This is an indoor slim-duct (concealed duct) unit for a Carrier ductless mini split system โ model 45MBDAQ58XH3, size 58K. It is not a complete system: it requires a matched Carrier outdoor unit, line set, and duct accessories, all sold separately.
The 45MBDAQ58XH3 is Carrier's Performance Ducted Indoor Unit in the 45MBDA family, sized at 58K Btu/h nominal cooling. It's built for concealed installation above a ceiling, in a soffit, or below floor framing, feeding conditioned air through ductwork rather than through a visible wall or cassette head. Carrier publishes AHRI-rated performance for this family, but final system SEER2/HSPF2/EER2 depends entirely on which outdoor unit you pair it with. 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 (This Listing)
- Indoor unit: Carrier 45MBDAQ58XH3 โ Performance Ducted (Slim Duct) indoor unit, size 58K, family 45MBDA
- Outdoor condensing unit: NOT included โ must be selected separately and matched per Carrier's AHRI-certified combinations
- Wireless handheld remote: included per manufacturer overview (temperature-sensing)
Installation Requirements & Accessories
- Voltage: 208/230V; 1Ph; 60Hz
- Refrigerant: R454B (A2L classification), ESTER OIL lubricant
- Liquid line: 3/8 in (9.52 mm); Suction line: 3/4 in (19 mm)
- Standard piping length: 24.6 ft (7.5 m); maximum total piping length: 246 ft (75 m) per manufacturer data
- Line set is SOLD SEPARATELY โ not included with this indoor unit
- Outdoor unit, wall sleeve, duct grille, and mounting/duct accessories are NOT included
- Not compatible as a standalone product โ requires a matched Carrier outdoor unit to function
- Professional installation required โ this is not a DIY/pre-charged kit
Pro-Installer Tip
Concealed duct installs hide flare connections behind a ceiling or soffit, which makes a leak far more expensive to chase down after drywall closes up. Torque every flare fitting to the connection sizes specified for this unit's 3/8 in liquid and 3/4 in suction lines using a calibrated digital torque wrench, and pull a proper vacuum before charging to keep moisture and non-condensables out of an R-454B system. This isn't a job for an uncertified tech: R-454B is a mildly flammable (A2L) refrigerant, and handling it requires EPA Section 608 certification with attention to the A2L-specific leak detection and ventilation practices your local code requires.
Key Benefits
- Concealed duct design keeps the indoor unit out of sight โ no wall or ceiling cassette visible in the room
- Four fan speeds for adjustable airflow control
- Sound levels as low as 22 dBA at the low end of the family's published range
- Compatible with both single-zone and multi-zone Carrier ductless systems
- Uses Puron Advance (R454B) refrigerant, rated for 75% lower global warming potential than legacy refrigerants
- Flexible mounting: ceiling, wall-adjacent, or underfloor setups depending on your ductwork layout
| Spec | Value | Unit |
|---|---|---|
| Component Role | Indoor Slim-Duct (Concealed Duct) Unit | โ |
| Model | 45MBDAQ58XH3 | โ |
| Family | 45MBDA | โ |
| Cooling Rated Capacity (DOE A2 - 95ยฐF) | 54000 | Btu/h |
| Cooling Rated Capacity (DOE B2 - 82ยฐF) | 57500 | Btu/h |
| Heating Rated Capacity (DOE H12 - 47ยฐF) | 60000 | Btu/h |
| Heating Rated Capacity (DOE H32 - 17ยฐF) | 41000 | Btu/h |
| Heating Rated Capacity (ODE H42 - 5ยฐF) | 54000 | Btu/h |
| SEER2 / HSPF2 / EER2 | Dependent on paired outdoor unit | โ |
| Voltage | 208/230; 1Ph; 60 | V; Ph; Hz |
| Breaker Size (MCA/MOCP) | [NEEDS VERIFICATION] | โ |
| Refrigerant Type | R454B | โ |
| Refrigerant Oil | ESTER OIL | โ |
| Liquid Pipe Size | 3/8 (9.52) | in (mm) |
| Suction Pipe Size | 3/4 (19) | in (mm) |
| Standard Piping Length | 24.6 (7.5) | ft (m) |
| Max Total Piping Length | 246 (75) | ft (m) |
| Operating Weight | 230.38 (104.5) | lb (kg) |
| Sound Level (Minimum, family) | 22 | dBA |
| DIY Status | No โ Professional Installation Required | โ |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
Compatibility & Fitment
- Compatible with Carrier's matched, AHRI-certified 45MBDA-family outdoor unit pairings โ confirm exact combination before ordering
- Compatible with dedicated 208/230V, single-phase, 60Hz electrical circuits
- Designed for concealed duct installation (ceiling, wall-adjacent, or underfloor) โ NOT a wall-mounted head or a ceiling cassette
- NOT compatible with 115V-only circuits
- NOT a complete system โ outdoor condenser unit is sold separately and required for operation
- Line set is NOT included โ must be purchased separately in the correct 3/8 in liquid / 3/4 in suction sizing
- Wall sleeve, duct grille, and mounting/duct accessories are NOT included
FAQ
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 classification) refrigerant and requires professional installation. It is a component โ the indoor slim-duct unit only โ and must be matched to a compatible Carrier outdoor unit by a licensed HVAC professional.
Is the line set included, and if not, what size do I need to buy?
The line set is sold separately. This model uses a 3/8 in (9.52 mm) liquid line and a 3/4 in (19 mm) suction line. Standard piping length is 24.6 ft (7.5 m); maximum total piping length is 246 ft (75 m) per manufacturer data. Confirm exact run length needed against your outdoor unit pairing.
What breaker size do I need for this system?
[NEEDS VERIFICATION] โ breaker size (MCA/MOCP) for this specific indoor unit is not stated in the manufacturer data provided. Refer to the installation instructions and electrical data table for the matched outdoor unit.
Does this system work in cold climates (low-ambient heating)?
Heating performance depends on the paired outdoor unit. Manufacturer data for this size class lists a Heating Maximum Capacity at 5ยฐF of 53500 to 54000 Btu/h depending on configuration, but exact low-ambient performance for your specific outdoor pairing should be confirmed against that unit's published data.
Will the ceiling cassette fit between standard 16-inch on-center joists?
This is a concealed slim-duct unit, not a ceiling cassette. Joist-bay fitment specific to 16-inch on-center framing is [NEEDS VERIFICATION] โ manufacturer data does not confirm this dimension for the 58K duct unit.
Compliance & Warranty
Installation by a licensed HVAC professional is required to maintain warranty. This unit uses R-454B (A2L) refrigerant, which requires EPA Section 608 certification to handle. Carrier's Consumer Choice Warranty applies upon timely registration on eligible equipment: choose either a 10-year parts-only limited warranty, or a 5-year parts plus 3-year labor limited warranty. Confirm exact registration terms and eligibility in the manufacturer's warranty documentation.
