York® Sun™ Pro ZR Packaged Rooftop Unit with Hot Gas Reheat – Supplied & Professionally Installed by 4Most Energy
The York® Sun™ Pro ZR is a standard-efficiency convertible packaged rooftop unit purpose-built for applications that need active humidity control. Every unit ships with a factory-standard hot gas reheat coil, so no field-installed dehumidification accessory is required. It is rated up to 14.0 SEER on 3–5 ton models and 11.8 IEER on 6.5–12.5 ton models, across eight sizes from 3 to 12.5 nominal tons (ZR037 to ZR150), with gross cooling capacities from 36,000 to 154,000 Btu/h on R-410A refrigerant. Copper tube / aluminum fin coils and constant-volume blowers are standard, with a VAV/VFD option on 6.5–12.5 ton models. Two-stage gas heat uses aluminized steel (standard) or stainless steel (optional) tubular heat exchangers, and the unit is also available cooling-only or with electric heat. All sizes share a common cabinet footprint and roof curb with the Sun Pro ZH and ZJ lines.
Reliable dehumidification depends on correct field installation. Ontario installations require verified roof curb structural capacity, a properly sized gas line and venting for two-stage combustion, and electrical service matched to the unit's 208/230/460/575V, 3-phase rating. Reheat coil charge, combustion setup, and control staging must be commissioned correctly, or the unit will underperform against its rated capacity. 4Most Energy's licensed gas technicians perform combustion analysis, refrigerant charge verification for both the primary circuit and the reheat coil, and Smart Equipment™ controller commissioning on every packaged rooftop unit installation in Toronto and across the GTA, with each installation documented for TSSA and ESA compliance.
Replacement Option
The York® Sun™ Pro ZR can replace older Trane, Lennox, Daikin, Rheem, and AAON packaged rooftop units using an appropriate roof curb adapter, letting building owners add factory-integrated dehumidification without modifying existing roof penetrations or ductwork. Field-installed curb adapters are also available for transitioning from the York Sunline™ footprint. For larger 15–25 ton reheat applications, see the York Series 20 J**ZR.
Warranty
York backs the Sun™ Pro ZR with a 1-year complete unit warranty, a 5-year compressor warranty, and a 10-year aluminized steel gas heat exchanger warranty, extendable to 15 years with the optional stainless steel heat exchanger. 4Most Energy handles startup, combustion test documentation, and warranty registration on your behalf.
Documents
Why Install the York Sun Pro ZR with 4Most Energy?
Gas Heat & Combustion Expertise
Licensed TSSA gas technicians size the gas line for two-stage heat, verify supply pressure, and complete combustion analysis at startup.
Proper System Sizing
We start with a commercial block load calculation, then confirm tonnage, gas heat input, and electrical and gas capacity before ordering.
Professional Rooftop Installation
Crane or forklift placement using the base-rail rigging holes and forklift slots, curb verification, ductwork, gas, electrical, and controls coordinated in one project.
Reheat Coil Commissioning
Hot gas reheat setup and R-410A charge verification on both the primary circuit and the reheat coil, so the unit controls humidity and delivers its rated capacity.
Transparent Installation Planning
Before installation, we review the existing rooftop unit, curb, gas and electrical service, and access requirements, so your quote reflects the real scope of work.
Ongoing Maintenance Support
Semi-annual (spring and fall) reheat and evaporator coil cleaning, refrigerant charge checks, filter replacement, combustion analysis, and Smart Equipment™ diagnostics.
- Factory-standard hot gas reheat coil on every ZR model — dedicated humidity control without a separate field-installed accessory, ideal for retail, medical, and high-occupancy spaces.
- Standard-efficiency cooling up to 14.0 SEER (3–5 ton) or up to 11.8 IEER (6.5–12.5 ton), sized for applications prioritizing dehumidification over peak efficiency.
- Copper tube / aluminum fin evaporator coils for proven reliability across the full tonnage range.
- Service-friendly design the motor and blower slide out as one assembly, and a toolless door latch and hinged access panels simplify filter, compressor, reheat coil, and control box service.
- Two-stage gas heat 70–75% capacity on 1st stage (3–5 ton) or 60% (6.5–12.5 ton), with aluminized steel (standard) or stainless steel (optional) tubular heat exchangers.
- Smart Equipment™ control platform embedded LCD, on-board USB data logging, 5-fault diagnostic memory retained through power loss, and BACnet MS/TP, Modbus, N2, and Verasys communication.
- Constant-volume airflow standard with a VAV/VFD option on 6.5–12.5 ton models for variable air volume duct systems.
- Convertible side/down duct design side duct openings are covered at the factory and can be field-converted without panel cutting.
- Full-perimeter base rails forklift slots on three sides and rigging holes for 3-way forklift access and overhead crane placement.
- Common Sun Pro footprint shared with the ZH and ZJ lines, with field-installed curb adapters for transitioning from the York Sunline™ footprint.
Sun Pro ZR Specifications
| Model | Nominal Tons | Gross Cooling (Btu/h) | Net Cooling (Btu/h) | SEER | EER | IEER | Hot Gas Reheat Coil | Refrigerant Circuits | Compressor Stages | Gas Heat Efficiency |
|---|---|---|---|---|---|---|---|---|---|---|
| ZR037 | 3 | 36,000 | 35,000 | 14.0 | 11.5 | — | Standard | 1 | Single | 81% AFUE |
| ZR049 | 4 | 48,500 | 47,000 | 14.0 | 11.5 | — | Standard | 1 | Single | 81% AFUE |
| ZR061 | 5 | 59,000 | 57,000 | 14.0 | 11.5 | — | Standard | 1 | Single | 81% AFUE |
| ZR078 | 6.5 | 76,000 | 74,000 | — | 11.0 | 11.8 | Standard | 2 | Two | 81% thermal |
| ZR090 | 7.5 | 88,000 | 86,000 | — | 11.0 | 11.8 | Standard | 2 | Two | 81% thermal |
| ZR102 | 8.5 | 99,700 | 96,000 | — | 11.0 | 11.8 | Standard | 2 | Two | 81% thermal |
| ZR120 | 10 | 124,000 | 120,000 | — | 11.0 | 11.8 | Standard | 2 | Two | 81% thermal |
| ZR150 | 12.5 | 154,000 | 150,000 | — | 11.0 | 11.8 | Standard | 2 | Two | 81% thermal |
Baseline configuration shown: standard-static constant-volume indoor blower, no electric heat, two-stage gas heat where applicable. High-static and VFD/VAV blowers (6.5–12.5 ton),
electric heat, and other gas heat sizes are available. Ratings per AHRI standards.
| Model | Nominal Airflow (CFM) | Dimensions L × W × H (in.) | Operating Weight (lb) | Roof Curb Height (in.) | Electrical Service | Base Electrical MCA |
|---|---|---|---|---|---|---|
| ZR037 | 1,200 | 89 × 59 × 42 | 719 | 8 or 14 | 208/230/460/575V, 3-phase | Confirmed at quote |
| ZR049 | 1,600 | 89 × 59 × 42 | 748 | 8 or 14 | 208/230/460/575V, 3-phase | Confirmed at quote |
| ZR061 | 2,000 | 89 × 59 × 42 | 765 | 8 or 14 | 208/230/460/575V, 3-phase | Confirmed at quote |
| ZR078 | 2,500 | 89 × 59 × 50-3/4 | 1,033 | 8 or 14 | 208/230/460/575V, 3-phase | Confirmed at quote |
| ZR090 | 2,500 | 89 × 59 × 50-3/4 | 1,035 | 8 or 14 | 208/230/460/575V, 3-phase | Confirmed at quote |
| ZR102 | 3,300 | 89 × 59 × 50-3/4 | 1,044 | 8 or 14 | 208/230/460/575V, 3-phase | Confirmed at quote |
| ZR120 | 3,400 | 89 × 59 × 50-3/4 | 1,070 | 8 or 14 | 208/230/460/575V, 3-phase | Confirmed at quote |
| ZR150 | 3,500 | 119-1/2 × 59 × 50-3/4 | 1,280 | 8 or 14 | 208/230/460/575V, 3-phase | Confirmed at quote |
Base electrical MCA figures are model- and voltage-specific (208/230V, 460V, 575V) and are confirmed at the time of quote based on the exact configuration selected.
Refrigerant, compressor stage, and dimensional data reflect the base cooling-only configuration; consult 4Most Energy for configuration-specific values.
Sizing a Sun™ Pro ZR begins with a Manual N or equivalent commercial load calculation for the space, followed by confirmation that dehumidification is a functional requirement. The ZR's standard reheat coil is best suited to retail, medical, laboratory, gymnasium, or other high-occupancy or moisture-sensitive spaces where independent humidity control matters. If the application does not require reheat, the higher-efficiency Sun Pro ZH or ZJ lines (same cabinet footprint) will typically deliver lower operating costs. Within the ZR line, select nominal tonnage (ZR037 to ZR150) to match the calculated load, then confirm the blower configuration (standard-static constant-volume or high-static VAV/VFD) and gas heat input size based on building heating load and available gas service. For loads above 12.5 tons, see the Series 20 J**ZR (15–25 tons). 4Most Energy's site assessment confirms final model selection against actual roof curb, electrical, and gas infrastructure before ordering.
Installation & Assessment Checklist
| Phase | Description & Key Requirements | |
|---|---|---|
| Step 1 | Site Assessment | 4Most Energy evaluates roof curb condition and structural capacity, gas line sizing, and electrical service. |
| Step 2 | Equipment Selection | Confirm the ZR model, tonnage, blower configuration, and heat exchanger option based on the load calculation and dehumidification requirements. |
| Step 3 | Permitting | Secure required building, gas, and electrical permits per the Ontario Building Code and the local authority having jurisdiction. |
| Step 4 | Rigging & Placement | The unit is craned or forklifted into position on the roof curb using the base-rail rigging points. |
| Step 5 | Connection & Commissioning | Licensed technicians complete the gas line connection, electrical hookup, ductwork tie-in, refrigerant charge verification for both circuits, combustion analysis, and Smart Equipment™ controller setup. |
| Step 6 | Final Inspection & Documentation | Startup report, combustion test results, and warranty registration are completed and provided to the building owner. |
York® Sun™ Pro ZR units carry a 1-year complete unit parts warranty and a 5-year compressor warranty from the date of installation. The standard aluminized steel gas heat exchanger carries a 10-year warranty, extendable to 15 years with the optional stainless steel heat exchanger. Warranty coverage requires professional installation and startup by a licensed contractor, along with documented annual maintenance.
Because the ZR's reheat coil operates whenever dehumidification is called for, 4Most Energy recommends semi-annual maintenance visits (spring and fall) rather than the annual visit typical for standard cooling-only units. Maintenance includes reheat coil and evaporator coil cleaning, refrigerant charge verification for both circuits, filter replacement, electrical connection inspection, combustion analysis on gas-heat units, and control board diagnostic review via the Smart Equipment™ platform's on-board USB logging. 4Most Energy offers scheduled maintenance plans that keep this documentation in place for your warranty.
Service Area
Greater Toronto Area (GTA) and surrounding regions
Toronto, Markham, Richmond Hill, Vaughan, Aurora, Newmarket, Scarborough, Brampton, and Mississauga.
Extended Service Area: Stouffville, Oshawa, Barrie, Orangeville, Hamilton, St. Catharines, Guelph, Kitchener.
Frequently Asked Questions
What is the difference between the Sun Pro ZR and the ZH or ZJ lines?
All three share the same cabinet footprint and roof curb, but the ZR includes a factory-standard hot gas reheat coil for dedicated humidity control, while the ZH and ZJ prioritize cooling efficiency without a reheat function.
Do I need the reheat coil if I only need cooling and heating?
No. If your space does not have specific humidity control requirements, the higher-efficiency Sun Pro ZH or ZJ line will typically provide lower long-term operating costs in the same footprint.
What sizes does the Sun Pro ZR come in?
Eight sizes from 3 to 12.5 nominal tons (models ZR037 through ZR150), covering small commercial spaces through larger retail and institutional buildings. For 15 to 25 tons, see the Series 20 J**ZR.
Can the ZR replace my existing rooftop unit without changing the roof curb?
In many cases, yes. The ZR shares a common footprint with other Sun Pro models, and roof curb adapters are available for transitioning from York Sunline™ or other manufacturers' curbs. 4Most Energy confirms curb compatibility during the site assessment.
How is the Sun Pro ZR lifted onto the roof?
At 719 to 1,280 lb, the ZR is placed by crane or forklift using the base-rail rigging holes and forklift slots on three sides. 4Most Energy plans the lift and roof access during the site assessment and includes it in your quote.
What maintenance does the Sun Pro ZR need?
Because the reheat coil runs whenever dehumidification is called for, we recommend semi-annual visits (spring and fall): reheat and evaporator coil cleaning, refrigerant charge verification on both circuits, filter replacement, electrical inspection, combustion analysis on gas-heat units, and a Smart Equipment™ diagnostic review.
Are there energy rebates available for a Sun Pro ZR installation in Ontario?
Rebate eligibility depends on the efficiency tier and the specific commercial program's thresholds, so 4Most Energy confirms current utility incentive eligibility at the time of quote. Residential programs do not apply to commercial rooftop equipment.
