York® Sunline XN Series Packaged Heat Pump Rooftop Unit – Supplied & Professionally Installed by 4Most Energy
The York® Sunline XN Series is a factory-assembled, single-package heat pump rooftop unit built for small commercial buildings in the 3 to 5 nominal ton range. It delivers up to 14.0 SEER cooling and 8.0 HSPF heating from one factory-charged cabinet, with R-410A refrigerant, micro-channel aluminum condenser coils, and the Smart Equipment™ control board with on-board diagnostics and USB data logging standard on every XN036 through XN060 model. A scroll compressor (2-speed on the XN060) and built-in low-ambient control allow cooling operation down to 0°F outdoor ambient. Heating is rated at 3.20–3.35 COP at 47°F, dropping to 2.10–2.2 COP at 17°F, at which point factory- or field-installed nickel chromium electric heat (5 to 30 kW) engages as backup. Full-perimeter base rails, forklift slots, and a shared cabinet footprint across all three sizes simplify rigging, curb selection, and future service — and with no on-site combustion, the Sunline XN is a straightforward path to building electrification.
Rated performance depends entirely on correct field installation. Ontario installations require ESA-compliant electrical hookup sized to the unit's MCA/MOCP rating, which varies meaningfully by voltage (208/230-1-60, 208/230-3-60, 460-3-60, or 575-3-60) and electric heat kW selection, along with refrigerant charge verification and correct heat pump/electric heat changeover setup. Roof curb selection (8 in. or 14 in. NRCA-approved curbs), structural load review, and sealed duct connections at the unit's bottom or horizontal openings are equally code-driven and equally easy to get wrong without an experienced crew. 4Most Energy handles packaged heat pump installation in Toronto, packaged rooftop replacement across the GTA, and York Sunline XN installation projects throughout Ontario — so the SEER and HSPF figures on the nameplate are what the building actually gets, not just what's on the spec sheet.
Replacement Option
The York® Sunline XN Series shares a common roof curb across every size in the line, and — using an appropriately sized curb adapter to bridge differing roof curb and duct footprints — it can replace aging Trane, Lennox, Daikin, Rheem, and AAON packaged heat pump or straight-electric units of comparable tonnage. This lets 4Most Energy convert a building to a proven, all-electric rooftop heating and cooling solution without necessarily requiring a full roof curb and structural rework, minimizing both project cost and rooftop downtime.
Warranty
York backs the Sunline XN Series with a 1-year limited warranty on the complete unit, a 5-year limited warranty on the compressor, and a 5-year limited warranty on factory-installed electric heater elements (when equipped). 4Most Energy handles warranty registration and start-up documentation on your behalf.
Documents
Why Install the York Sunline XN with 4Most Energy?
- R-410A refrigerant with micro-channel coils a proven, widely serviced refrigerant paired with micro-channel aluminum condenser coils for improved heat transfer and a reduced refrigerant charge.
- Smart Equipment™ control board embedded LCD display, on-board USB port for data logging and software updates, on-board diagnostics with fault code memory, and compatibility with a standard thermostat, zone sensor, or BACnet MS/TP, Modbus, and N2 building automation protocols.
- Heat pump heating with electric backup 8.0 HSPF rating with factory- or field-installed nickel chromium electric heat elements (5 to 30 kW, single or two-stage) providing supplemental capacity in low-ambient conditions.
- 2-speed scroll compressor (XN060) the 5-ton model uses a 2-speed compressor for improved part-load performance versus the single-speed compressors on the XN036 and XN048.
- Low-ambient operation to 0°F integrated low-ambient control allows cooling operation down to 0°F outdoor ambient without additional field-installed accessories.
- Anti-short cycle and nuisance-trip protection programmable minimum run times and a “three times, you're out” lockout philosophy on high/low-pressure switches and freezestats reduce false service calls.
- Convertible airflow design factory-covered duct openings convert between bottom and horizontal discharge without additional accessory panels.
- Full-perimeter base rails permanently attached, with forklift access from three sides and rigging holes for overhead crane placement.
- Factory-installed economizer options dry bulb or dual enthalpy economizers with AMCA 511 Class 1A low-leak dampers, capable of introducing up to 100% outdoor air for free cooling.
- Shared cabinet footprint all three sizes (3 to 5 tons) use the same cabinet and roof curb, simplifying future capacity changes or multi-unit sites.
Sunline XN Specifications
| Model | Nominal Tons | Net Cooling (Btu/hr) | SEER | EER | Heating at 47°F (Btu/hr) | COP at 47°F | HSPF | Sound (dBA, AHRI 270) | Operating Weight (lb) |
|---|---|---|---|---|---|---|---|---|---|
| XN036 | 3.0 | 37,000 | 14.0 | 12.0 | 36,000 | 3.35 | 8.0 | 76 | 610 |
| XN048 | 4.0 | 47,000 | 14.0 | 11.8 | 44,000 | 3.20 | 8.0 | 80 | 616 |
| XN060 | 5.0 | 55,400 | 14.0 | 11.0 | 51,500 | 3.35 | 8.0 | 80 | 620 |
Net cooling capacity and SEER/EER rated per AHRI Standard 210/240; cooling sound ratings per AHRI Standard 270. All models share the same
82-1/4 in. L × 44-7/8 in. W × 32-5/8 in. H cabinet footprint and roof curb.
| Low-Ambient Heating (heat pump output at 17°F) | XN036 | XN048 | XN060 |
|---|---|---|---|
| Heating at 17°F (Btu/hr) | 19,000 | 24,900 | 30,000 |
| COP at 17°F | 2.20 | 2.10 | 2.14 |
| Electric Backup Heat | 5–30 kW | 5–30 kW | 5–30 kW |
| Base Unit Electrical (Voltage – RLA/LRA · MCA · Max Fuse) | XN036 | XN048 | XN060 |
|---|---|---|---|
| 208/230-1-60 | 16.7/109 · 38.9 A · 50 A | 19.6/130 · 44.0 A · 60 A | 27.1/152.9 · 51.0 A · 70 A |
| 208/230-3-60 | 11.2/88 · 29.6 A · 40 A | 13.7/83.1 · 34.2 A · 45 A | 16.5/110 · 37.7 A · 50 A |
| 460-3-60 | 5.5/43.2 · 14.8 A · 20 A | 6.2/41 · 16.3 A · 20 A | 7.2/52 · 17.5 A · 20 A |
| 575-3-60 | 3.8/34 · 11.3 A · 15 A | 4.8/33 · 13.0 A · 15 A | 5.5/38.9 · 13.9 A · 15 A |
Electrical data shown for base units without electric heat (belt drive). Electric heat accessories (5 to 30 kW) substantially increase MCA and
max fuse/breaker sizing — exact figures are confirmed for the selected kW and staging before finalizing the electrical design. A field-supplied
and field-installed disconnect switch is required by code on all sizes.
The Sunline XN is sized first by cooling load (3–5 nominal tons) using a proper commercial load calculation — not by matching the tonnage of the unit being replaced, since older rooftop units on the same curb were frequently oversized. Because heat pump output declines as outdoor temperature drops (from 3.20–3.35 COP at 47°F to 2.10–2.2 COP at 17°F), sizing should also weigh the building's design heating load against the unit's 17°F output and the available electric backup heat capacity (5 to 30 kW) for Ontario's coldest design days. Because all three sizes share the same cabinet and roof curb, a tonnage change within the XN036–XN060 range typically does not require a new curb. 4Most Energy performs load calculation, electrical capacity verification, and curb/structural review as part of every quote before ordering.
Installation & Assessment Checklist
| Phase | Description & Key Requirements | |
|---|---|---|
| Step 1 | Site Assessment | Existing equipment inspection, electrical service review, and roof curb, slab, or steel-beam mounting evaluation. |
| Step 2 | Load Calculation & Unit Sizing | Confirm correct tonnage, electric backup heat capacity, economizer/BAS requirements, and duct configuration (bottom or horizontal). |
| Step 3 | Rigging & Placement | The Sunline XN's full-perimeter base rails, forklift slots, and rigging holes allow forklift or overhead crane placement onto the roof curb, slab, or beams. |
| Step 4 | Roof Curb & Structural Prep | Install or verify the correct 8 in. or 14 in. NRCA-approved roof curb, full-perimeter gasketing, and structural support. |
| Step 5 | Electrical Connection | ESA-compliant hookup to a field-installed disconnect switch, sized to the unit's MCA/MOCP rating for the building's voltage, phase, and selected electric heat kW. |
| Step 6 | Ductwork Tie-in | Supply and return duct connection matched to bottom or horizontal discharge, with sealed transitions. |
| Step 7 | Refrigerant & Controls Commissioning | Refrigerant charge verification, Smart Equipment™ control board configuration (thermostat, zone sensor, or BAS integration), and heat pump/electric heat changeover setpoints. |
| Step 8 | Airflow & Performance Verification | Confirm airflow and heating/cooling changeover operation, with start-up documentation and warranty registration filed. |
| Step 9 | Final Walkthrough | Filter access, service clearances, and control board operation demonstrated before the crew leaves site. |
York's standard coverage on the Sunline XN Series is a 1-year limited warranty on the complete unit, a 5-year limited warranty on the compressor, and a 5-year limited warranty on factory-installed electric heater elements (when equipped). 4Most Energy completes and files the required start-up documentation to keep warranty coverage valid.
Routine maintenance is straightforward by design: hinged, tool-less filter, motor, and electrical access panels speed up inspections, and the Smart Equipment™ board's on-board diagnostics and five-fault memory (retained through power loss) let a technician diagnose an issue before opening a single panel. 4Most Energy recommends annual refrigerant charge and defrost cycle verification, condenser and evaporator coil cleaning, and filter replacement (1 in. standard, 2 in. pleated MERV 8 optional). 4Most Energy offers scheduled maintenance plans covering filter changes, coil cleaning, refrigerant circuit checks, and control board diagnostics.
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
How is the Sunline XN Series different from the gas-heat Sunline ZE Series?
The XN Series uses a heat pump as the primary heat source with optional electric heat as backup, while the York Sunline ZE Series pairs cooling with single- or two-stage gas heat. Both share R-410A refrigerant, Smart Equipment™ controls, and the same cabinet/curb footprint, making the XN Series the electrification-focused option within the same platform.
How cold can it get before the heat pump needs electric backup?
The Sunline XN is rated at 3.20–3.35 COP at 47°F and 2.10–2.2 COP at 17°F. Below that range, or when the design heating load exceeds the heat pump's output, factory- or field-installed electric heat (5 to 30 kW) engages automatically to maintain space temperature.
What's different about the XN060's compressor?
The 5-ton XN060 uses a 2-speed scroll compressor, which modulates capacity for better part-load efficiency and comfort compared to the single-speed compressors on the XN036 and XN048.
Can I upgrade tonnage later without replacing the roof curb?
In many cases, yes — all three Sunline XN sizes share the same cabinet footprint and roof curb, so a future capacity change may not require new curb work. 4Most Energy always verifies electrical capacity for the new size before quoting.
Do you need a crane to install the Sunline XN?
It depends on roof height and access. The unit's full-perimeter base rails, three-side forklift slots, and rigging holes allow either forklift or overhead crane placement — we confirm the rigging method during the site assessment and include it in your quote.
What maintenance does the Sunline XN need?
We recommend annual refrigerant charge and defrost cycle verification, condenser and evaporator coil cleaning, and filter replacement. Tool-less access panels and the Smart Equipment™ board's fault memory keep service visits quick.
Does the Sunline XN Series qualify for Ontario electrification incentives?
Eligibility depends on each program's current efficiency thresholds, so 4Most Energy confirms it against the specific program when quoting. Most residential programs do not apply to commercial rooftop equipment.
