MRCOOL DIYCASSETTE18HP-230D25-O + DIY-18-HP-C-230D25-O – DIY 5th Gen OuttaSight 18K BTU 230V Complete Single-Zone Ceiling Cassette System with 25 ft Lineset

MRCOOL® DIY® 5th Gen OuttaSight™ 18,000 BTU Complete Single-Zone Ceiling Cassette System

This is a complete single-zone heat pump system: the MRCOOL® DIY® 5th Generation OuttaSight™ 18K BTU ceiling cassette (DIYCASSETTE18HP-230D25-O) matched to its factory-certified 230V outdoor condenser (DIY-18-HP-C-230D25-O). The 25 ft. pre-charged DIY® lineset ships inside the condenser carton, so everything needed for a single-zone installation arrives together.

What is in the box

• (1) DIYCASSETTE18HP-230D25-O — DIY® 5th Gen OuttaSight™ 18,000 BTU 230V ceiling cassette air handler with remote control
• (1) DIY-18-HP-C-230D25-O — DIY® 5th Gen 18,000 BTU 230V outdoor condenser
• (1) 25 ft. pre-charged DIY® lineset, included in the condenser carton

Product details

The OuttaSight™ Ceiling Cassette delivers efficient heating and cooling while staying discreet and out of sight. It is pre-charged with R-454B refrigerant and rated at 21 SEER2, covering roughly 700–1,000 sq. ft.

• Low profile installation — a recessed ceiling profile that disappears into the room instead of taking wall space.
• New construction or retrofit — designed to recess between all common joist types on 16 in. centers, including pre-manufactured I-joists.
• No-vacuum DIY® lineset — the pre-charged quick-connect lineset means no vacuum pump and no refrigerant handling during installation.
• Smart control — set schedules and temperature parameters and manage the system from your phone with the MRCOOL® Smart HVAC app.
• Warranty — as a matched 5th Generation cassette-and-condenser pair this system qualifies for MRCOOL®’s optional limited lifetime compressor warranty, 7-year compressor replacement, and 5-year parts warranty for the original registered owner. Registration rules and restrictions apply.

Certified single-zone pairings

MRCOOL® certifies the 18K OuttaSight™ cassette for single-zone use with DIY-18-HP-C-230D25-O (supplied here) and with DIYHH-18-HP-C-230D25-O Hyper Heat. Both condensers include the 25 ft. lineset. The 6K and 9K OuttaSight™ cassettes have no single-zone option and must be installed on a multi-zone condenser.

Building a multi-zone system instead?

This cassette can also run as one zone on a DIY® 5th Gen multi-zone condenser (DIY-MULTI3-18HP230D-O, DIY-MULTI4-27HP230D-O, DIY-MULTI5-36HP230D-O, DIY-MULTI6-48HP230D-O, or DIY-MULTI6-55HP230D-O). Multi-zone condensers do not include linesets — each zone needs its own DIY® lineset purchased separately. Order the cassette on its own if you are going that route.

Why buy from Cedars HVAC

• Genuine OEM MRCOOL® equipment — never aftermarket substitutes
• Matched, factory-certified pairings so your warranty stays intact
• Fast nationwide shipping direct from the distribution center
• Real HVAC expertise — our team confirms compatibility before you order
• Financing available at checkout

Shipping and returns

Most orders ship within 6–8 business days. Standard ground shipping covers the continental United States, and expedited options are available at checkout. Returns are accepted within 30 days on unopened, uninstalled equipment — see our return policy for full details. International shipping is available on request.

Frequently asked questions

Does this include the lineset? Yes. The 25 ft. pre-charged DIY® lineset ships inside the DIY-18-HP-C-230D25-O condenser carton. No separate lineset purchase is needed for this single-zone system.

Do I need an HVAC technician to install it? The DIY® series is designed for owner installation with pre-charged quick-connect linesets and no refrigerant handling. Electrical connections should still follow local code, and some jurisdictions require a licensed electrician or permit.

Can I add more zones later? Not to this condenser — DIY-18-HP-C-230D25-O is single-zone. Adding zones later means moving to a DIY® multi-zone condenser.

Can I get a contractor or wholesale discount? Yes. Cedars HVAC offers volume pricing for licensed HVAC contractors, property managers, and resellers. Request contractor pricing to set up an account.

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Line set sizing

Confirmed with MRCOOL: the 18,000 BTU OuttaSight cassette uses a 1/4″ liquid × 1/2″ suction line set. Do not order a 1/4″ × 3/8″ set for this air handler. Correct R-454B line sets are listed as recommended add-ons on this page.