How energy-efficient is the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V?

Its efficiency rating is SEER2 19.

Do I need a professional to install the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V?

Yes. As a single split it needs a certified installer. Usually needs permission.

Single splitSEER2 19 Heats too

Pioneer · Model WYT009ALSI20RL

Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V

Name: Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V
Brand: Pioneer
Price: 858 USD
Availability: InStock

A wall-mounted split air conditioner rated at 9,000 BTU for rooms up to 350 sq ft. It heats in winter too.

$858

Live price at Sylvane

Price checked Oct 1, 2026

Buy at Sylvane In stock

compare.ac may earn a commission on purchases, at no cost to you. It never changes the price you pay or how we rank units.

Will it cool your room?

Room size (assumed)350 sq ft ≈ 32.5 m²

Fits a 32.5 m² room

This unit's cooling matches a 350 sq ft room. Set your room size to check the fit for your space.

Running cost

Mini-splits are rated on SEER2, a seasonal scale, not the ENERGY STAR annual-kWh figure this dollar estimate is built from, so there is no comparable figure to show here. A blank is missing data, not a worse result: a mini-split is often the more efficient choice.

Installation cost

$2,500-6,000 fully installed for a typical room (the equipment is roughly $700-1,800, professional installation roughly $1,500-4,000+ depending on line-set run, electrical and access). The unit price you see here is hardware only; installation is the larger, separate cost.

A typical range for this system type, for comparison only, not a quote for this unit. The actual price depends on the line-set run, electrical work and access.

At a glance

Best for year-round use, cooling in summer and heating in winter.

Cooling

2.6 kW

Size

Slim

Noise

54 dB

Audible

Install: Certified installerPermission: Usually needs permission

Performance

Cooling capacity: 9,000 BTU · 2.6 kW
Heating capacity: 10,000 BTU
Heats down to: -4°F outdoors
Room coverage: up to 350 sq ft
Energy Star: Not published
SEER2: 19
EER2: 11.7
Annual energy (cooling): Not published

Noise, size & features

Model number: WYT009ALSI20RL
Indoor noise: 54 dB(A)about as loud as a dishwasher
Outdoor noise: Not published
Indoor unit: 31.88 x 11.5 x 8 in
Outdoor unit: 31 x 19.38 x 11.5 in (W x H x D)
Refrigerant: R-454B
Wi-Fi / app: Not published
Outdoor unit needed: Yes
Warranty: 5-Year Limited Warranty

EER2, SEER2, warranty, heating capacity, refrigerant, heating limit and outdoor unit size are from Sylvane's published specifications for this exact configuration, checked Sep 26, 2026.

What is good

At $858 it undercuts 13 of the 16 other 8,000-9,000 BTU mini-splits we list with a live price.
Uses R-454B (GWP 466), the low-GWP class new US residential equipment moved to.

Installation & the rules that apply

This is a single split. This is where regulation bites. Under EPA Section 608 the refrigerant circuit may only be opened by a certified technician, and the EPA is explicit that this includes connecting or disconnecting the pre-charged line sets sold with "DIY" mini-split kits. No federal law stops you doing the mounting, bracketing and line routing yourself, but handling the refrigerant without certification voids the warranty and is a violation. Most US jurisdictions also require permits for a new outdoor unit: typically mechanical or building for the wall penetration and mount, plus electrical for the dedicated 240 V circuit and disconnect. An HOA nearly always has to approve exterior equipment in advance, and local noise ordinances can cap how loud the condenser may be at the property line. This varies by city and county, so confirm with your building department before buying hardware.

Installation

Certified installer

Refrigerant

R-454B

GeneralRenters: get written landlord consent firstReviewed June 2026Often blocks install

United StatesUS: EPA Section 608 certified technician for refrigerantReviewed June 2026Often blocks install

ArizonaArizona: municipal mechanical permit for AC replacementReviewed June 2026Permit required

CaliforniaCalifornia: Title 24 permit and HERS verificationReviewed June 2026Permit required

FloridaFlorida: hurricane wind-load anchoring of outdoor unitsReviewed June 2026Permit required

See full rules by region

Common questions about the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V

How loud is the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V?: 54 dB(A) indoors, about as loud as a dishwasher.
How energy-efficient is the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V?: Its efficiency rating is SEER2 19.
What size room does the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V cool?: It is rated to cool a room up to 350 sq ft (9,000 BTU · 2.6 kW).
Do I need a professional to install the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V?: Yes. As a single split it needs a certified installer. Usually needs permission.
Does the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V heat as well as cool?: Yes. It also heats, rated 10,000 BTU of heating output.
How cold can it get outside before the Pioneer Diamante Pro 9,000 BTU High-Wall Ductless Mini Split 115V stops heating?: Its retailer's specification for this exact configuration rates it to keep heating down to -4°F outdoors. That is its operating limit, not its full output: a heat pump delivers less heat as it gets colder, so size it for your coldest days.