MRCOOL® Signature Series 18,000 BTU Stud-Mount Air Handler 1.5 Ton R-454B ECM, MCAEAWPEF18D21AA

Product Description 

The MRCOOL® Signature Series MCAEAWPEF18D21AA is a space-saving 18,000 BTU stud-mount air handler engineered for applications where traditional air handlers simply won’t fit. Designed to install directly between standard wall studs, this compact unit is ideal for remodels, tight mechanical spaces, apartments, additions, and modern high-efficiency builds where every inch matters.

Despite its slim profile, this 1.5-ton air handler delivers strong, consistent airflow (685 CFM) when paired with a compatible MRCOOL® Signature Series top-discharge condenser or heat pump. The flexible front or bottom return air configuration allows installers to adapt airflow to the layout of the space, while the upflow design ensures efficient air distribution.

Inside the galvanized steel cabinet, a high-efficiency ECM blower motor provides quiet operation, improved comfort, and reduced energy consumption compared to standard PSC motors. Full cabinet insulation minimizes heat loss, reduces condensation, and helps keep operating sound levels low. A built-in filter rack allows for fast, simple filter changes without removing the unit.

For colder climates or supplemental heat needs, this air handler supports optional electric heat kits (5kW, 7.5kW, or 10kW), giving homeowners additional flexibility. Designed to work with R-454B refrigerant, the system meets modern environmental standards while remaining future-ready. Backed by a 10-year parts warranty, the MRCOOL® Signature Series 18K Stud Mount Air Handler delivers reliability, efficiency, and smart design in a compact footprint.

KEY FEATURES & BENEFITS 

• 18,000 BTU / 1.5 Ton Capacity – Ideal for smaller zones & additions
• Stud-Mount Design – Fits between standard wall studs
• Slim, Space-Saving Cabinet – Perfect for tight installs
• 685 CFM Airflow – Strong, balanced performance
• ECM Blower Motor (1/3 HP) – Quiet, efficient operation
• R-454B Refrigerant Compatible – Low-GWP, future-ready
• Front or Bottom Return Air Options – Flexible installation
• Upflow Configuration – Efficient air delivery
• Galvanized Steel Cabinet – Long-term durability
• Fully Insulated Cabinet – Reduced noise & condensation
• Built-In Filter Rack – Easy maintenance

• Optional Electric Heat Kits – models below 
• 1. 5kW,      Model- MCAEHWD5X1AA
• 2. 7.5kW,   Model- MCAEHWD7X1AA
• 3. 10kW,    Model- MCAEHWD10X1AA

• AHRI Certified / UL / CSA / ETL Listed – Verified safety & performance

ELECTRICAL REQUIREMENTS 

• Voltage: 208/230V
• Phase: Single
• Max Fuse / Breaker: 3 Amps
• Minimum Circuit Ampacity (MCA): 2.5 Amps

DIMENSIONS & WEIGHT

Installed Unit Dimensions

• Width: 20.5 in
• Height: 36 in
• Depth: 15 in

Weight

• Net Weight: 88 lbs
• Shipping Weight: 97 lbs

WARRANTY INFORMATION  

• Base Warranty
  
• 10-Year Parts Warranty
• Limited Lifetime Compressor Warranty (when paired with compatible system)

FREQUENTLY ASKED QUESTIONS 

Q: What systems does this air handler work with?

A: It is designed to pair with MRCOOL® Signature Series top-discharge condensers and heat pumps.

Q: Can this be installed in tight spaces?

A: Yes. This unit is designed specifically to install between wall studs where standard air handlers won’t fit.

Q: Does this air handler include electric heat?

A: No, but optional electric heat kits (5kW, 7.5kW, or 10kW) are available.

Q: What refrigerant does this system use?

A: R-454B refrigerant, which meets modern environmental standards.

Q: Is professional installation required?

A: Yes. Professional installation is recommended to meet electrical, refrigerant, and local code requirements.

Why Buy From MRCOOL DIRECT?

When you order from MRCOOL Direct, you get:

• ✅ Authorized MRCOOL® dealer – Your warranty is protected
• ✅ Factory-fresh units – No refurbished or mystery sources
• ✅ Fast U.S. shipping – Most in-stock items ship in 1–3 business days
• ✅ Financing options – Make high-efficiency comfort more affordable
• ✅ Real product support – Help with sizing, line set selection, and DIY questions
• ✅ No third-party marketplace middlemen – Just genuine MRCOOL® systems from a trusted MRCOOL® dealer.

BUY DIRECT!

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615-553-8118

Family owned & USAs #1 MRCOOL® Authentication Dealer.