4 Ton Rheem 18 SEER2 R454B Side Discharge Variable Speed Heat Pump System RD18AY48AJVCA, RH2VY4821STACNJ
Four tons of inverter-driven capacity in a cabinet under 20 inches wide. The RD18AY48AJVCA takes the same 19.8-inch footprint as the 2 ton unit and builds upward to 58 inches, which is how Rheem fits 48,000 BTU into a side yard that would never accept a conventional 34-inch-square condenser. Matched to the 21-inch RH2VY4821STACNJ constant CFM air handler, the system is rated 18 SEER2 and 10 HSPF2 on R-454B refrigerant under AHRI reference 216891868.
Is a 4 Ton Heat Pump the Right Size?
Forty-eight thousand BTU per hour typically covers 2,000 to 2,400 square feet in a hot, humid climate. It is a common specification for two-story homes served by a single system, larger open-plan houses, and light commercial spaces such as offices and small retail suites operating on single-phase power.
At this capacity the variable speed compressor earns its price difference most clearly. A 4 ton single-stage system in a house that only needs 1.8 tons on a mild spring afternoon will short-cycle badly and leave the air damp. The RD18AY throttles down to roughly 45% — about 1.8 tons — and simply runs, which is a fundamentally different comfort experience in shoulder seasons. Duct capacity still governs: the RH2VY4821STACNJ needs a return and trunk system sized for roughly 1,600 CFM.
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 suites.
Need more capacity? Step up to the 5 Ton Rheem 18 SEER2 Side Discharge Heat Pump System RD18AY60AJVCA, RH2VY6024STACNJ, the largest in the side-discharge range.
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 | RH2VY4821STACNJ EcoNet Enabled Constant CFM 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 | 216891868 |
| Electrical | 208-230V, Single Phase, 60 Hz |
Plan the electrical before delivery. Rheem lists the RD18AY48AJVCA at 38 A minimum circuit ampacity with 40 A maximum overcurrent protection, and the RH2VY4821STACNJ at 7 A MCA with a 15 A maximum before any heater kit is added. A field-installed electric heat kit will change the indoor circuit sizing substantially, so size the panel and the disconnects from the nameplate data rather than from tonnage.
Heat Pump & Air Handler Features
RD18AY48AJVCA Side-Discharge Heat Pump
- 48,000 BTU in 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
- Sound dampening blanket, swept wing fan, and optimized tubing design
- Brushless DC condenser motors for reliability and serviceability
- EcoNet enabled with Bluetooth PlusOne Diagnostics
- 7mm condenser copper coil lowers refrigerant charge requirements
- Optional base pan heater with integral thermostat for cold-climate installs
- 10-year conditional parts warranty with registration, no AHRI match required
RH2VY4821STACNJ Air Handler
- 21-inch cabinet, approximately 50.5 in. tall and 128 lb operating
- 3/4 HP constant CFM motor with a 300 to 1300 RPM range
- True variable speed airflow that tracks outdoor unit modulation
- 7 A minimum circuit ampacity before heater kit
- EcoNet enabled with homeowner alerts through the EcoNet App
- 1.0 inch foil-faced insulation and rugged steel cabinet
- All-aluminum coil with internally grooved tubing
- Factory thermal expansion valve for R-454B
- 4-way convertible for upflow, downflow, and horizontal installation
- Under 2% cabinet air leakage at 1-inch H2O per ASHRAE 193
Specifications & Manuals
Product documentation includes heat pump and air handler technical specifications, installation instructions, and submittal data to assist with equipment selection, permitting, installation, and service.
Frequently Asked Questions
How does a 4 ton unit fit in a cabinet under 20 inches wide?
By going vertical. The RD18AY48AJVCA keeps the 19.8-inch width and 40.4-inch depth of the 2 ton model and grows to 58 inches tall. The coil area comes from height rather than footprint, which is the whole design premise of the side-discharge series.
What breaker size does the RD18AY48AJVCA need?
Rheem lists 38 A minimum circuit ampacity and 40 A maximum overcurrent protection for this model. Always confirm against the unit nameplate, and size the indoor circuit separately once the electric heater kit is selected.
Does the taller cabinet affect wind load or tie-down requirements?
A 58-inch-tall, 296-pound unit has a different center of gravity and wind profile than a low square condenser. In Florida and coastal jurisdictions, follow the anchoring detail in the installation instructions and your local high-velocity wind zone requirements.
Can this system serve a small commercial space?
Four tons on 208-230V single phase is a common light commercial capacity for offices, salons, and small retail. Commercial installations may carry additional requirements for outside air and equipment access, so confirm with your local authority having jurisdiction.
How much airflow does the RH2VY4821STACNJ move?
The 3/4 HP constant CFM motor operates across a 300 to 1300 RPM range and targets roughly 1,600 CFM at 4 ton nominal. Specific speed settings and static pressure data are published in the RH2VY technical specifications linked above.
What heat strip capacity should I plan for on a heat pump?
On a heat pump the electric kit is backup and emergency heat, not the primary source, so it is sized to the balance point and the emergency heat expectation rather than the full heating load. Our Rheem heat strips section lists the compatible kits.
RD18AY Technical SpecificationsRD18AY Installation InstructionsRH2VY Technical SpecificationsRH2VY Installation InstructionsRH2VY SubmittalRheem Warranty Certificate
