
MRCOOL® Signature Series 42K (3.5 Ton) Heat Pump System — MCAEAMPEF42C21AA + MCAESHS4T4221AA
Overview
TheMRCOOL® Signature Series 42Kheat pump system pairs amulti-position air handlerwith asplit-system heat pump condenserfor year-round heating and cooling. The outdoor unit providesheating and cooling, while the air handler supportsupflow, downflow, and horizontalinstallations and uses an efficientECM blower(5 speeds). Both components useR-454B refrigerant.
Highlights
- All-season system:Heat pump condenser listed forheating + cooling.
- Efficiency ratings:Outdoor unit listed at14.3 SEER2,11.7 EER2, and7.5 HSPF2.
- Flexible placement:Air handler supportsupflow, downflow, and horizontalconfigurations.
- Quiet-minded design:Outdoor sound listed as65 dB(A); indoor sound listed as54 dB(A).
- Cold-weather note:Outdoor unit lists5°Fminimum 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 withSignature 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 withSignature Series Multi-PositionorStud Mountair handlers.
Documents & Downloads
- Signature Series Multi-Position Air Handler (MCAEAMPEF42C21AA)
- Brochure (EN)
- Installation & User Manual (EN)
- Warranty (EN)
- Signature Series Heat Pump Condenser (MCAESHS4T4221AA)
- Brochure (EN)
- Installation & User Manual (EN)
- Warranty (EN)
- AHRI Certificate (PDF)
- EnergyGuide (PDF)
Important
- Heat pump operation:This pairing includes aheat pump condenserforheating + cooling.
- Minimum outdoor temps:Outdoor unit lists59°Fminimum ambient for cooling and5°Fminimum ambient for heating.
- Line sizes:Listed as3/8" liquidand3/4" suction; confirm routing and any long-line requirements in the installation manual.
- Line set length:Outdoor unit lists up to150 ftmaximum line set length; verify long-line accessories/requirements in the install manual.
- Electrical:Both components are208/230V, 1-phase, 60 Hz. Verify breaker/fuse sizing per install manual and local code.
- Aux heat option:Air handler supports optional heat kits (listed as5 kW,7.5 kW, and10 kW) for added cold-weather comfort (sold separately).
FAQs
Does this system provide heating and cooling?
Yes. The outdoor unit is aheat pump condenser, so the system is listed forboth heating and cooling.
What installation positions does the air handler support?
The air handler ismulti-positionand supportsupflow, downflow, and horizontalconfigurations.
What refrigerant and line sizes does it use?
Refrigerant is listed asR-454B. Line sizes are3/8" liquidand3/4" suction.
How cold can it run in heating?
The outdoor unit lists a minimum ambient heating temperature of5°F.
What warranty coverage is included?
Warranty is listed as10-year limited parts, withlimited compressorcoverage referenced for the outdoor unit.






















































































