Packaged Heat Pump System York WN 3 Ton | Montreal, Laval, Longueuil, South Shore and North Shore

A 3 ton commercial rooftop unit, without moving to three-phase

In many small commercial buildings in Montreal, Laval, Longueuil, the North Shore and the South Shore, the electrical service is single-phase. That is often the case for a neighbourhood convenience store, a professional's office, a service salon or a small unit on a commercial street. This YORK WN series packaged heat pump lets you install a 3 ton commercial rooftop unit directly on that supply, in 208/230 V single-phase, without taking on work to bring in three-phase. At AirGreen, we assess it, install it, start it up and maintain it.

Single-phase, a common reality in small commercial spaces

Bringing three-phase into a small commercial space is a project in itself, with its own costs and delays. In the KE/WN series, YORK offers exactly the 208/230-1-60 voltage for the 3, 4 and 5 ton sizes. The 3 ton model shown here suits modest-sized spaces that need a rugged commercial-grade unit, with a galvanized steel cabinet, base rails and full electronic control.

The whole system in one cabinet, connected to your ducts

A packaged heat pump brings together in one outdoor cabinet the scroll compressor, the outdoor coil, the indoor coil, the outdoor fan and the supply fan. The unit sits on the roof, on a roof curb, or on a pad at ground level, and connects directly to the supply and return ducts of the space. Nothing goes inside: no furnace in the back room, no coil in the ceiling, no refrigerant piping to run through the walls. For a business where every square foot is selling space, that is an immediate space saving. Each unit is also fully charged, wired, piped and tested at the factory, which simplifies installation on site.

Specifications of the WN036C00B1AAAAA1A1 model

• Nominal capacity: 3 tons (36,000 BTU/h)
• AHRI net cooling: 38,000 BTU/h, EER2 of 11.4
• Heating at 47 °F (8.3 °C): 36,000 BTU/h, COP of 3.3
• Heating at 17 °F (-8.3 °C): 21,000 BTU/h, COP of 2.1
• Seasonal efficiency: 13.4 SEER2 and 6.7 HSPF2 (14.0 SEER and 8.0 HSPF under the former rating method, as published by YORK)
• Nominal airflow: 1,250 CFM
• Supply: 208/230 V single-phase, 60 Hz (applied voltage from 187 to 252 V)
• Dimensions (width x length x height): 44.88 x 82.25 x 32.63 in.
• Operating weight: 610 lb
• Outdoor sound level (AHRI 270 standard): 83 dB(A)
• Refrigerant: R-454B, an A2L refrigerant with low global warming potential

What your electrical panel has to allow for

According to the electrical tables in the YORK technical guide, this unit (standard belt-drive indoor fan, no powered convenience outlet) calls for a minimum circuit ampacity (MCA) of 26.3 A, with a fuse or breaker of no more than 35 A, when no electric heat kit is added.

Electric backup heat changes the calculation. The kits compatible with this model in single-phase run from E05 to E20, that is from 5 to 20 kW. With the largest one, the MCA reaches 121.8 A at 208 V and 136.7 A at 230 V. YORK also states that the elements are rated at their nominal voltage: wired at 208 V, they deliver about 75% of their rated capacity. Before choosing the kit, we therefore check the capacity of your electrical service, the space available in the panel and the voltage actually measured at the building. The disconnect, supplied on site, is installed at the location the manufacturer clearly identifies on the cabinet.

A standalone control, simple to use day to day

The version offered here uses the Smart Equipment control in standalone mode. It works with a conventional thermostat wired to a screw terminal block or with a zone sensor, without a building management system. Factory-installed sensors measure the supply air, the return air and the outdoor air. The built-in LCD display, with its navigation joystick, shows the unit's status, the current mode, those temperatures and the fault codes.

The USB port allows data logging, reading of current and past faults, software updates as well as self-test and start-up reports. The board keeps the last five alarms, even after a power failure. It also applies the "three times, then shutdown" logic: the high and low pressure switches and the freeze protections have to trip three times in two hours before the compressor is locked out, which avoids a service call for an isolated trip. An anti-short-cycle delay and programmable minimum run times protect the compressor when the store door opens and closes all day long.

Another advantage for a convenience store, where the refrigerated cases give off heat even in spring: the built-in low ambient control lets the compressor cool down to 0 °F (-17.8 °C) outdoor, with no additional accessory.

The configuration supplied and the other factory option

The WN036C00B1AAAAA1A1 model is supplied with a belt-drive indoor fan (standard static pressure), the RDS refrigerant detector, the standalone Smart Equipment control, standard coils and 1 in. disposable filters, with no economizer and no optional sensor. The RDS monitors for R-454B inside the cabinet: in case of a leak, it raises an alarm and automatically starts a dilution sequence.

YORK also builds, still in single-phase, the WN036C00B1CAACA1A1. That configuration adds an economizer (without a barometric relief damper) and the BACnet MS/TP, Modbus or N2 communication card. The economizer can bring in up to 100% outdoor air to cool the space without the compressor when the weather allows. We confirm the right configuration during the estimate, based on your ventilation needs and the use of your space.

Installation notes for a small commercial roof

• Roof curb: the YORK 8 in. or 14 in. curbs, meeting NRCA requirements, nest inside the base rails and include a nailing strip and duct supports.
• Ducts: the connection is made from underneath, through the roof curb, or horizontally at the back, by simply removing the panels provided for that purpose.
• Clearances: allow 72 in. clear above the unit for the condenser air discharge, with no overhang or obstruction.
• Condensate: to limit drain freezing in winter, YORK offers as an option a bottom drain connection, which runs inside the roof curb.
• Filters: three filters to replace (two 15 x 20 in., one 14 x 25 in.); since the rack also accepts a 2 in. thickness, thicker pleated filters can be installed later with no modification.
• Heating: like any air-to-air heat pump, capacity drops as it gets colder, from 36,000 BTU/h at 47 °F to 21,000 BTU/h at 17 °F. The electric kit takes over; we size it according to the actual heat loss of your space.

Your small business in good hands with AirGreen

Everything starts with a free on-site estimate. We record the condition of the roof and the ducts, check the single-phase electrical service, calculate the heating and cooling loads, then propose the backup heat kit and the factory configuration that suit. Our crews then handle delivery, hoisting, connections and start-up, then seasonal maintenance: filters, coils, belt and reading the alarms recorded by the control.

AirGreen inc. is a Montreal HVAC contractor that sells and installs the equipment it recommends. Whether your business is in Montreal, Laval, Longueuil, on the North Shore or on the South Shore, call 514 316-2973 or use the form on airgreen.ca to book your free on-site estimate. You will quickly receive a clear, detailed quote.