3.5 Ton Rheem 15.2 SEER2 R454B Central System RA14AY42AJ1NA, RH2TY4821STANNJ
This 42,000 BTU Rheem Endeavor Line package marks the transition point in the RA14AY lineup: it is the first size to pair with the wider 21-inch RH2TY4821STANNJ air handler and its 3/4 HP ECM blower. The RA14AY42AJ1NA condenser holds a 15.2 SEER2 rating on low-GWP R-454B refrigerant under AHRI reference 215232971. Three and a half tons is the size that serves larger single-story homes and modest two-story houses that a 3 ton system leaves struggling on August afternoons.
Is a 3.5 Ton Refrigeration System the Right Size?
At 42,000 BTU per hour, a 3.5 ton system generally covers 1,800 to 2,100 square feet in a hot, humid climate. It is frequently the correct answer for four-bedroom single-story homes, homes with cathedral or tray ceilings that add conditioned volume without adding floor area, and houses with large unshaded glass on the south and west exposures.
This is also the point where duct capacity becomes the limiting factor more often than equipment capacity. The RH2TY4821STANNJ needs roughly 1,400 CFM to hit nominal, and a return system originally built for 3 tons will choke it. Before upsizing from 3 tons to 3.5, confirm that the return grille area, filter size, and trunk line can carry the additional airflow — otherwise the new system will run at higher static pressure and lose the efficiency you paid for.
Ideal for: Four-bedroom single-story homes, houses with vaulted or two-story great rooms, homes with large west-facing window walls, and small commercial suites.
Need more capacity? Step up to the 4 Ton Rheem 14.8 SEER2 R454B System RA14AY48AJ1NA, RH2TY4821STANNJ, which shares this same 21-inch air handler.
Recommended sizing ranges are general guidelines only. Actual system requirements depend on insulation, duct design, window area, ceiling height, occupancy, 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 Condensing Unit | RA14AY42AJ1NA — 3.5 Ton Endeavor Line Classic Series Air Conditioner |
|---|---|
| Indoor Air Handler | RH2TY4821STANNJ Two-Stage Multiposition Air Handler |
| Application | Residential Split System, Cool Only with Field-Installed Electric Heat |
| Refrigerant | R-454B |
| Nominal Capacity | 42,000 BTU / 3.5 Tons |
| Rated Efficiency | 15.2 SEER2 |
| Air Handler Cabinet Width | 21 inches |
| AHRI Reference Number | 215232971 |
| Electrical | 208-230V, Single Phase, 60 Hz |
Plan the closet before the equipment arrives. Moving from the 17.5-inch cabinet used on 1.5 through 3 ton systems to this 21-inch chassis adds three and a half inches of width plus service clearance. On retrofits that often means widening a closet opening or reworking the supply plenum, and it is the single most common surprise on a 3 to 3.5 ton upsize.
Condensing Unit & Air Handler Features
RA14AY42AJ1NA Outdoor Condensing Unit
- 3.5 ton nominal capacity, 42,000 BTU, rated 15.2 SEER2
- Highest efficiency tier available in the RA14AY family
- Low-GWP R-454B refrigerant, roughly 78% lower GWP than legacy blends
- 7mm condenser copper coil for reduced charge and lighter cabinet
- PlusOne Triple Service Access with 15-inch corner opening
- Individual and two-fastener removable corner panels
- Patented one-box PlusOne Refrigerant Detection System
- Automatic outdoor unit shutdown on refrigerant detection
- Composite base pan resists rust at the most failure-prone surface
- 10-year conditional parts warranty with Rheem registration
RH2TY4821STANNJ Air Handler
- 21-inch cabinet covering 3.5 and 4 ton applications
- 3/4 HP constant torque ECM blower motor
- Two-stage airflow with multiple selectable speed taps
- 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
- Field-installed heater kits with UL and cUL compliant breakers
- Rugged steel cabinet with under 2% leakage at 1-inch H2O
- Integrated A2L sensor and mitigation board, no field kit required
Specifications & Manuals
Product documentation includes condenser and air handler technical specifications, submittal data, installation instructions, and warranty information to assist with equipment selection, permitting, installation, and service.
Frequently Asked Questions
Why is the air handler wider on the 3.5 ton system?
Higher airflow needs more coil face area and a larger blower. The RH2TY4821STANNJ uses a 21-inch cabinet and a 3/4 HP ECM motor to carry 3.5 and 4 ton airflow, where the 17.5-inch cabinet tops out at 3 tons.
Will a 21-inch air handler fit where my 17.5-inch unit was?
Not always. Check the closet opening, door swing, and the supply plenum transition before ordering. Many retrofits require widening the framed opening or fabricating a new transition, and attic installs need adequate platform width and walkway clearance.
How much airflow does a 3.5 ton system need?
Roughly 1,400 CFM at nominal. If the existing return grille, filter rack, and trunk were sized for 3 tons, they will restrict that airflow and drive up external static pressure, which reduces both capacity and rated efficiency.
Is 15.2 SEER2 the top efficiency in this Rheem line?
Within the RA14AY family, 15.2 SEER2 is the highest published rating and it applies through the 3.5 ton size. The 4 ton pairing rates 14.8 and the 5 ton rates 13.8, because larger coils and blowers change the certified performance.
Does the R-454B charge require different line set sizing?
Line size, length, and vertical rise all affect charge and oil return, and R-454B systems follow the tables in the RA14AY and RH2TY documentation rather than assumptions carried over from R-410A. Our copper lines and fittings section stocks the common sizes.
What kind of homes typically need 3.5 tons rather than 3?
Homes with cathedral ceilings, two-story great rooms, large unshaded west glass, or additions that were never accounted for in the original duct design. Floor area alone will understate the load in any of those cases.
RA14AY Technical SpecificationsRheem Condenser BrochureRA14AY Submittal SheetRH2TY Technical SpecificationsRH2TY Installation InstructionsRH2TY Submittal SheetRheem Warranty Certificate
