MRCOOL
The MRCOOL DIY 5th Gen 12K is the leading homeowner-installable single-zone ductless heat pump, rated 23.5 SEER2 / 12.5 EER2 / 10.2 HSPF2 on low-GWP R-454B. Its pre-charged QuickConnect line set lets a DIYer install it without an EPA refrigerant license.
$1,880
Live price at SylvanePrice checked Sep 24, 2026
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Will it cool your room?
This unit's cooling matches a 549 sq ft room. Set your room size to check the fit for your space.
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.
At a glance
Best for diy whole-room heating and cooling up to about 550 sq ft.
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.
Plug and play
R-454B
Compare splits against the other types on price, noise, efficiency and install.
The questions buyers ask, answered from live prices and real specs. See where a split like this fits.
Editor's pickSenville
The Senville LETO 12K (115V) is a budget single-zone inverter heat pump rated 21.2 SEER2 on R-454B, with quiet 17.5 dB minimum indoor noise and built-in WiFi. It suits rooms of roughly 450 to 750 sq ft.
$800
Hardware price
+ pro install, usually $1,500-4,000
Senville
A wall-mounted split air conditioner rated at 9,000 BTU for rooms up to 400 sq ft. It heats in winter too.
Pioneer
A wall-mounted split air conditioner rated at 11,500 BTU for rooms up to 500 sq ft. It heats in winter too.
$729
at Sylvane
+ pro install, usually $1,500-4,000
$664
at Sylvane
+ pro install, usually $1,500-4,000