Pioneer Mini Split Air Conditioner: Installation and Review


We recently installed a desperately needed air conditioner mini split with a heat pump in our home. It cost us about a fraction of the cost by doing this ourselves compared to if had we chosen a more expensive brand unit and had it installed for us.

Since our website mostly deals with indoor air quality anyway, we’ll be sharing our install, step by step.

DISCLAIMER: This post should be considered an example of our work only and we are not liable for anyone else’s project or experience. Always make sure to consult with a qualified and licensed electrician and HVAC technician. Do not work with live electric wires or refrigerant if not qualified to do so.


What We Bought

Pioneer Mini Split with Heat Pump

We bought our mini split system from Amazon from this seller. This is from the WYS series of air conditioners and is manufactured by HighSEER. It operates based on an inverter with a heat pump.

We bought the 24,000 BTU size (WYS024), which is what will be shown in this post. Keep in mind that smaller units will look different and may require a lower voltage to be hooked up to it. They may also have different size and length connecting pipes, so make sure to adjust to your specific installation manual as you do your own install.


Other Things Needed to Buy

If you have most of the tools on hand already, you’ll need to dish out at least $50 extra on top of the A/C. At minimum, you’ll need things like:

  • breaker
  • electric cables
  • A/C disconnect box
  • some sort of mounting pad, brackets or concrete blocks/pad to put the outdoor unit on if necessary
  • insulation and some sort of decorative cover for the cables on the exterior of the house


Why We Chose the 24,000 BTU Unit

Before we go into the install, you’ll need to decide what size mini split you need to buy.

The Pioneer comes in sizes between 9,000 BTU and 36,000 BTU. The smaller units (12,000 BTU and below), you’ll be able to choose between 110/120V or 208/230V. Units larger than that have the 208/230V voltage only.

The unit we bought was for a 450 sq. ft. West-facing garage in Georgia that’s used as an all-day workspace. Only the garage door was well-insulated, with an attic above it.

Even though the unit size we selected could probably work in a space that’s about as twice the square footage of ours, this is probably most realistic for a normal, well-insulated area only.

For reference, coming to this garage workspace in the early morning during the winter usually means it’s 30°F to 45°F outside, while in the summer early evening, it’s 90°F to 98°F usually. We struggled to heat it before noon in the winter and to keep it cool after noon in the summer, unless we worked odd hours.

We had a portable A/C in there (rated at 14,000 BTU), thinking that it would help at least somewhat if we ducted it correctly. It helped cool things down by only a few degrees, while shooting up our utility bill in the summer. It made working in the garage just “bearable”, but nothing more than that.

We probably could have gone with the 18,000 BTU unit with the Pioneer mini duct air conditioner, but given our experience and regrets with the portable unit we had already, we just didn’t want to take a chance again.

So we just went with the 24,000 BTU unit to be safe.



Delivery of the mini split system was relatively easy.

Within 2 business days it was delivered to a nearby city, and we were texted a number to call to set up a freight delivery appointment. It was dropped off in our driveway and we signed for the delivery less than 24 hours later after the driver called us one more time to confirm.

We were probably lucky though since the company that shipped this to us was in Florida and we’re in Georgia.

There are 3 pieces that came shrink-wrapped on a palette. Basically, the indoor unit, outdoor unit, and a box of accessories.



What’s Included with the Mini Split System

Unpacking it, it looks like this:


Outdoor Unit

It wasn’t too heavy. Two people can carry it using what appear to be handles on the side, in case you’re wondering.


Indoor Unit



For Indoor Unit

The indoor unit comes basically with:

  • an installation manual
  • an owner’s manual
  • another owner’s manual for the remote control
  • the remote control itself, 2 AAA batteries and a plastic holder to mount it on a wall (be mindful that not all units come with the wall mount holder for the remote control, but ours did)
  • a drain joint, seal, some screws and nut bolts
  • a drain hose




For Outdoor Unit

The third box on the palette was the accessory box for the outdoor unit. It came with:

  • 16 ft. long connecting copper pipes – in OUR case
    • liquid side was 3/8″ and gas side was 5/8″ for our 24,000 BTU unit
    • they already had ready-to-go copper tubes with nuts on each end (although we ended up cutting ours shorter and flaring it as you will see later)
  • black electrical cable
  • other accessories to run those through
  • it also came with some black rubber pads to install the bottom base (not shown)



Step-by-Step Install Instructions

Our install can be summed up in several stages:

  1. Position and install mounting plate for indoor unit.
  2. Run pipes through the back of the indoor unit to the outdoor unit.
  3. Install the indoor and outdoor units themselves.
  4. Do the electric work – install the electric breaker, disconnect box, and run the wiring between.
  5. Test and run the system.


Here it is in detail:


Position and Install Mounting Plate

For now, you only need to position and install the mounting plate without the indoor unit.

The manufacturer recommends having this much free wall space around the indoor unit:


You can go more on the left, right, and top if you wish. In the next few steps, we knew we needed to install a hole for the piping on the left based on our configuration, so we wanted to be generous here to avoid our piping from bending too much. An 8″ distance to the left seemed to work for us.

There was some narrow shelving under our unit we initially were going to remove later on, but after we tested the air flow and temperatures, we decided to keep them after all.

Once we decided where to mount the indoor unit, we unscrewed the center screw of the metal plate on the back of it with a Phillips screwdriver to release the mounting plate.


We then used a stud finder to drill into studs and made sure everything was level before we attached the mounting plate.



Prepare and Mount Inside Unit

Next, we drilled a hole 8″ away from the mounting plate, using a stud finder to make sure we’re drilling in between studs this time. In our case, the hole was on the left side of the unit. We used a 2-1/2″ wide core bit if you’re wondering how big the hole was.

We drilled through the inside wall and the cement siding on the outside. The plastic piece that goes in between arrived slightly damaged as you can see, but it wasn’t a big deal for us.



Next, we pulled the piping and electrical cable through the hole. We did the copper ones first (as shown), then pulled the black electric cable and drain hose later.

You’ll need to twist them slightly later on before finishing as it’s recommended that the drain hose be at the bottom so that its water doesn’t drip – we came back later and made sure we did this once we were finishing things up.

We also could have wrapped everything together at this step, but we decided it was easy to do this later as well since we needed to test that everything works first.



Next, we cut out a “knockout panel” on the inside unit on the same side where the hole in the wall was.



Now that one side of the copper piping and drain hose were out the exterior wall, the other ends needed to be fed through this knockout panel so that they could connect in the back of the inside unit.



The piping connections are made directly in the back of the unit, in the center.

We first released the nitrogen out of the green valve, then connected the two parts of the plastic drain hose. We also connected the copper pipes using sealant and tightened everything up with two pliers.




The last thing to do in this step was to hang the inside unit. It hangs from the screws in the top first, then is supposed to click into place at the bottom once it gets flush with the wall.



Position and Install the Outdoor Unit

Installing the Base

The outdoor unit must be installed based on where the pipes are, but there must be a bit of room since the pipes are stiff and shouldn’t bend too much. While we were doing this, we readjusted, wrapped, and insulated our pipes and cables at the same time.

We didn’t need anything fancy, so we simply put our unit on four concrete blocks and used the black rubber pads in between that came with the unit. We used a Bosch hammer drill for the holes, then secured the outdoor unit using 4″ long hammer drive anchors.

Very important – the unit must be level at all times!



Cutting and Flaring the Copper Piping

Next, we cut and flared the copper pipes. Our pipes were originally 16 ft. long and we cut them down to about 11 ft.


Tools necessary:

Pipe cutter (we used the Ridgid shown here); ours, clearly a decade old:



Flaring tool (we bought the Husky shown here from the Home Depot):



Now, for the steps on how to do this:

After cutting the pipe, we inserted the brass nut. It’s important to double check you did this – once the flare is done, you won’t be able to put it on.



Then, simply insert the copper tubes into the correct slot. Since our tubes were 3/8″ and 5/8″, each went into the corresponding slot in the flaring tool.



Then, it’s as simple as tightening the handle on the tool until the tube is flared.



And to finish off this part of the project, we screwed on the pipes to the unit using the nuts, sealant, and two pliers again (as shown before).



Do the Electrical Work

This will depend on the system purchased, but the wiring required for ours looked as follows (on page 16 of the manual):




As you can see, both configurations are essentially the same. The only difference is whether you’ll have a second 110-120V line or a neutral wire.

We’ll be working with the 230V configuration for our unit.

The nameplate on the side of each unit states the maximum current that needs to be followed when buying things like the breaker, disconnect box, and cables. Ours gave us a range from 20 to 30 Amps.

Along with a cable to run to the fuse box, we also bought a disconnect box and breaker for 30V:




Before doing this, however, we prepped the wall and the disconnect box.

First, we cut out two holes in the disconnect box and hung it on the exterior wall. We also cut the sheetrock and ran a cable between the fuse box and disconnect box.



We then connected the black and white cables to the breaker we inserted, checked the voltage with a meter, and moved on to work on the indoor unit.



The Klein Tools meter we used can be found here.

On the disconnect box outside, we connected the other ends of the black and white cables, grounded with the green cable, and tested the voltage to make sure it’s 120V each and 240V together here as well.



By the way, while we were doing this, we covered the cables up with grey conduit pipe.




Next, we lifted the indoor unit’s top panel and removed the white wire cover on the right with a screwdriver, which revealed the terminal block.



We fed one end of the black signal wire towards the terminal block – the other end was outside. After stripping the wire on the cable, each individual wire was then connected to the corresponding position on the indoor unit. In case you need guidance on the color-coding, there is a diagram under the top panel that is lifted up on the top indoor unit. The colors weren’t exactly the same, but it was manageable.




Next, we made the wiring connections to the outside unit.


Before wiring:



After wiring:




After putting back all covers, it was time to test the unit.


Test and Run the System

The unit seemed to do fine. At first glance, the A/C was cooling fine since it already came charged with refrigerant, but we proceeded to do a test for pressure and leaks. Note – you have to be licensed to work with R410A refrigerant, which we are.

Next, we connected the vacuum pump to the low side (the smaller copper pipe). After running the vacuum pump, we tested for negative pressure for about 30 minutes using our Yellow Jacket manifold gauge. It held under the zero to -30 Hg range the entire time, so the pressure held just fine as is. There were no leaks.

After another hour of maintaining the pressure, we took the caps off the king valves on both pipes using a folding Allen key.



Once we tested everything on the unit, it was time to screw the caps back on the pipes.

As far as our temperature test, here’s how it went. We installed the unit in mid-April. It was 86°F outside. We waited 45 minutes in between each step.

Cool setting at 69°F, highest auto fan setting:



Heat setting at 82°F, highest auto fan setting:



Now that our unit seemed to work just fine, it was time to put a decorative cover on the piping coming out the exterior wall. There are decorative line cover sets like this one, if you want yours to look neatly.

We happened to have a vinyl gutter lying around unused that we cut up lengthwise with our power saw and secured to the wall.

It worked for our purpose, and this is how it all looked when it was all done. Not bad considering that most of the things around the outdoor unit were things we had lying around in our shed.



Conclusion and Review

Overall, this was a good buy. The unit is a fraction of the cost of the Mitsubishi and other brands we’re used to working with. The indoor unit looks stylish and isn’t an eye sore. The piping on the back of the indoor unit could’ve been configured better and so could the colors on the electric wiring. But overall, it was worth it and this project only took an afternoon to do.

Within 15 minutes of use, this unit was cooling just the same as the main air conditioner in the rest of our home. We’ll be taking down the disappointing portable A/C we had in the garage before this mini split very soon. Just wish we had paid up the extra cost and bought this mini split air conditioner years ago instead of the cheaper, portable one we had before that.

The Pioneer air conditioner also has a few interesting features we didn’t expect (accessible from the remote control).

Some are standard, like a timer or energy-efficiency mode. Others are a bit more advanced like the vacation mode to prevent the unit from freezing over or the cleaning function to clean bacteria that accumulate on the heat exchanger. This system also comes with a dehumidifier, so it could work great in humid basements as well. There is a Wi-Fi function available, but we didn’t see the need to purchase any extra accessories.

We had a minor question we asked the manufacturer on Amazon, and within less than an hour, we had a response. So far, we’re happy. We’ll be updating again as we get into summer and winter.



  • End of April (3 weeks after install) – The temperature dropped down to the high 50s and low 60s due to storms, with mid-30s in the morning. We simply turned the heat on early in the morning, and within 15 minutes the garage was warm enough to work in. In fact, setting it to 80°F became too hot, while setting it at 75°F kept a warm breeze circling around the space throughout the day.


Frequently Asked Questions

Will this unit need freon/refrigerant?

These units come already charged with R410a refrigerant, but the answer to this question will depend on how well your own unit is cooling.

As you can see in our instructions, we did a test to primarily check for leaks, but we did not need to add any refrigerant in our case. The unit was cooling just fine. Update: 3 months later (in July), when we had 95°F weather, the unit was still cooling just as fine and there was no need for added refrigerant.


Will I need to cut and flare my pipes too?

We cut our copper pipes down from 16 ft to about 11 ft for two reasons. One, a shorter pipe makes the unit more efficient and bend less. Two, we needed to cut the pipe because of the way our indoor and outdoor units were positioned.

Flaring was fairly simple. Depending on how your indoor and outdoor units are configured, you may or may not have to do this as well. But other than the $40 tool we bought, it took less than 15 minutes to do for the two pipes.


What if the 16 ft pipes are too short and I need longer ones?

You’ll have to buy a separate copper line set or extension specifically from Pioneer and it should come pre-flared with the appropriate nuts just like the original pipes do. Don’t forget to buy the correct sizing, as the piping diameters of the liquid and gas side will depend on your unit size.

Also, remember that the piping length and drop is proportional to the BTU capacity on your unit and has its limitations (check page 25 of your installation manual). There is no need to add or take away from the refrigerant just because you happen to shorten or extend the lines, unless your lines will need to be at least 25 feet long overall.


What kind of breaker will I need?

Technically, you could get this information on the Amazon product page before you purchase, if you look for the Specifications pdf document. But, you’d be wise to wait for your unit to arrive before you go buy any breakers.

Once our unit (WYS024) arrived, it stated on its side panel that our minimum circuit ampacity was 20A, while the max fuse/breaker was listed at 30A. This was different from the specification sheet on Amazon, which is why we went with a 30A breaker.