Picture below - says it heats and cools. For an AC like this,

  1. Are regular "refills" needed, like changing water/cartridges?
  2. Can I reasonably install it myself? I'm no DIY expert
  3. (Optional) Is annual maintenance priority (and can I do it myself)?

Edit: thanks all, I decided I'll suffer instead

The closest place for the mini-split's second half is too far (& other issues), and I couldn't find anything else that either works in my setup or is affordable. I decided I'll move the fan to point blank range; turns out, not so bad, fan + sweat = cool

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    If you want to do it wrong then it will probably take you 10 hours. If you want to do it right then you'll probably need 30 hours. If you pay someone competent to install it then they would probably take 3-5 hours.
    – MonkeyZeus
    Commented Aug 10, 2023 at 12:29
  • Something worth considering is safety, and neatness. Can you do the trunking and piping as neatly as a professional, and is there a risk of the outdoor unit dropping on someone's head? Commented Aug 10, 2023 at 15:16
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    Don't take this wrong OP, but if you are asking if an AC requires waters refills you are most definitely outside of what you can do on your own. Commented Aug 10, 2023 at 16:23
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    @VladimirCravero No offense taken, but as I see such reasoning now and then, let me just say it is complete nonsense. Commented Aug 10, 2023 at 22:43
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    @VladimirCravero, or the OP is installing a swamp cooler.
    – Mark
    Commented Aug 11, 2023 at 3:36

5 Answers 5

  1. No. It may need a refrigerant refill at some point but that's more an indication of a problem than a maintenance item.
  2. If you're asking this question, you probably shouldn't attempt it. That isn't meant as an insult. Just off the top of my head, you need to have a decent idea of how ACs work, how to mount things on walls, how to route things through walls, and how to wire things like this. The wiring could set your house on fire and/or kill you if done wrong.
  3. The answer you link to pretty much answers that question. You can do without it. Doing things like cleaning it, checking for leaks, etc you can do yourself. If there's a problem, you're probably better off calling someone in to fix it.

That looks like a minisplit heat pump system.

If so, there's a compressor unit that lives outside the building. Plus a manifold if you want to run morethan one wall unit off that compressor (mine is handling five). Plus insulated hoses and connecting wires. Plus a circuit breaker big enough to power this system and the weather-safe electrical connection to the outside unit with cutoff switch. Plus the work of routing (and covering?) the hoses and wires.

I like mine, but I had it professionally sized and installed. (Though the pros did miss a bet or two.)

  • How long is the connection to the outside part? Can they live 10 meters apart? "circuit breaker" is that plugged in to a wall with a cable plug? (yes I'm an idiot) Commented Aug 9, 2023 at 21:19
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    @OverLordGoldDragon How far apart the 2 halves are will vary from system to system. 10 meters sounds a bit far. Circuit breaker is the thing that protects the circuit from faults. It lives in a box that all the power in your house comes in through. I personally don't mind answering easy questions but "what is a circuit breaker" is pretty low hanging fruit and you could get good answers quickly by googling. Commented Aug 9, 2023 at 21:25
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    No plug. Hardwired to its own circuit. Ten meters is possible with at least some systems (I have a run that's about that long). Basically, you need to start by learning more about minisplit heat pumps in general, than decide whether it's the right answer for your house or whether you want a single througb-the-wall AC.
    – keshlam
    Commented Aug 9, 2023 at 21:27
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    @OverLordGoldDragon The AC you're asking about would get its own circuit breaker in the same box as all the other circuit breakers (and possibly more in its own little box, I'm not an electrician, sorry). The circuit breaker does not plug into a wall outlet like a lamp. Commented Aug 9, 2023 at 21:35
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    @OverLordGoldDragon it's perfectly reasonable that you apparently know "absolutely nothing" about basic electronics in a house. But you really cannot and shouldn't keep asking more and more extremely basic questions about now totally unrelated topics. (For example, on this road, next you will be asking very basic questions about tools.) Simply google those topics, and/or watch any of the myriad videos which exist explaining these things.
    – Fattie
    Commented Aug 11, 2023 at 13:14

What you're looking at is a mini split system similar to the one shown below. It has the unit pictured in your question plus a compressor which is installed outside and usually wired for 240 Volts. There are tubes that run from the compressor to the inside unit. These can be installed by a DIYer but might not be a good idea unless you've got some good knowledge on how AC units work. You don't want to void warranties because you made a stupid mistake. The maintenance would be minor, cleaning coils and fan blades on a yearly basis. The unit wouldn't need to be charged unless there was a leak somewhere.


enter image description here

  • Mini-splits "can be installed by a DIYer" in the sense that it is physically possible, but that does not mean it is allowed. Handling the refrigerant without the required training and certification is illegal in many countries.
    – TooTea
    Commented Aug 10, 2023 at 12:40
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    @TooTea That is correct but most mini splits are pre charged and don't require any handling of the refrigerant.
    – JACK
    Commented Aug 10, 2023 at 12:50

Are regular "refills" needed, like changing water/cartridges?

They shouldn't be.

Can I reasonably install it myself? I'm no DIY expert

As I understand it.

A mini split is as the name suggests "split". You have two units, the "indoor unit" and the "outdoor unit".

In a conventional air conditioning unit, the indoor unit contains the evaporator and while the outdoor unit contains the condenser and also usually the compressor and accumulator. In a "heat pump" unit there are extra valves such that the two coils can switch roles. When you switch from aircon mode to heating mode, the outdoor condenser becomes an evaporator and the indoor evaporator becomes a condenser.

The two units are connected with a pair of pipes called a "line set" which carry liquid refrigerant from the condenser unit to the evaporator unit and refrigerant gas from the evaporator unit to the condenser unit.

The system is designed to be sealed, refrigerant needs to stay in, and air and water need to stay out. The majority of air conditioning systems use fluorinated compounds as refrigerants. Sale of these refrigerants and work on equipment containing them is restricted in many places due to environmental concerns with refrigerant releases.

For a "package unit" where the whole refrigeration circuit is in one box, they can just ship the thing pre-charged and you just hook up the air ducts and the power and control wiring and turn it on. For a "split" system though things are a bit trickier.

Some equipment ships with all components open to atmosphere, after connecting the pipework and sealing the system the installer is expected to vacuum down and then charge the system.

Some split systems ship with the condenser unit pre-charged with refrigerant, but other components open to atmosphere. After installing the pipework, the installer must vacuum down the pipework and the evaporator unit, before opening the valves on the condenser unit to let refrigerant flow into the rest of the system. This saves the installer the effort of charging the system, but they still need a suitable vacuum pump and gauges to perform the evacuation.

In some countries you can get systems designed for DIY install where the air has already been evacuated from the components that are not pre-charged. The installer just threads the line set through the building and special connectors are used to join the system together and release the refrigerant while keeping air ingress and/or refrigerant escape to a minimum.

The downside of this approach is that the "line set" (the pipes that join the evaporator unit to the condensor unit) is a flexible assembly of fixed length that the user cannot shorten or lengthen and must thread through the building in a single piece.

At least on the unit's I've seen, In addition to the refridgeration lines, the indoor unit will also have a drain pipe to take condensate to the sewer.

(Optional) Is annual maintenance priority (and can I do it myself)?

AIUI the main maintenance needed is cleaning. The evaporator and condensor coils pick up dirt which restricts the airflow making the whole system less efficient and ultimately can lead to damage to other components.

The refrigerant is supposed to be sealed in the system, but some systems do end up with leaks. In some countries it is considered acceptable to top up a system with a slight leak, in others even the smallest leaks are supposed to be found and fixed before a system is re-charged.


Former HVAC here.

Short answer:
Yes you will need an expert for certain parts of the job.

To save money you could do all the setup work up-front. Hire pros to do copper, refrigerant and electric and initial startup with you.

My job in residential HVAC was to install the entire base setup for all heat and AC implementations. The base physical setup is just a bunch of effort anyone can learn eg. venting, mounting, copper running etc.

A word on running copper. It's obviously expensive and if you kink it you must throw it out and start over. Don't skimp on this because you want a really efficient refrigerant system on your AC units.

The final stages and initial startup are where non-professionals will be roadblocked and should get help to do things correctly and safely. Then one of the employees with a torch would come to "braze" the copper I had installed. Once the copper was vacuum sealed they would do the refrigerant. I eventually bought an acetylene torch and vacuum pump to do this process myself but I do not recommend it. I had several incidents where I could have permanently injured myself, eyes, explosions, burns etc.

In new construction the project's electrician would wire everything.

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    Good to get specifics on the wiring, much more complicated than I thought. I wonder why the wires don't just come pre-insulated so one simply links it to the circuit breaker... Commented Aug 12, 2023 at 11:25
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    Yeah agreed, there were better products like Trane vs Goodman. Goodman's had like barbaric wiring setups and the one time I tried it myself I blew an internal fuse on the mainboard. I must recommend getting an electrician to do the startup with you. Commented Aug 12, 2023 at 11:29

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