MRCOOL
MRCOOL Signature 42,000 BTU Split System Air Handler Multi-Position
3.5 Ton | R-454B | 208/230V
- 3.5 Ton capacity
- Uses R-454B refrigerant
- Runs on 208/230V power
Key Specifications
Product Overview
The MRCOOL® Signature Series 42k Multi-Position Air Handler is built to provide consistent, energy-efficient comfort in any climate. Designed for flexibility and performance, this unit works with R-454B refrigerant, a low-GWP alternative that helps reduce environmental impact without sacrificing power or reliability.
Its multi-position design allows for installation in upflow, downflow, or horizontal configurations, making it ideal for a variety of home layouts, from new construction to tight retrofits. With its slim, space-saving profile, it fits easily into closets, attics, or crawl spaces while still delivering full-capacity heating and cooling when paired with a compatible condenser or heat pump.
Engineered for durability, the air handler includes a galvanized steel cabinet, a high-efficiency ECM blower motor, and copper “A” coils with enhanced aluminum fins for superior heat transfer and humidity control. Thermal insulation inside the cabinet reduces energy loss and prevents condensation, contributing to quiet operation and lower energy bills.
Installation is fast and simple, helping to minimize labor time and disruption. An air filter rack allows for easy maintenance, while an optional electric heat kit is available for added heating performance in colder regions.
Smart home compatibility comes standard, with support for most third-party thermostats so you can manage comfort on your terms; no proprietary systems required.
Protected by a 10-year limited parts warranty, the MRCOOL® Signature Series 42k Multi-Position Air Handler offers long-lasting performance, space-saving design, and year-round efficiency for today’s comfort-conscious homeowner.
Additional specifications
| UPC | 840255595889 |
|---|---|
| Series | Signature Series Multi-Position Air Handler |
| Configuration | Multi-Position |
| Airflow (CFM) | 1254 |
| Cycle (Hz) | 60 |
| Min circuit ampacity (A) | 7.2 |
| Max fuse / breaker (A) | 10 |
| Blower motor type | ECM |
| Blower motor HP | 3/4 |
| Blower speeds | 5 |
| Metering device | Orifice |
| Drain connection (in) | 3/4 |
| Filter type | Replaceable |
| Filter size | 18 * 21 * 1 |
| Mount type | Multi-Position |
| Aux heater included | No |
| Aux heater available | Yes |
| Aux heater sizes (kW) | 5kW, 7.5kW, 10kW |
| AHRI certified | Yes |
| ENERGY STAR certified | No |
| UL listed | Yes |
| ETL listed | Yes |
| Parts warranty (years) | 10 Year |
| Compressor warranty (yrs) | Limited Lifetime |
| Shipping W x H x D (in) | 22.83 x 47.875 x 25.6 |
| Shipping weight (lbs) | 144 |
Documents
WARNING: This product can expose you to chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.p65warnings.ca.gov.
Technical Specifications
Performance
| System Type | Air Handler |
|---|---|
| Tonnage | 3.5 Ton |
| Sound Level | 54 dBA |
Electrical & Fuel
| Voltage | 208/230V |
|---|---|
| Phase | Single Phase |
| Refrigerant | R-454B |
| Connection Size | Liquid 3/8" / Suction 3/4" |
Physical & Certifications
| Dimensions (W x H x D) | 19.625 x 45.75 x 22 |
|---|---|
| Weight | 131 lb |
| Color / Finish | Grey |
Shipping & Delivery
Manufacturer Warranty
Covered by MRCOOL's limited warranty. Warranty terms are set by MRCOOL and differ by product line — whether registration is required, and whether the installation has to be performed by a state-licensed HVAC contractor, is not the same across the range. In every case coverage depends on the unit being installed according to MRCOOL's instructions and all applicable codes and permits. MRCOOL's warranty document for this model is the controlling source; ask us and we'll send you the one that applies.
Professional Installation Recommended
Most HVAC equipment must be installed and connected by a licensed professional to remain safe, code-compliant, and eligible for manufacturer warranty coverage. If you're unsure about installation requirements, contact us before you order.
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