end up at 85* at the end of the day when I finally turn the thermostat up and go home.

Well, that's a whole different problem, tightening up the building envelope and insulation. Or throw more gear at it

[Gilligan]

Well, that's a whole different problem, tightening up the building envelope and insulation. Or throw more gear at it

I've covered this in another thread... but bottom line is, yes, there are major insulation issues and air leaks, but secondly we are a print shop... so we just plain generate a LOT of unavoidable heat.

[Gilligan]

Even if we spent 6-10 THOUSAND on insulating... we still wouldn't keep up... so the net gain there would just be lower temps with zero reduction in cost.

[J.P.M.]

I've covered this in another thread... but bottom line is, yes, there are major insulation issues and air leaks, but secondly we are a print shop... so we just plain generate a LOT of unavoidable heat.

Dump the excess heat when not needed via ventilation. Ventilate less when space heating is needed.

[Gilligan]

Dump the excess heat when not needed via ventilation. Ventilate less when space heating is needed.

We do as much as we can (well, there is still one more small part we can do).

We have one of the most efficient dryers on the market. The cabinet is cool to the touch, we set our phones and drinks on it while we print. Coming out is a bit of capturing we could add... but that wouldn't help a whole lot.

The other sources can't be captured.

[bcroe]

The reason to use net metering, is any time you do not need max cooling, you can save up some
reserve that would not happen with panels into the mini. Most likely this will completely override
losses of an extra conversion step at the 300V level. With more panels this will be more
significant. And you will be less limited in selection of conditioning units. Bruce Roe

[Gilligan]

The reason to use net metering, is any time you do not need max cooling, you can save up some
reserve that would not happen with panels into the mini. Most likely this will completely override
losses of an extra conversion step at the 300V level. With more panels this will be more
significant. And you will be less limited in selection of conditioning units. Bruce Roe

But we will almost ALWAYS need max cooling, except for weekends when we let it get 82*... and even then it probably runs balls out to stay there! LOL

[NochiLife]

My 2 cents is this: it sounds like high heat is a problem in the shop regardless. If you are not planning to get seriously into solar electric for powering the shop, a solar-assisted A/C will be a lot simpler than a net-metering system (not to mention easier to install). Depends how far you want to go with the solar idea. Don't think you'd need permits and inspections to install a solar-assisted A/C--but if you want to backfeed into the grid, there's (rightfully) a lot of red tape.

One other thing to keep in mind is that you might want to have someone estimate/calculate your heat load, so you don't end up throwing money at a problem without realizing the extent of it. It's one thing to cool down a space--but it's a completely different issue if there's a lot of heat being generated in that space.