Mini Split Multi 3 Zone Mitsubishi 20 SEER2 Heat Pump R-454B Condenser, MXZ3D24NL
Three zones, 20 SEER2, and the strongest heating overhead among Mitsubishi's smaller R-454B multis. The MXZ-3D24NL is rated 22,000 BTU/h cooling at 95°F and 25,000 BTU/h heating at 47°F, but reaches a maximum heating output of 30,600 BTU/h — and still delivers up to 21,000 BTU/h at 17°F and 19,800 BTU/h at 5°F. Maximum total connected indoor capacity is 28,000 BTU/h, with 13.70 EER2 and a 10 HSPF2. This is also the first model to open up the full SLZ-AF cassette lineup through 18,000 BTU, so a great room can go flush-ceiling while bedrooms take MSZ-GX wall-mount heads. Piping allows 230 feet total with symmetric 49 foot height limits, and the system is kumo cloud Wi-Fi ready. Add your indoor units below.
Laying Out a Three-Zone Plan
Three zones covers most two-bedroom homes and larger apartments: a living area plus two bedrooms, or a primary suite, guest room, and office. The 28,000 BTU/h connected-capacity ceiling against a 22,000 BTU/h cooling rating gives roughly 27 percent of over-connection to work with, which is what allows a larger living-space unit to coexist with two smaller bedroom units without either compromising.
Format choice is now part of the design rather than an afterthought. A cassette suits rooms where wall space is committed to windows, built-ins, or artwork, and where a dropped ceiling already exists — the four-way discharge also distributes air more evenly across a square room than a single-direction wall head. Wall-mount heads remain simpler and cheaper to install and need no ceiling access. Size each room against its own insulation, glazing, ceiling height, infiltration, and occupancy, then check the set against the compatibility table.
Ideal for: Two-bedroom homes and apartments, a living area plus two bedrooms, primary suite with guest room and office, small duplexes, finished basements with dropped ceilings, and professional suites where a flush cassette in the client-facing room reads better than a wall unit.
Need more capacity? Step up to the 4 Zone Mitsubishi MXZ4D30NL condenser, which adds a fourth zone, raises connected capacity to 36,000 BTU/h, and lifts efficiency to 21 SEER2.
Recommended applications are general guidelines only. Actual system requirements depend on insulation, glazing, ceiling height, ambient conditions, occupancy, and internal heat gain in each zone. Always verify indoor unit selection against the connected-capacity limits on the submittal and the compatibility table in the technical specifications. Request free sizing assistance, contact Budget Heating, or call 813-885-7999.
What's Included
| Outdoor Condenser | MXZ-3D24NL — Multi-Zone Inverter Heat Pump Condenser |
|---|---|
| Indoor Unit Options | Selected Separately Below — MSZ-GX 6K through 18K Wall-Mount or SLZ-AF 9K through 18K Ceiling Cassette |
| Zones Supported | 2 to 3 Indoor Units |
| Rated Capacity | 22,000 BTU/h Cooling @ 95°F / 25,000 BTU/h Heating @ 47°F |
| Maximum Capacity | 22,000 BTU/h Maximum Cooling / 30,600 BTU/h Maximum Heating |
| Max Connected Indoor Capacity | 28,000 BTU/h Total (12,000 BTU/h Minimum) |
| Low-Temperature Heating | 21,000 BTU/h Max @ 17°F / 19,800 BTU/h Max @ 5°F |
| Efficiency | 20 SEER2 / 13.70 EER2 / 10 HSPF2 (Non-Ducted Rating) |
| Maximum Line Length | 230 ft Total / 82 ft to Furthest Indoor Unit / 49 ft Height Difference |
| Refrigerant | R-454B Low-GWP, 5 lb 5 oz Factory Pre-Charge |
| Electrical | 208/230V, Single Phase, 60 Hz — 28.7 A MCA, 25 A Recommended Breaker |
| Controls | Wireless Remote Controller Standard With MSZ-GX Heads; Controller Selected Separately for SLZ Cassettes; kumo cloud Wi-Fi Ready |
| Warranty | 10 Year Manufacturer Warranty |
AHRI certification 216505924 applies to this condenser. The cabinet measures 37-13/32 in. wide x 13 in. deep x 31-11/32 in. high at 137 lb, with sound pressure of 51 dB(A) cooling and 55 dB(A) heating. Maximum overcurrent protection is 48 A. Cooling operates to a 14°F intake and heating to a 6°F intake. The efficiency figures shown are the submittal's non-ducted ratings; separate mixed and ducted columns appear on the sheet, so confirm against your final indoor unit mix.
Condenser & Indoor Unit Features
MXZ-3D24NL Outdoor Condenser
- Maximum heating output of 30,600 BTU/h — 39 percent above cooling rating
- Delivers up to 21,000 BTU/h of heating at 17°F outdoor ambient
- Still reaches 19,800 BTU/h maximum heating at 5°F
- Accepts up to 28,000 BTU/h of total connected indoor capacity
- Serves two or three independently controlled zones
- 20 SEER2 with a strong 13.70 EER2 and a 10 HSPF2
- Low-GWP R-454B refrigerant, 5 lb 5 oz factory pre-charge
- 230 ft total piping with symmetric 49 ft height difference allowance
- Quiet 51 dB(A) cooling sound pressure at 137 lb net
- kumo cloud compatible for app scheduling and remote monitoring
Wall-Mount and Ceiling Cassette Options
- Full SLZ-AF cassette range available — 9K, 12K, 15K and 18K
- MSZ-GX wall-mount heads from 6K through 18K
- Every MSZ-GX head includes a wireless remote controller as standard
- SLP-18FAU grille included with each cassette selection
- Cassettes finish flush in a standard 24" x 24" ceiling grid
- Four-way discharge distributes air evenly across square rooms
- Cassette sound levels start as low as 25 dB(A) on low fan
- Integral drain-up pump lifts condensate up to 33 inches
- Long-life air filter included on the cassettes
- Any mix of wall-mount and cassette across the three zones
Specifications & Manuals
The submittal sheet publishes connected-capacity limits and performance by configuration; the MXZ Multi Technical Specifications carries the Indoor / Outdoor Unit Compatibility Table defining which indoor models may be connected; and the SLZ Technical Specifications, Installation Instructions, Service Manual and Parts List cover the cassettes in full. Read the SLZ Installation Instructions before finalizing a cassette zone — ceiling plenum depth and service access decide whether it is workable.
Frequently Asked Questions
When is a ceiling cassette the better choice over a wall-mount head?
When wall space is committed — windows, built-in cabinetry, artwork — or when the room is roughly square and would benefit from four-way discharge rather than air thrown in one direction. A cassette also disappears visually. The requirements are an accessible dropped ceiling with adequate plenum depth above it.
Is the SLP-18FAU grille an extra purchase?
No. Each cassette option on this page is listed with the SLP-18FAU grille included, so the decorative panel comes with the unit. The grille is required for operation — the cassette cannot be run without it — which is why it is bundled rather than sold as an accessory.
Do cassette zones need a different controller than wall-mount zones?
Yes. MSZ-GX wall-mount heads arrive with a wireless remote controller in the box. SLZ-AF cassettes have no controller included — every option is listed as optional on Mitsubishi's submittal, including handheld wireless kits, wall-mounted wired controllers, and the MHK2 kumo cloud wireless thermostat. Each cassette zone needs one selected.
How quiet are the cassettes compared to the wall units?
Very quiet at low fan. The SLZ-AF09 and AF12 start at 25 dB(A), rising to 31 and 34 dB(A) at high fan respectively; the AF15 runs 27 to 39 dB(A) and the AF18 32 to 43 dB(A). Because a cassette sits overhead rather than at head height, perceived noise is often lower still.
Can I install just two units and add a third later?
Yes. The submittal lists a minimum of two and a maximum of three connected indoor units, so a two-unit configuration is fully supported. The unused connection is capped and can be commissioned when the third room is finished, provided the eventual total stays within the 28,000 BTU/h connected-capacity limit.
Are R-454B systems harder to service than R-410A?
They require different practice rather than more difficulty. R-454B is a mildly flammable A2L refrigerant, so technicians need A2L-rated recovery machines, gauges, and leak detection, and must follow the installation instructions on charge limits and ventilation. Anyone servicing the system should be current on A2L handling.
MXZ-3D24NL Submittal SheetMXZ Technical SpecificationsMXZ Installation InstructionsMXZ Parts ManualMXZ Service ManualMSZ GX Technical SpecificationsMSZ GX Installation InstructionsMSZ GX Operation InstructionsSLZ Technical SpecificationsSLZ Installation InstructionsSLZ Service ManualSLZ Parts ListMSZ GX Parts Manual
