DIY Mini-Split Installation

[Zeitgeist 13]

We're about to have a solar array installed on our roof, and would also like to replace our aging natural gas forced air furnace. For starters I'd like to install a couple evaporator wall units up stairs, where the heat rarely makes it. This is a well built 1936 house, but it's not the most thermally efficient shack around.

So I guess my question is really about settling on a decent setup, as well as the tools required to charge the units. I know I'll need a gauge set for R410a, as well as a quality flaring tool. I already have a big ol Robinair vacuum pump. Based on the size of the space needing heat/cool I've determined that I'll need an 18,000 btu dual zone setup. Other than that, I'm caught in a paralysis of analysis given how much of an investment this is for us.

Any DIY folks ever tackled one of these installs?

TIA
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[raydog]

With the equipment, line sets, misc., plus your gauges, hole saw, and assuming you will need an electrician, you will probably be around $3500 - $4000. And hoping you installed it properly.
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Come on, It's not rocket science. KISS

[Zeitgeist 13]

Thanks, that's about my cost estimate as well.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[Q-Dog]

I've looked into these only a little bit and there are some precharged units that only need the lines to be vacuumed. Seems like not a difficult thing to do.
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Brian

'69 Dune Buggy
'69 Beetle Convertible
'70 Beetle

[busdaddy]

I wonder how that works?, quick disconnects and some extra pre charge for X length of line?

I've done a little research previously, since I've already got the equipment for auto A/C it can't be much different, around here the recommended refrigerant is hard to find retail though. I see Red tek and other makers of the propane/butane blends also offer blends for residential A/C and commercial refrigeration, that stuff claims you can charge without a vacuum and moisture in the lines isn't an issue.

If I do end up going with a split system I think I'll go make friends with a HVAC guy, they all drive a truckload of tools and supplies home every night, maybe one of them does a little moonlighting on the side too? I guess you could also just ask an HVAC outfit if they will charge someone else's work and get a quote if there's warranties involved.
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[raydog]

Precharged linesets are fine, but you still have to pull a vacuum on the head unit. It comes precharged with nitrogen. Having to do this kind of negates using them.

The outdoor unit also comes charged with enough refrigerant for 75 - 100ft of lineset, depending on the unit. Typically, just keep it simple and evacuate the lines and head unit at once. That way you can check for leaks too. No additional refrigerant need unless you exceed the rated length of piping.
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Come on, It's not rocket science. KISS

[Zeitgeist 13]

Yeah, I originally planned on the pre-charged units from Mr Cool, but the expense of the added lines to reach between the condenser and evaporators was cost prohibitive. I'd rather invest that money into the tools, so I can use them to do the downstairs installs at a later date.

That's interesting that there are hydrocarbon blends for HVAC. I run a blend of propane and isobutane in my Vanagon and both 124 Mercedes. R410a is surprisingly expensive, but it seems to be readily available online.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[skills@eurocarsplus]

[djkeev]

I've done three installs using the MrCool DIY precharged units.

Every component comes charged.
When you fasten them together the port seal gets pierced allowing the refrigerant to flow.
There is no evacuating or charging to do at all.

A major plus is that The electric feed to the Evaporator is bundled in the hose package.
The Evaporator thermostat/control pad is a wireless remote control.
Just wire up the Condenser unit and plug everything in.
Yes, the charged hoses aren't cheap, but oh so easy to install!

Very easy
Very cost effective
Work very well on cooling and Heat.

I'm talking to a person today about doing a 3 zone MrCool system.

The only downside is because you cannot cut the hoses to an exact length, you will have excess that you need to neatly tuck somewhere.
But that is the ONLY downside that I've noticed.

I'd not hesitate on using the MrCool DIY system!

https://mrcool.com/diy-multi-zone/

https://iwae.com/shop/27k-btu-22-seer-mrcool-diy-3...MoQAvD_BwE

Dave
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[Erik G]

I helped someone do a Mr. Cool. Easy peasy. Buying 2.5 lb R410a is no prob anyways. You do need an adapter for the low side, the mini splits are different

[AZ Landshaper]

Ive installed two Mr Cool units and like stated above there was no need to charge or vac and the systems work flawlessly. Makes my garage useful when its 110 outside.
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[Zeitgeist 13]

I'm loving all the kudos for Mr Cool. I'm reconsidering my choice to charge my own sauce, as the fine print does indicate that I need a EPA 609 Type II certificate for larger quantities, or just a 609 for 2.5lbs or less. The YT vids I've seen all indicate a fairly straightforward install with no evacuation or charging. I just need to settle on a good location for the compressor/condenser unit to minimize the length of charged hose required to feed the two air handlers.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[Zeitgeist 13]

An interesting bit of trivia I just found out is that most of the brands we get here are all made by a huge Chinese firm Midea. Senville, Mr Cool, Pioneer, etc are all re-brands made by Midea. Midea owns Kuka, which is the German robotics manufacturer used by nearly all the Euro car makers in their factories, including VAG.

And now you know.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[busdaddy]

Well I pulled the trigger on a Senville 12K BTU mini split unit, the kit came with a remarkable amount of the stuff needed, I still had to source specific mounting hardware for the compressor, as well as wire, conduit, circuit breakers, etc.., and an adaptor to hook up my gauges to R410a. And boring a big hole through a 50 year old wall with no idea what's inside was interesting.
The instructions were fairly in depth, but took 4-5 reads before it all made sense, go slow and review.....

The outdoor unit comes pre charged with enough gas for 16-25 feet of line, longer than that and you have to add refrigerant. You have to pull a vacuum on the system before opening the valves on the compressor and letting the gas loose into the rest of the system, the usual leak detecting protocols apply.

So far so good, it blows cold, but it's still Juneuary here so no real hot weather reviews yet, supposedly it heats as well but I have yet to get that far into the instructions for the remote control.

I have to say it's remarkably quiet compared to the window mounts we've been using, I could have gotten away with placing the compressor much closer to the patio, it's no where near as obnoxious as I expected. I wouldn't want it on the porch, but right beside it wouldn't bug me much.
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Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[Da TOW'D]

I did a Senville mini-split unit last winter.
It came Pre charged and so we bought a vacuum pump and good vacuum gauge.
Just a few large wrenches needed to connect the piping. We wired it to the 220 breaker that was on a unused baseboard heater.
We heated with wood furnace before .
I'm impressed how well they work.
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