4 Ton Rheem 18 SEER2 R454B Side Discharge Heat Pump System RD18AY48AJVCA, RH2TY4821STANNJ
Forty-eight thousand BTU of inverter heat pump capacity from an outdoor cabinet less than 20 inches wide. The RD18AY48AJVCA builds vertically to 58 inches rather than outward, which is how Rheem fits 4 tons into a side yard that would never take a conventional condenser pad. Paired with the 21-inch RH2TY4821STANNJ two-stage air handler, the system is rated 18 SEER2 and 10 HSPF2 on R-454B refrigerant under AHRI reference 216980437.
Is a 4 Ton Heat Pump the Right Size?
Four tons covers roughly 2,000 to 2,400 square feet in a hot, humid climate and is a common specification for two-story homes on a single system, larger open-plan houses, and single-phase light commercial suites. It also has to carry the heating load, and the inverter compressor's 45% to 100% range means this unit can operate at about 1.8 tons during mild weather instead of cycling hard.
At this capacity the indoor match matters more than it does at 2 or 3 tons. The RH2TY4821STANNJ moves roughly 1,600 CFM at nominal on a 3/4 HP constant torque motor, and the step between its two airflow stages is a larger absolute swing than on the smaller cabinets. The system performs to its rating either way, but if the customer is sensitive to airflow changes or wants the quietest possible part-load operation, the constant CFM alternative is worth presenting alongside this one.
Ideal for: Two-story homes on a single system, 2,000 to 2,400 square foot open-plan houses, narrow side-yard and alley installations, and single-phase light commercial spaces.
Prefer continuously matched airflow? The 4 Ton RD18AY48AJVCA with the EcoNet RH2VY4821STACNJ air handler substitutes a constant CFM blower for the two-stage unit.
Recommended sizing ranges are general guidelines only. Actual system requirements depend on insulation, duct design, window area, ceiling height, occupancy, heating load, and local design conditions. Run our AC tonnage and BTU calculator, request free sizing assistance, contact Budget Heating, or call 813-885-7999.
What's Included
| Outdoor Heat Pump | RD18AY48AJVCA — 4 Ton Endeavor Line Prestige Series Side-Discharge Universal Heat Pump |
|---|---|
| Indoor Air Handler | RH2TY4821STANNJ Two-Stage Constant Torque Multiposition Air Handler |
| Application | Residential and Light Commercial Split Heat Pump System with Field-Installed Electric Backup Heat |
| Refrigerant | R-454B |
| Nominal Capacity | 48,000 BTU / 4 Tons |
| Rated Efficiency | 18 SEER2 Cooling / 10 HSPF2 Heating |
| Outdoor Cabinet | 19.8 in. W x 40.4 in. D x 58.0 in. H, approximately 296 lb |
| Air Handler Cabinet Width | 21 inches |
| AHRI Reference Number | 216980437 |
| Electrical | 208-230V, Single Phase, 60 Hz |
Size the electrical from the nameplate. Rheem lists the RD18AY48AJVCA at 38 A minimum circuit ampacity with 40 A maximum overcurrent protection, and the indoor circuit is sized separately once the electric heater kit is selected. A 58-inch-tall, 296-pound outdoor cabinet also has a different wind profile than a low square condenser, so follow the anchoring detail for your jurisdiction.
Heat Pump & Air Handler Features
RD18AY48AJVCA Side-Discharge Heat Pump
- 48,000 BTU from a cabinet only 19.8 in. wide by 40.4 in. deep
- 58 in. tall vertical cabinet, approximately 296 lb operating weight
- Inverter-driven variable speed twin rotary compressor, 45% to 100%
- 38 A minimum circuit ampacity, 40 A maximum overcurrent protection
- 61 dBA rated, with levels as low as 50 dBA at reduced speed
- Sound blanket, swept wing fan, and acoustically optimized tubing
- Brushless DC condenser motors enhance reliability and service access
- EcoNet enabled with built-in Bluetooth and PlusOne Diagnostics
- 7mm condenser copper coil reduces refrigerant charge requirements
- 10-year conditional parts warranty with registration
RH2TY4821STANNJ Air Handler
- 21-inch cabinet covering 3.5 and 4 ton airflow requirements
- 3/4 HP constant torque ECM blower motor
- Two-stage airflow with multiple selectable speed taps
- Roughly 1,600 CFM at 4 ton nominal
- 1.0 inch foil-faced insulation for quieter operation at higher CFM
- All-aluminum coil with internally grooved tubing
- Factory thermal expansion valve matched to R-454B
- 4-way convertible for upflow, downflow, and horizontal applications
- Accepts larger field-installed auxiliary heater kits
- Rugged steel cabinet with under 2% leakage at 1-inch H2O
Specifications & Manuals
Product documentation includes heat pump and air handler technical specifications and installation instructions to assist with equipment selection, permitting, installation, and service.
Frequently Asked Questions
Is the 4 ton outdoor cabinet really the same width as the 2 ton?
Yes. Both the RD18AY24AJVCA and RD18AY48AJVCA measure 19.8 inches wide by 40.4 inches deep. The 4 ton gains its capacity through height, standing 58 inches versus the 2 ton's 36.6 inches.
What return and duct capacity does this system need?
Plan for roughly 1,600 CFM. A return grille, filter rack, and trunk originally sized for a 3 ton system will restrict that airflow and raise external static pressure, which reduces delivered capacity regardless of the equipment rating.
Does the tall cabinet change the pad or anchoring requirements?
A 58-inch-tall unit at nearly 300 pounds has a higher center of gravity than a conventional condenser. In Florida and coastal jurisdictions, follow the anchoring and tie-down detail in the RD18AY installation instructions along with your local high-velocity hurricane zone requirements.
Is this air handler the same one used on 3.5 ton systems?
Yes. The RH2TY4821STANNJ serves both 3.5 and 4 ton applications, which is convenient for contractors carrying stock across both sizes. Only the outdoor unit, line set, and electrical sizing change between them.
How do I size the electric backup heat on a 4 ton heat pump?
Backup heat is sized from the heating load below the balance point plus the emergency heat expectation, not from the cooling tonnage. Available panel capacity also constrains the choice. Our heat strip guide covers the compatible Rheem kits.
Can the line set from my old R-410A system be reused?
Rheem lists traditional refrigerant piping compatibility as a replacement feature, but reuse depends on line size, condition, and cleaning per the RD18AY installation instructions. R-454B equipment is not backward compatible with R-410A outdoor units. See our copper lines and fittings if replacement is needed.
RD18AY Technical SpecificationsRD18AY Installation InstructionsRH2TY Technical SpecificationsRH2TY Installation InstructionsRheem Warranty Certificate
