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Head-to-head · Best Mini Split Air Conditioners

Della Optima Series 12,000 BTU 115V vs Senville LETO 9,000 BTU 115V (SENL-09CD-16)

Which is the better buy? Side-by-side on rating, price, strengths, and watch-outs — with the published ratings we averaged to get there.

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The short answer

Senville LETO 9,000 BTU 115V (SENL-09CD-16) comes out ahead by a clear margin (4.0 vs 3.3). Senville LETO 9,000 BTU 115V (SENL-09CD-16) is best for: Handy owners cooling or heating a single room on a 115V circuit who own, or are willing to buy, a vacuum pump, gauges and a flaring tool. Read the strengths below before deciding.

Della Optima Series 12,000 BTU 115V
Ranked #3 in Best Mini Split Air Conditioners
Della Optima Series 12,000 BTU 115V
1 source$969.96as of Oct 14

The Della Optima Series 12,000 BTU is a 115-volt, 23 SEER2 heat pump mini split with Wi-Fi app control, listed by Della for spaces up to 550 square feet. Wired rated it 6 out of 10: its reviewer found it cooled and heated the room well, ran quietly and had a capable app with Alexa and Google Assistant support, but could never get the geofencing feature to work and was quoted $3,600 for professional installation, several times the price of the hardware.

Strengths
  • — Wired found it kept the room properly cooled and heated after a professional install
  • — Quiet in Wired's measurements: 50 dB on turbo and 40 dB on night mode at 3 feet, against 30 dB of ambient sound
  • — Runs on a 115-volt circuit with a 960-watt maximum draw, per Wired
Watch-outs
  • — Geofencing never worked for Wired, even after 10 days of troubleshooting with Della support
  • — Wired was quoted $3,600 for professional installation, far more than the unit itself
  • — The 15-button infrared remote is complex and needs line of sight; Wired notes commands are ignored if it is not aimed at the air handler
$969.96 · Check Price on AmazonFull review →
Senville LETO 9,000 BTU 115V (SENL-09CD-16)
Higher ratedRanked #2 in Best Mini Split Air Conditioners
Senville LETO 9,000 BTU 115V (SENL-09CD-16)
1 sourceall derived$699.99as of Oct 16

The Senville LETO SENL-09CD-16 is a 9,000 BTU ductless mini-split heat pump that runs on a 115V circuit. In a video review after about three weeks of use in his kitchen, Fix It Scotty called it very quiet, inside and out, and economical, and said it would be a win overall if it lasts. The catch is installation: he describes it as a job for a fairly advanced DIYer, because the line set has to be cut, re-flared and vacuumed down with a pump before the refrigerant is released.

Strengths
  • — Very quiet indoors, and Fix It Scotty says the outdoor unit is about as quiet, without the usual compressor grind
  • — Economical: Fix It Scotty cites a $699 retail price for the unit and put his total at under $800, as he already owned the tools
  • — Runs on a 115V, 15-amp dedicated circuit in the 9,000 BTU size, per Fix It Scotty
Watch-outs
  • — Installation needs a fairly advanced DIYer: Fix It Scotty had to trim and re-flare the line set, then vacuum it down with a pump and check for leaks with a gauge set before releasing refrigerant
  • — A dedicated circuit and outdoor disconnect are needed; Fix It Scotty suggests an electrician if you are not comfortable working in your panel
  • — Line set cover and outdoor wall bracket are not included; Fix It Scotty bought both separately
$699.99 · Check Price on AmazonFull review →

Derived means the reviewer published no score, so one was inferred from their written verdict. Everything else is a number the publisher printed. How we rank.

How they stack up

Della Optima Series 12,000 BTU 115V

The Della Optima and the Senville LETO 9,000 BTU are the two 115V units on this page; the LG Artcool Deluxe KNSAL needs 208/230V. Its 12,000 BTU of cooling equals the LG and is above the Senville's 9,000 BTU. Wired lists 12,400 BTU of heating for it, under the LG's 13,000 BTU. It uses R454B refrigerant like the Senville, where the LG uses R-32.

Senville LETO 9,000 BTU 115V (SENL-09CD-16)

Like the Della Optima Series 12,000 BTU 115V, the LETO runs on a 115V circuit, but it is a smaller 9,000 BTU unit, and its listing rates the heat pump to 5F against the LG Artcool Deluxe KNSAL's full heating capacity at -13F. Unlike the Della, which Wired had professionally installed, the LETO's hands-on source installed it himself, line set vacuum included.

Specs side-by-side

SpecDella Optima Series 12,000 BTU 115VSenville LETO 9,000 BTU 115V (SENL-09CD-16)
Cooling Capacity12,000 BTU9,000 BTU
Heating Capacity12,400 BTU—
Efficiency23 SEER221.5 SEER2 (listing)
Voltage115V115V, 60Hz, 1Ph
RefrigerantR454BR-454B
Rated Coverage550 sq ft—
Maximum Power Draw960 watts—
TypeWall-mount ductless heat pump—
Heat Pump—Yes, rated to work down to 5F (listing)
Indoor Noise—25 dB (listing)
Line Set—16 ft included
Warranty—5 years parts, 5 years compressor, labor not included (listing)
Model—SENL-09CD-16
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