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)
- Brochure (EN)
- Installation & User Manual (EN)
- Warranty (EN)
- Signature Series Heat Pump Condenser (MCAESHS4T1821AA)
- Brochure (EN)
- Installation & User Manual (EN)
- Warranty (EN)
- AHRI Certificate (PDF)
- EnergyGuide (PDF)
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.
Loading accessories…
We will prepare your order within 24 hours if it’s received on a weekday (before noon). Orders are shipped in one to two business days. Transit time is between 3 to 6 business days, although exceptions apply. We email tracking information once your purchase is shipped.
Delivery Map
IMPORTANT DELIVERY INFORMATION: Please be kindly informed that this air conditioner, due to its weight and shipping restrictions, is shipped palletized with an arranged freight service and requires an appointment for delivery. To AVOID delays, please check if the provided phone number in the order details is a current number where you can be reached. You can also contact the carrier directly and refer to your tracking number to set up a date and time for your appointment. It is your responsibility to ensure a safe and secure environment for delivery. Please note that we cannot be held liable for any packages that are stolen or lost after delivery has been confirmed. PLEASE verify your shipping address, as changes to the address after freight has shipped can result in an additional 15% or higher fee depending on freight weight and dimensions.
SMALLWARES INFORMATION: Please be informed that for smaller items, such as Installation Kits, Smart Connectivity Dongles, and TTW Sleeves, when these items are ordered individually, they may be shipped via FedEx without a signature requirement. It is your responsibility to ensure a safe and secure environment for delivery. Please note that we cannot be held liable for any packages that are stolen or lost after delivery has been confirmed. Thank you for your understanding and cooperation.
INSPECT YOUR MERCHANDISE BEFORE SIGNING: Please inspect your boxes thoroughly when you receive them. They should arrive shrink-wrapped and on a pallet. If you notice any damages or imperfections (e.g. crushed box or forklift hole), please write comments on the receipt before signing for delivery, no matter how small damages seem. Contact us immediately to assist you.
Shipping & Delivery
We will prepare your order within 24–48 hours if it’s received on a weekday (before noon). Orders are shipped in one to two business days. Transit time is between 3 to 6 business days, although exceptions apply. We email tracking information once your purchase is shipped.
Delivery Map
IMPORTANT DELIVERY INFORMATION
Please be informed that this air conditioner, due to its weight and shipping restrictions, is shipped palletized with an arranged freight service and requires an appointment for delivery.
To AVOID delays, please make sure the phone number in your order details is accurate and one where you can be reached. You may also contact the carrier directly using your tracking number to schedule your delivery.
It is your responsibility to ensure a safe and secure delivery environment. We are not liable for any packages that are stolen or lost after delivery is confirmed.
Please verify your shipping address carefully. Changes to your shipping address after the freight has been shipped may result in additional fees of 15% or more, depending on freight weight and dimensions.
SMALLWARES INFORMATION
Smaller items such as Installation Kits, Smart Connectivity Dongles, and TTW Sleeves may be shipped via FedEx without a signature requirement if ordered individually.
It is your responsibility to ensure a safe delivery location. We are not liable for packages lost or stolen after delivery confirmation. Thank you for your understanding and cooperation.
INSPECT YOUR MERCHANDISE BEFORE SIGNING
Please inspect your boxes carefully upon delivery. Shipments should arrive shrink-wrapped and on a pallet. If you notice any damage or signs of mishandling (such as a crushed box or forklift puncture), write comments on the delivery receipt before signing, even if the damage appears minor.
Contact us immediately if any issues arise so we can assist you promptly.
SMS Delivery Notifications
If you opted into SMS notifications, we may send you order updates or delivery reminders by text message. Message frequency may vary. Message and data rates may apply. Text STOP to opt out. Text HELP for assistance.
For more details, see our Privacy Policy.
Loading technical data…
