Pioneer Air Conditioner WYS009G-22 Wall Mount Ductless Inverter++ Mini Split Heat Pump, 9000 BTU-208/230 V

We've had this air conditioner (12,000 BTU version) running for several days now and it is so fabulous. I've never had any air conditioning system (central or window) work as nicely. Basically the house magically stays cool and otherwise you can't even tell that the unit is on. Technically if you listen very closely you can sometimes hear the fan just barely. It's doing a good job keeping 700 ft.² nice and cool when the outside is in the mid-80s.The installation process itself is relatively straightforward, but you definitely want to watch some YouTube videos first to make sure that it's something you are comfortable doing if you haven't done it before. I actually ordered the unit with the Amazon Professional Installation option but that totally failed because Amazon canceled the installation after a few days saying that they couldn't find anyone in the area to do the installation (despite being in a major metropolitan area). So I was left to do the installation myself. I had never run metal conduit or connected up copper refrigerant tubing, etc. but found that it was a moderately straightforward if a somewhat lengthy process. Certainly it would be a lot faster the 2nd time or if I already had electrical run to the area where the unit was being installed.The installation instructions from the manufacturer are complete though I think they could improve them slightly to make the installation process even smoother. For example, they don't mention that you'll need to elevate the unit on blocks if you want to be able to put the drain joint in the bottom of the outside unit (only needed for heat pump operation). And other small details could be improved in the manual to make things slightly more intuitive. But everything can be figured out from the installation manual, it just takes a little bit longer to figure things out. Still, I should probably be commending them for making a mini split unit like this that can be installed on a DIY basis by someone who has relatively little experience the techniques involved.Summary: 5 stars for the unit which is super quiet and cools nicely, 4.5 stars for the installation instructions, and 0 stars for the Amazon professional installation that didn't pan out (but not a Pioneer problem, just an Amazon problem).edit: Still easily keeping things cool inside today when it was over 90 outside. Btw, expect to spend around $300 on additional supplies for the installation, depending on how far you need to run electrical conduit, how you are mounting the unit, whether you want to install a separate cover over the line set, etc.

Our 1927 home had unique challenges when installing A/C, even though my husband is an HVAC-R technician. Due to the construction of our home, neither the A/C nor an adequate heat source was able to be installed in our kitchen, so we have relied on fans, small baseboard heat and space heaters. This year I was searching as this summer promised to be hotter than normal. I found this unit and with approval from my husband, we bought it. I can't say enough wonderful things about it. Granted, he's a professional, but the installation was fairly easy. The unit sits outside and I can't hear anything when it's running. I typically just have it on the "dry" mode to take humidity out, and the kitchen is actually frigid at times with the temp set to 75 and the inside operation is completely silent as well. I don't have to worry about sweltering in the summer when I cook, and I'm looking forward to the having the heat pump in the kitchen this winter as our temps can be frigid in WI. The kitchen has gone from the least comfortable room in the house to the most comfortable room in the house thanks to this unit.

The 12K BTU unit worked really well this winter in Seattle area. My electric bill went down to about 1/4, from $840+ (electric furnace) down to $215 for two months! And more comfortable temperature, too, in the living room. We set to 71F and leave it like that without worrying about lowering or set-backs at night. In a room with very large windows on south/north walls, the temp is usually from 66F - 69F about 16 feet from the indoor unit, depending on the temp outside. When it was 20s outside, the living room could be as low as 63F farthest away from the indoor unit, due to heat loss through the large windows.I expect to recover the cost of purchase and installation within a year. I installed myself, after lots of online research and careful planning. It was a somewhat advanced DIY project: simple carpentry, HVAC background, electrical code know-how.I happened to have unused, dedicated 220v lines from the electric panel, that ran to what most likely used to be a hot tub area, judging by the thick wires. So, I did not have to pay for electrician. I bought a vacuum pump, micron vacuum gauge, torque wrench, circular saw all for about $250. I probably worried about the pressure test the most, but the pump was able to draw to a really low micron reading after tightening the connections to the required torque specs. I mounted the outdoor unit to a simple wooden platform attached to fence posts. I had to loosen the bolt connecting the fence post to the house siding in order to not hear any vibration or humming.