MRCOOL® Signature Series 18K (1.5 Ton) Heat Pump System — MCAEAMPSF18C21AA + MCAESHS4T1821AA
Overview
The MRCOOL® Signature Series 18K heat pump system pairs a multi-position air handler with a split-system heat pump condenser for year-round comfort. The outdoor unit provides both heating and cooling, while the air handler supports upflow, downflow, and horizontal installations for flexible placement in closets, attics, or crawl spaces. Both components use R-454B refrigerant.
Highlights
- Year-round comfort: Heat pump provides heating + cooling from one outdoor unit.
- Efficient ratings: Outdoor unit listed at 14.3 SEER2, 11.7 EER2, and 7.5 HSPF2.
- Flexible install: Air handler supports upflow, downflow, and horizontal configurations.
- Modern refrigerant: System uses R-454B.
- Cold-weather note: Outdoor unit lists 5°F minimum ambient heating operation.
1.5 Ton (18K Class)
14.3 SEER2 • 7.5 HSPF2
3/8" Liquid • 3/4" Suction
59°F Cool • 5°F Heat
Performance varies by climate and installation. Manual J sizing is recommended.
What’s Included
- Multi-Position Air Handler: MCAEAMPSF18C21AA
- Heat Pump Condenser: MCAESHS4T1821AA
- Documentation (see Documents & Downloads)
Indoor Specs
Model: MCAEAMPSF18C21AA (Signature Series Multi-Position Air Handler)
| Unit Type | Air Handler |
| Configuration / Mount | Multi-Position (Upflow / Downflow / Horizontal) |
| Tonnage | 1.5 Ton |
| Airflow (CFM) | 749 |
| Sound | 53 dB(A) |
| Refrigerant | R-454B |
| Metering Device | Orifice |
| Drain Connection Size | 3/4" |
| Line Sizes | Liquid 3/8" • Suction 3/4" |
| Blower Motor Type | PSC |
| Blower Motor | 1/4 HP • 3 Speeds • 830 RPM |
| Filter | Replaceable • 18" × 21" × 1" |
| Electrical | 208/230V • 1-Phase • 60 Hz |
| Min Circuit Ampacity (MCA) | 2.1A |
| Max Fuse / Breaker | 3A |
| Aux Heat | Not included • Optional heat kit available (5 kW, 7.5 kW) |
| Certifications | UL Listed • CSA Listed • ETL Listed • AHRI Certified |
| Color | Grey |
| Dimensions (W×D×H) | 19.625" × 22" × 45.75" |
| Net Weight | 120 lb |
| GTIN / UPC | GTIN 00840255595841 • UPC 840255595841 |
| Proposition 65 | Yes |
Designed to work with Signature Series top discharge condensers.
Outdoor Specs
Model: MCAESHS4T1821AA (Signature Series Split System Heat Pump Condenser)
| Unit Type | Split System Heat Pump Condenser |
| Tonnage | 1.5 Ton |
| Cooling / Heating Capacity | 17,000 BTU / 17,000 BTU |
| Efficiency | 14.3 SEER2 • 11.7 EER2 • 7.5 HSPF2 |
| Airflow (CFM) | 1950 |
| Sound | 60 dB(A) |
| Inverter | No |
| Min Ambient (Cooling) | 59°F |
| Min Ambient (Heating) | 5°F |
| Refrigerant | R-454B • 81.1 oz |
| Max Line Set Length | 100 ft |
| Line Sizes | Liquid 3/8" • Suction 3/4" |
| Compressor | Scroll |
| Condenser Fan Motor | PSC • 1/9 HP |
| Electrical | 208/230V • 1-Phase • 60 Hz |
| Min Circuit Ampacity (MCA) | 12.2A |
| Max Fuse / Breaker | 20A |
| Certifications | UL Listed • CSA Listed • ETL Listed • AHRI Certified |
| Color | Grey |
| Dimensions (W×D×H) | 23.6" × 23.6" × 25" |
| Net Weight | 144 lb |
| GTIN / UPC | GTIN 00840255595773 • UPC 840255595773 |
| Proposition 65 | Yes |
Designed to work with Signature Series Multi-Position or Stud Mount air handlers.
Documents & Downloads
- Signature Series Multi-Position Air Handler (MCAEAMPSF18C21AA)
- Signature Series Heat Pump Condenser (MCAESHS4T1821AA)
Important
- Heat pump operation: This pairing includes a heat pump condenser for heating + cooling.
- Minimum outdoor temps: Outdoor unit lists 59°F minimum ambient for cooling and 5°F minimum ambient for heating.
- Line sizes: Listed as 3/8" liquid and 3/4" suction; confirm routing and any long-line requirements in the installation manual.
- Line set length: Outdoor unit lists up to 100 ft maximum line set length; verify long-line accessories/requirements in the install manual.
- Electrical: Both components are 208/230V, 1-phase, 60 Hz. Verify breaker/fuse sizing per install manual and local code.
- Aux heat option: Air handler supports optional heat kits (listed as 5 kW and 7.5 kW) for added cold-weather comfort (sold separately).
FAQs
Does this system provide heating and cooling?
Yes. The outdoor unit is a heat pump condenser, so the system is listed for both heating and cooling.
What installation positions does the air handler support?
The air handler is multi-position and supports upflow, downflow, and horizontal configurations.
What refrigerant and line sizes does it use?
Refrigerant is listed as R-454B. Line sizes are 3/8" liquid and 3/4" suction.
How cold can it run in heating?
The outdoor unit lists a minimum ambient heating temperature of 5°F.
What warranty coverage is included?
Warranty is listed as 10-year limited parts, with limited lifetime compressor coverage referenced for the outdoor unit.
