I installed this in a 100-year-old home with propane heat that usually burns 800 gallons throughout the winter to keep the house at 72F. When the price of propane shot up 50% in 2022 I decided to look into other options to save money. I installed this myself in an afternoon, but paid a HVAC technician $300 to pump the lines down and charge it. From November through March, my electricity bill increased an average of $150, but without having to pay for propane this unit paid for itself, the install, and the electricity it used in that time period. It starts to lose efficiency below freezing, and below 20F the temperature in the house dropped to the mid-60s. Our average daily temperatures rarely go below 20F, but if yours do you may want to get a higher efficiency unit rated for negative temperatures.
In the summertime, I was surprised to discover this setup also saves $50-$100 each month while cooling the house better- The central air conditioner is newer (replaced in 2018) but the blower fan consumes a lot of power just to move the air around the house, around 800 watts. We decided to install a window unit on the second floor (Midea U, also excellent units, and likely the manufacturer of the compressor in this mini split) to help on days when it's above 80F outside which will pay for itself this summer in energy savings compared to the central air.
I regret paying thousands of dollars replacing the central air system and furnace and wish I knew more about mini splits five years ago, with how well this unit works I doubt I will need to use the central system again. If you are heating with oil, propane, or electric baseboard heaters this system will pay for itself in the first year, and unless you have a high-efficiency heat pump with a variable speed blower it won't come close to this unit in terms of efficiency in the summertime either. I'm not even considering geothermal anymore as I don't think the potential energy savings would justify the installation cost in the long run even if I had to install a new mini split every 5 years.

Let me start by saying I have purchased 3 units from Sienville. They ate easy to install if you have generally mechanically inclined. Basic measurements and general knowledge can get it done.
The units are delivered by a freight company. FedEx freight has delivered all 3 of mine. This latest unit was destroyed in transit. The boxes looked like they had been run over by a truck multiple times. I opened the boxes and inspected the units. They sustained significant damage. I refused the shipment and units were returned. Amazon customer service was totally useless, they told me contact the seller - which was Amazon. Then they said contact the carrier, which I did and they started a claim. I was able to send a message to Sienville which I wasn't confident they would ever get it. To my surprise, they messaged me back and took my statement. They contacted FedEx and verified the claim was made and order refused. Sienville ad ised they would immediately ship a new unit and they would work the claim with FedEx, they would only contact me again about the claim if necessary. Extremely pleased with Sienville. Haven't had issues with any of the units. Very pleased and will definitely purchase again if given the opportunity.

100% recommend.

Installed over a couple days. Instructions are lacking but if you're mechanical you can figure it out. Youtube is your friend! Mounting the inside unit was pretty straight forward. I used the Senville mounting kit outside. I opted to provide my own 6" mounting bolts, going all the way through the studs from the inside to outside. Make sure you put at least four bolts in the top mounting rail.

I was concerned about bending the copper lines without damage. Turns out Senville has permanent springs (like the ones you'd use for bending pipes) wrapped around the copper lines where the tight bends will occur. The bends went easy, just take your time.

The install time will very much depend on your application. Things like, how far will you have to pull electricity, the path of the electricity, will you have to cut open a wall to pull the wiring? Will your outside unit be elevated, do you have a platform to work on or will it all be ladder work?

Something I didn't consider was the drain line. I ended up having to install a drain under a gravel parking area. Not a big deal but you should consider where the water will go. Oh, and this thing puts out water like a garden hose! Literally a steady stream, not dripping, but a steady stream!

Quality: It appears, thus far, to be really well made! I bought the 220volt 24K unit. The thing is super quite inside and outside. My Goodman units are much louder!

Performance: I installed the unit in a 30X40 garage with a 13' ceiling. The garage is very well insulated with no windows. So far, the unit has cooled it well and it has been hot and very humid.

I would but again and likely will buy again.

This has freed my attic window! No more noisy window AC.

Pros
* Efficient and powerful. It can easily keep my finished attic cool, even with the sun beating down on the roof and my gaming PC throwing extra heat into the room.
* Very quiet. (About the same noise level as my PC, and that is already pretty quiet)
* Installation was easy for a fairly handy person.
* Included WiFi/Smart function is a plus.

Cons
* No mounting diagram for the head unit. I had to draw up my own to make sure I get it mounted to some studs and avoid hitting a stud with the line set.
* No included cord grip connector for the head units power/signal cable. Not a big deal, but make sure you buy one of these before installation to save yourself a trip to the hardware store.
* The Alexa integration doesn't appear to take into account the units current status. So if you power it on through Alexa, and then turn it off using the remote; Alexa will still show it as powered on. This sometimes results in Alexa not working at all. I would try to turn the unit on and off and Alexa would show the command as successful but the AC was still powered off. The first time this happened the head unit was constantly beeping. No amount of Alexa commands or remote control commands would stop it. I had to pull the AC disconnect to forcefully restart the unit. Alexa also no longer reports the thermostat temperature. It constantly says 50f. The TLDR: Alexa integration is unreliable.
* In heat mode, the minimum temperature is only 5f, which for my area is inadequate. There can be entire weeks in winter where the temperature never goes above 5f. Senville does have higher end versions which operate at much lower temperatures. But my attic usually stays warm enough on its own during the winter time. Summers are the big problem, which this unit has so far proven to be more than enough for.

Notes:
I've owned this unit for 2 months now. I installed everything myself, but had a licensed HVAC tech flare the line set and fill the system (This is the minimum needed to get the warranty). I chose the 120V version since I already had a dedicated 120V 20A circuit for the old window AC. You get slightly better efficiency with the 240V version, but I did the math and after 5yrs of owner ship, the cost difference doesn't make up the purchase price difference. Though this may not be the case if electricity is more expensive where you live (I pay around $0.11/kWh). This also means I can keep the dedicated receptacle I installed since the circuit is staying 120V. The unit seems to maintain around 550watt draw, but will hit up to 1,200watts when the room is hot enough. It can draw as little as 150watts, especially when running in eco mode.

9K 110 volt LETO
2 full months of use MAY and JUNE midwest
This is my first mini split i've purchased and i installed it myself. Super simple to install, buy the vacuum pump and gauge set off of amazon. I installed my line set down thru the a 2x6 wall and ran them thru a 3" sewer pvc pipe incase i need to replace and to protect lines in the wall (much cleaner look, but more difficult to hang indoor unit as you can't mount it and connect everything on outside of wall per manual). I did not have a problem with bending hi/low copper lines nor did i have any leaks, i just pressurized it when releasing refrigerant from compressor and sprayed my fittings, i did not use nitrogen. I am running this 9K unit in my new office addition on house that is only 100 sqft, so my unit will probably wear out sooner due to short cycling, but its so quiet and better than a window or thruwall unit so i don't mind. I have 2 thermometers on my desk which is directly below unit (air blows over desk and circulates off wall behind me and back), with the system set at 73 my range is within 2 degrees of that but 90% perfectly at 73 it fluctuates more when i leave my office door open to rest of house.
I utilize the Honeywell/Resideo T5 and T10 thermostats between our 3 forced air HVACS, I am bummed i can not integrate this mini split in with those geofence settings, however the Alexa app i was successful in setting up geofence routines to control the mini split to change temps, i am not turning mine off completely, my away modes just increase cool temp by 5 degrees within 20 mile radius and 10 degrees within 100 mile radius for those longer trips. I've also purchased the Sensibo controller to see how it works (not impressed) but i do like the backup communication to mini split while away from house if i need it.

I had never heard of Senville before looking at mini splits and after doing a year of research i settled with Senville as their parent company owns some great hvac companies that are known for their quality.
I like this one so much i just placed an order for a 24K Senville Auro unit (better SEER rating and works when outside temp drops to -22 all this equals more money) to replace a 14K PTAC for our sunroom that can not heat or cool the room, and to help supplement the heat pump hvac on those hot and cold days.

This unit in cool mode is CONSTANTLY BLOWING air. I like it because i keeps air circulating i guess that why people set their units to turn off while gone but i honestly don't care, but when you pick out a place for your unit find a place you don't mind constant air blowing during the summer months and where you want the heat during the winter.

I can not speak yet on longevity nor operation in extreme temps, but am excited to see how it holds up. If you know how to change oil in your car and install an electrical outlet you should be able to figure this out and shouldn't be scared to install this yourself*, if you are unsure how to do electrical be smart and don't put yourself at risk.

*Note: if you install this yourself you DO NOT have a warranty, they make this clear but just incase.

Strongly suggest having whole house surge protector, i already installed one prior to installing the mini split, but i've read the board on compressor (outdoor unit) is usually what fails from lightening strikes and surges and is a pain to replace so keep that in mind.

I'll update my review if i have problems like sub 5 degree F temps, otherwise if you don't see anything after a couple of years take it as a win.