This is a Carrier Performance Series 4-way ceiling cassette indoor unit only, size 24K BTU/h, model 45MBCAQ24XA3. It's built for homeowners or contractors assembling a ducted-free zone in a room with a drop ceiling, and it requires a matched Carrier outdoor unit, refrigerant line set, and cassette grille — none of which are included with this listing.
The 45MBCAQ24XA3 is a Carrier Performance Series indoor cassette, part of the 45MBCA family, designed to mount into a drop ceiling as a traditional 4-way cassette rather than a slim one-way unit built for joist bays. It ships without a grille — the decorative panel is a separate purchase — and it is only rated as a complete system once matched with an AHRI-certified Carrier outdoor unit. Note: If you would like to review the manufacturer Product Specifications, Warranty, Brochure, etc., for this system, please refer to the "Resources (System Manuals and Warranty)" Tab above on this page.
System Components
- Indoor Unit: Carrier Performance Cassette 45MBCAQ24XA3 — 24K BTU/h 4-way ceiling cassette, this listing only
- Outdoor Condenser: Sold separately — must be an AHRI-certified match; specific model [NEEDS VERIFICATION]
- Cassette Grille/Decorative Panel: Sold separately, not included
- Wireless remote controller: Included with this indoor unit
Installation Requirements & Accessories
- Voltage: 208/230V; 1Ph; 60Hz (system-level power supply per manufacturer data)
- Refrigerant: R-454B (Puron Advance), ESTER OIL — professional handling required
- Line set size: Depends on paired outdoor unit — [NEEDS VERIFICATION] for this exact size-24 pairing
- Line Set Sold Separately — not included with this indoor unit
- Not Included: outdoor condenser, cassette grille/panel, ceiling mounting sleeve, line set
- Not Compatible With: 115V-only circuits; non-AHRI-matched outdoor unit families
- Professional installation required — this is not a DIY/pre-charged system
Pro-Installer Tip
Flare connections on cassette liquid and suction lines are a common point of long-term refrigerant loss if the flare is under- or over-torqued. Loose flares slowly bleed R-454B charge, showing up months later as poor cooling or a communication/protection fault at the outdoor unit. Torque each flare nut to the fitting manufacturer's spec using a calibrated digital torque wrench, and pull the system into a proper vacuum before charging. Under EPA Section 608 rules, only certified technicians may handle A2L refrigerants like R-454B — factor this into scheduling and labor cost when quoting the job.
Key Benefits
- Sound levels as low as 23.5 dBA at the indoor unit for quiet occupied-space operation
- Four fan-speed settings with Follow Me temperature sensing and adjustable air direction
- No ductwork required — installs without ceiling tear-out, patching, or repainting
- Compatible with single-zone and multi-zone Carrier ductless configurations
- Uses Puron Advance (R-454B) refrigerant, rated to reduce global warming potential by 75% versus older refrigerants
- Wireless remote controller included
| Spec | Value | Unit |
|---|---|---|
| Indoor Unit Architecture | Traditional 4-Way Ceiling Cassette | — |
| Model | 45MBCAQ24XA3 | — |
| Cooling Rated Capacity (DOE A2 - 95°F) | 23400 | Btu/h |
| Cooling Rated Capacity (DOE B2 - 82°F) | 24400 | Btu/h |
| Heating Rated Capacity (DOE H12 - 47°F) | 25000 | Btu/h |
| Heating Rated Capacity (DOE H32 - 17°F) | 20400 | Btu/h |
| Heating Rated Capacity (DOE H42 - 5°F) | 23800 | Btu/h |
| SEER2 | Dependent on paired outdoor unit | — |
| HSPF2 | Dependent on paired outdoor unit | — |
| EER2 | Dependent on paired outdoor unit | — |
| Power Supply | 208/230V;1Ph;60Hz | V;Ph;Hz |
| Sound Level (as low as) | 23.5 | dBA |
| Refrigerant Type | R-454B (Puron Advance) | — |
| Refrigerant Oil | ESTER OIL | — |
| Line Set Size | [NEEDS VERIFICATION] | — |
| Operating Range (Cooling) | -22 to 122 (-30 to 55) | °F (°C) |
| Breaker Size (MCA/MOP) | [NEEDS VERIFICATION] | A |
| DIY Status | No — Professional Installation Required | — |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
- Fits: Drop/suspended ceiling installations designed for a traditional 4-way cassette layout
- Compatible with 208/230V single-phase circuits per manufacturer power supply data
- Must be paired with an AHRI-certified Carrier outdoor unit — specific matched model [NEEDS VERIFICATION]
- Not compatible with 115V-only circuits
- Not included: outdoor condenser, line set, cassette grille/decorative panel, ceiling mounting sleeve
- Not a slim one-way cassette — not engineered to fit into standard 16-inch on-center joist bays
FAQ
What breaker size do I need for this system?
Breaker sizing (MCA/MOP) depends on the outdoor unit this indoor cassette is paired with. [NEEDS VERIFICATION] for the specific outdoor unit pairing — refer to the matched outdoor unit's data plate and the "Resources (System Manuals and Warranty)" Tab above.
Is professional installation required to keep the warranty valid, or is this a true DIY kit?
This is not a DIY kit. It uses R-454B (A2L) refrigerant and requires professional installation by a licensed HVAC contractor.
Is the line set included, and if not, what size do I need to buy?
The line set is not included and is sold separately. Exact liquid and suction line sizes for this indoor unit depend on the paired outdoor unit model — [NEEDS VERIFICATION] for the specific pairing. Refer to the matched outdoor unit's piping specifications.
Will the ceiling cassette fit between standard 16-inch on-center joists?
This is a traditional 4-way cassette designed for a drop/suspended ceiling installation, not a slim one-way cassette engineered for standard 16-inch on-center joist bays. Cassette dimensions for this specific model are [NEEDS VERIFICATION].
Does this system work in cold climates (low-ambient heating)?
Heating performance in cold weather depends on the paired outdoor unit's low-ambient heating capability. This indoor unit does not determine that rating on its own — [NEEDS VERIFICATION] for a specific outdoor pairing.
Compliance & Warranty
Installation by a licensed HVAC professional is required to maintain warranty. This unit uses R-454B (A2L) refrigerant, and handling/charging must be performed under EPA Section 608 certification. Under Carrier's Consumer Choice Warranty, upon timely registration, eligible equipment qualifies for either a 10-year parts-only limited warranty or a 5-year parts plus 3-year labor limited warranty. Full terms are in the manufacturer warranty documentation — see the "Resources (System Manuals and Warranty)" Tab above.
