MRCOOL® Signature Series 18K Heat Pump System (Stud Mount) — MCAEAWPEF18D21AA + MCAESHS4T1821AA
Overview
This system pairs the MRCOOL® Signature Series 18K stud mount air handler with the Signature Series 1.5-ton heat pump condenser for year-round heating and cooling. The stud mount air handler is designed to fit between standard wall studs and supports front or bottom return options to match the installation space.
Highlights
- Space-saving stud mount: Designed for between-stud installation where traditional air handlers won’t fit.
- Flexible return air: Air handler supports front or bottom return configurations.
- Efficient airflow: Air handler uses a high-efficiency ECM blower for steady airflow and energy savings.
- All-season performance: Heat pump condenser is listed for heating + cooling, with 5°F minimum ambient heating operation.
- Installer-friendly: Outdoor unit lists sweat connection service valves and an accessible gauge port.
1.5 Ton (18K Class)
14.3 SEER2 • 7.5 HSPF2
3/8" Liquid • 3/4" Suction
5°F Heat • 59°F Cool
Performance varies by climate and installation. Manual J sizing is recommended.
What’s Included
- Stud Mount Air Handler: MCAEAWPEF18D21AA
- Heat Pump Condenser: MCAESHS4T1821AA
- Documentation (see Documents & Downloads)
Indoor Specs
Model: MCAEAWPEF18D21AA (Signature Series Stud Mount Air Handler)
| Unit Type | Air Handler |
| Configuration / Mount | Stud Mount |
| Airflow Direction | Upflow |
| Tonnage | 1.5 Ton |
| Airflow (CFM) | 685 |
| 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 | ECM |
| Blower Motor | 1/3 HP • 5 Speeds • 960 RPM |
| Filter | Replaceable • 15" × 19" × 1" |
| Electrical | 208/230V • 1-Phase • 60 Hz |
| Min Circuit Ampacity (MCA) | 2.5A |
| Max Fuse / Breaker | 3A |
| 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) | 20.5" × 15" × 36" |
| Net Weight | 88 lb |
| GTIN / UPC | GTIN 00840255595919 • UPC 840255595919 |
| 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 Stud Mount Air Handler (MCAEAWPEF18D21AA)
- Signature Series Heat Pump Condenser (MCAESHS4T1821AA)
Important
- Stud mount configuration: Designed to fit between studs; supports front and bottom return air configurations (verify clearances in the install manual).
- Line sizes: Both components list 3/8" liquid and 3/4" suction.
- Line set length: Outdoor unit lists up to 100 ft maximum line set length; verify long-line requirements in the install manual.
- Minimum outdoor temps: Outdoor unit lists 59°F minimum ambient for cooling and 5°F minimum ambient for heating.
- 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, 10 kW) for added cold-weather comfort (sold separately).
FAQs
What is a stud mount air handler?
A stud mount air handler is designed to fit between standard wall studs, helping solve installs where a traditional cabinet won’t fit in a closet/utility space.
Does this system provide heating and cooling?
Yes. The outdoor unit is a heat pump condenser, so the system is listed for heating and cooling.
What refrigerant does it use?
Both components list R-454B.
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.
