MRCOOL® Signature Series 42K (3.5 Ton) Heat Pump System — MCAEAMPEF42C21AA + MCAESHS4T4221AA
Overview
The MRCOOL® Signature Series 42K heat pump system pairs a multi-position air handler with a split-system heat pump condenser for year-round heating and cooling. The outdoor unit provides heating and cooling, while the air handler supports upflow, downflow, and horizontal installations and uses an efficient ECM blower (5 speeds). Both components use R-454B refrigerant.
Highlights
- All-season system: Heat pump condenser listed for heating + cooling.
- Efficiency ratings: Outdoor unit listed at 14.3 SEER2, 11.7 EER2, and 7.5 HSPF2.
- Flexible placement: Air handler supports upflow, downflow, and horizontal configurations.
- Quiet-minded design: Outdoor sound listed as 65 dB(A); indoor sound listed as 54 dB(A).
- Cold-weather note: Outdoor unit lists 5°F minimum ambient heating operation.
3.5 Ton (42K Class)
14.3 SEER2 • 7.5 HSPF2
3/8" Liquid • 3/4" Suction
Up to 150 ft
Performance varies by climate and installation. Manual J sizing is recommended.
What’s Included
- Multi-Position Air Handler: MCAEAMPEF42C21AA
- Heat Pump Condenser: MCAESHS4T4221AA
- Documentation (see Documents & Downloads)
Indoor Specs
Model: MCAEAMPEF42C21AA (Signature Series Multi-Position Air Handler)
| Unit Type | Air Handler |
| Configuration / Mount | Multi-Position (Upflow / Downflow / Horizontal) |
| Tonnage | 3.5 Ton |
| Airflow (CFM) | 1254 |
| Sound | 54 dB(A) |
| Refrigerant | R-454B |
| Metering Device | Orifice |
| Drain Connection Size | 3/4" |
| Line Sizes | Liquid 3/8" • Suction 3/4" |
| Blower Motor Type | ECM |
| Blower Motor | 3/4 HP • 5 Speeds • 1040 RPM |
| Filter | Replaceable • 18" × 21" × 1" |
| Electrical | 208/230V • 1-Phase • 60 Hz |
| Min Circuit Ampacity (MCA) | 7.2A |
| Max Fuse / Breaker | 10A |
| Aux Heat | Not included • Optional heat kit available (5 kW, 7.5 kW, 10 kW) |
| Certifications | UL Listed • CSA Listed • ETL Listed • AHRI Certified |
| Color | Grey |
| Dimensions (W×D×H) | 19.625" × 22" × 45.75" |
| Net Weight | 131 lb |
| GTIN / UPC | GTIN 00840255595889 • UPC 840255595889 |
| Proposition 65 | Yes |
Designed to work with Signature Series top discharge condensers.
Outdoor Specs
Model: MCAESHS4T4221AA (Signature Series Split System Heat Pump Condenser)
| Unit Type | Split System Heat Pump Condenser |
| Tonnage | 3.5 Ton |
| Cooling / Heating Capacity | 39,000 BTU / 39,000 BTU |
| Efficiency | 14.3 SEER2 • 11.7 EER2 • 7.5 HSPF2 |
| Airflow (CFM) | 2950 |
| Sound | 65 dB(A) |
| Inverter | No |
| Min Ambient (Cooling) | 59°F |
| Min Ambient (Heating) | 5°F |
| Refrigerant | R-454B • 119.9 oz |
| Max Line Set Length | 150 ft |
| Line Sizes | Liquid 3/8" • Suction 3/4" |
| Compressor | Scroll |
| Condenser Fan Motor | PSC • 1/7 HP |
| Electrical | 208/230V • 1-Phase • 60 Hz |
| Min Circuit Ampacity (MCA) | 26A |
| Max Fuse / Breaker | 45A |
| Certifications | UL Listed • CSA Listed • ETL Listed • AHRI Certified |
| Color | Grey |
| Dimensions (W×D×H) | 29.14" × 29.14" × 32.875" |
| Net Weight | 202 lb |
| GTIN / UPC | GTIN 00840255595810 • UPC 840255595810 |
| Proposition 65 | Yes |
Designed to work with Signature Series Multi-Position or Stud Mount air handlers.
Documents & Downloads
- Signature Series Multi-Position Air Handler (MCAEAMPEF42C21AA)
- Signature Series Heat Pump Condenser (MCAESHS4T4221AA)
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 150 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, 7.5 kW, and 10 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.
