YORK P Series Wall-Mounted Heat Pump 18 SEER | 9000 BTU 220V

A particularly interesting 9,000 BTU size when a room does not need an oversized heat pump

The YORK P Series 9,000 BTU 220 V wall-mounted heat pump belongs to a category of equipment we use when a specific area needs to be treated without unnecessarily installing a much higher capacity. A primary bedroom, enclosed office, small condo, addition, or section of a home that is difficult to cool are examples where a 9,000 BTU unit can make much more sense than a 12,000 or 18,000 BTU unit, provided the load calculation confirms it.

In YORK documentation, the P Series is a single-zone mini-split range with Inverter technology. The principle is important: instead of operating continuously according to an on-or-off logic, the compressor modulates its capacity according to the heating or cooling demand. YORK explains that its ductless systems adjust refrigerant flow according to the zone’s needs and use an Inverter compressor to maintain the temperature more precisely.

For this version, the combination that interests us is very specific: the DHP09NWB21S indoors and DHP09CSB21S outdoors, powered by 208/230 V. YORK clearly identifies this pair as the 9,000 BTU/h, 208/230 V P Series heat pump.

There is, however, a technical nuance that we believe is important to present clearly. The family’s commercial name is “P Series 18 SEER”, hence this product’s title, but the performance table for the DHP09NWB21S + DHP09CSB21S combination indicates a SEER of 16, an EER of 10, and an HSPF of 9. The term “18 SEER” therefore describes the series and its maximum performance depending on the configurations, but not necessarily the exact rating for every capacity.

At AirGreen, this type of distinction matters. When a homeowner in Montreal, Laval, Longueuil, the North Shore or the South Shore compares several heat pumps, we prefer to examine the AHRI combination and the exact numbers of both units rather than focus on the general name printed on a brochure.

DHP09NWB21S and DHP09CSB21S: the technical figures that really matter

The AirGreen product sheet identifies the DHP09CSB21S outdoor unit, the DHP09NWB21S indoor unit, and reference AHRI 8578537. YORK documentation then allows us to go much further into the specific characteristics of this combination.

The main published specifications are:

• Rated cooling capacity: 9,000 BTU/h
• Cooling range: 3,100 to 9,600 BTU/h
• Rated heating capacity: 9,500 BTU/h
• Heating range: 3,100 to 12,000 BTU/h
• EER: 10
• SEER: 16 for this specific combination
• HSPF: 9
• Power supply: 208/230 V, single-phase, 60 Hz
• Rated cooling current: 4 A
• Rated heating current: 3.6 A
• MCA: 9 A
• MOCP/MOP: 15 A
• Refrigerant: R410A
• Refrigerant piping: 1/4 in. liquid and 3/8 in. gas
• Drain: 5/8 in.
• Maximum piping length: 49.2 ft, or 15 m
• Maximum elevation difference: 33 ft, or 10 m
• Heating operating range: -20 °C to 24 °C
• Cooling operating range: -18 °C to 46 °C

These values help clarify the role of this YORK unit. It is a small wall-mounted heat pump capable of dropping to approximately 3,100 BTU/h when demand is low and increasing to as much as 12,000 BTU/h in heating within its published modulation range. This range is particularly relevant in a small room, where a unit that constantly operates at full capacity would often be uncomfortable.

Why a 9,000 BTU capacity may be preferable to 12,000 BTU

During our air conditioning and heating projects in Greater Montreal, we regularly see the same pattern: a homeowner prefers to buy a larger unit “to be safe.” Yet in HVAC, more BTUs are not automatically an improvement.

An oversized unit can reach the requested temperature too quickly, shorten its operating time, and provide less effective humidity control. It may also create excessive drafts in a small bedroom.

Conversely, an undersized unit may risk operating near its limit for extended periods.

To determine whether the YORK 9,000 BTU is suitable, we consider the room’s area, ceiling height, number and size of windows, sun exposure, insulation, floor level, and airflow to adjacent spaces.

In a Montreal duplex, for example, a third-floor bedroom with a large west-facing window does not necessarily have the same cooling load as a room of identical size on the shaded ground floor. That is precisely why we avoid selecting a wall-mounted heat pump based solely on the number of square feet.

A compact indoor unit: 31 in wide

The DHP09NWB21S indoor unit measures approximately 31 × 11 × 8 in, or 790 × 275 × 200 mm according to YORK. It weighs only about 20 lb net.

This size is useful in bedrooms and offices where the available space above a door or between two walls may be limited.

The outdoor unit is also relatively compact: 30.5 × 21 × 12.5 in, or 776 × 540 × 320 mm. The brochure indicates an outdoor sound pressure level of 52 dB(A) for the DHP09CSB21S.

In densely built-up areas of Montréal, this size often makes positioning easier than a high-capacity condenser. However, this does not eliminate the need to comply with clearances, applicable municipal requirements, and an installation that limits disturbances for neighbors.

Four measured airflow rates and indoor operation down to 28 dB(A)

The YORK specifications list four airflow values for the DHP09NWB21S:

318 / 288 / 241 / 171 CFM.

The corresponding sound pressure level ranges from 42 / 38 / 34 / 28 dB(A).

The minimum level of 28 dB(A) is particularly relevant for installation in a bedroom. However, the actual perceived noise depends not only on the figure listed in the technical specifications. The evaporator’s position, its proximity to the bed, vibrations transmitted to the wall, and even the cleanliness of the blower wheel can change the acoustic perception.

During an HVAC installation, we therefore try to avoid placing the unit directly a few feet from the face of someone sleeping. A quiet heat pump installed in the wrong place can become more bothersome than a slightly louder unit that is better positioned.

Automatic vertical and horizontal louvers: a useful feature in small spaces

The P Series features a more comprehensive air-control system than a simple vertical louver. The YORK function chart lists 3D Auto Swing, described as automatic vertical and horizontal sweeping. The P range also offers up-down and left-right swing, as well as fixed-angle adjustment.

This is consistent with the AirGreen product sheet, which states:

Vertical control: Auto
Horizontal control: Auto

For us, this feature is more useful than it may seem. In a narrow room, it is often preferable to direct the air lengthwise rather than straight toward the opposite wall. In a bedroom, we can direct the airflow to reduce the direct draft over the bed. In a small living room opening onto a kitchen, horizontal movement can help distribute the air more evenly.

However, louver movement does not turn a single-zone heat pump into a multi-zone system. A closed door remains a significant barrier to air circulation.

Wi-Fi: yes, but with an adapter

The AirGreen product sheet correctly indicates optional Wi-Fi.

YORK documentation specifies that the P and X Series use the EWPE Smart App and require the CS532AH adapter to enable this function. The app then allows the system to be controlled from a phone or tablet.

The DRCPX infrared remote control, on the other hand, comes standard with the P and X Series.

This distinction avoids a fairly common misunderstanding: the presence of the Wi-Fi symbol in a brochure does not necessarily mean that connectivity is already built into the wall-mounted unit.

Heating down to -20 °C: understanding what this figure means

YORK provides a heating operating range of -4 °F to 75 °F, corresponding to -20 °C to 24 °C, for the DHP09CSB21S.

However, a misinterpretation must be avoided. An operating limit of -20 °C does not automatically mean that the unit still produces its 9,500 nominal BTUs when the outdoor air temperature is -20 °C.

The supplied brochure does not provide a detailed capacity table for this combination at -8 °C, -15 °C, and -20 °C. We therefore cannot arbitrarily assign a heating capacity at these temperatures.

This is particularly important in Quebec. A homeowner in Laval, Terrebonne, Blainville, Longueuil, or Boucherville who wants their heat pump to be the primary heating source must distinguish three elements: the minimum operating temperature, the capacity actually available at that temperature, and the corresponding energy efficiency.

The 9,000 BTU YORK P can therefore operate within the published range down to -20 °C, but the provided documentation does not allow us to affirm that it retains 100% of its rated capacity at that temperature.

ENERGY STAR and subsidies: do not confuse cold-weather operation with cold-climate certification

The current product sheet provided by AirGreen classifies this model as ENERGY STAR: No and ENERGY STAR Cold Climate: No. The provincial subsidy section does not display an amount.

This information is consistent with the product's positioning: a heat pump may be capable of operating below zero without carrying ENERGY STAR cold-climate certification.

For a customer whose absolute priority is access to a Quebec subsidy, we recommend verifying the AHRI number's eligibility at the time of submission rather than assuming that a heat pump is eligible simply because it heats at low temperatures. Programs and criteria may change, while the exact combination number remains the item to verify.

SEER, SEER2, HSPF, and HSPF2: be mindful of different standards generations

The attached YORK brochure dates from November 2020. It therefore primarily uses the older SEER, EER, and HSPF metrics.

For the DHP09NWB21S with DHP09CSB21S, it publishes SEER 16, EER 10, and HSPF 9.

A SEER value should not be taken and simply renamed SEER2, nor should an approximate conversion be made when the official rating for the combination is unavailable. The testing procedures are not identical.

On a product page intended to properly inform a homeowner, we prefer to clearly separate:

confirmed historical data from the YORK brochure,
current AHRI data when available,
and current subsidy classifications.

This method reduces errors that sometimes arise when an older heat pump is integrated into a modern database designed around the SEER2 and HSPF2 fields.

What the installation actually changes regarding the comfort, noise, and lifespan of this YORK

1/4 in – 3/8 in piping: a detail to check during a replacement

The 9,000-BTU combination uses a 1/4 in. liquid line and a 3/8 in. gas line. YORK limits the total piping length to 49.2 feet, with a maximum height difference of 33 feet.

This information becomes particularly important when a customer wants to replace an older heat pump while keeping the existing piping.

We never assume that an older 9,000- or 12,000-BTU system automatically has the correct diameters. We check the lines, their condition, length, and compatibility before deciding whether they can be reused.

Improper piping can cause problems with refrigerant flow, oil return, and compressor operation. On a heat pump installation in Montreal or on the South Shore, this check takes a few minutes but can prevent a much more costly problem after commissioning.

208/230 V electrical circuit: MCA 9 A and maximum protection 15 A

The term “220 V” used commercially corresponds here to a nominal supply of 208/230 V, 1 phase, 60 Hz.

YORK specifies for the heat pump:

MCA: 9 A
MOCP: 15 A

MCA represents the minimum required circuit ampacity, while MOCP or MOP indicates the maximum overcurrent protection recommended by the manufacturer.

For the installation, we check the nameplate data for the equipment actually delivered as well as the available circuit. This is more reliable than choosing a circuit breaker solely based on the number of BTUs.

Drainage deserves as much attention as the refrigeration lines

The DHP09NWB21S drain is specified at 5/8 po.

On a wall-mounted heat pump, a significant portion of water-related service calls is not caused by the refrigeration circuit but by condensate drainage: insufficient slope, dirt buildup, a crushed line, an improper connection, or a blockage.

We therefore pay close attention to the drain route during installation. A line that looks aesthetically pleasing but rises slightly behind a wall can become problematic on very humid days in July.

In Montreal apartments and plexes, where layouts can be complex, it can sometimes be better to choose a slightly more visible but technically correct route than a hidden path that compromises airflow.

Maintenance: why 318 CFM today does not guarantee 318 CFM after several seasons

The documentation specifies up to 318 CFM of airflow. This figure obviously assumes that the unit is operating under normal conditions and that the filters, heat exchanger, and blower wheel allow adequate circulation.

Over time, dust can accumulate on the blower wheel. Airflow gradually decreases, and the owner may become accustomed to the change without realizing it. The unit may then run longer, become noisier, or produce less uniform air distribution.

Proper HVAC maintenance therefore involves more than simply cleaning the filters superficially. When the unit is heavily used for cooling, inspecting the evaporator, blower wheel, and drain becomes particularly relevant.

Warranty: 10 years on the compressor and parts after the applicable registration requirements are met

The AirGreen listing indicates a warranty of 10 years on the compressor – 10 years on parts – 0 years on labor for this offer.

The YORK brochure explains the original warranty structure more precisely: 7 years on the compressor and 5 years on parts under the standard warranty, with an extension to 10 years on the compressor and 10 years on parts after online registration for eligible residential installations. Ten years of labor coverage was also offered as a separate option.

This difference explains why registering the equipment after installation is important. We always recommend keeping the model numbers, serial numbers, invoice, and proof of installation with the property documents.

A typical scenario: small bedroom, oversized unit proposed elsewhere

A case we regularly encounter in our estimates is that of a small area where the owner received a recommendation for 12,000 BTU simply because that capacity is more commonly in stock.

Our approach is instead to look at the actual load.

If a closed room can be properly served by a 9,000 BTU unit, installing more capacity does not necessarily provide greater comfort. The DHP09NWB21S can go down to approximately 171 CFM at the lowest published airflow, with an indoor sound pressure level of 28 dB(A). This corresponds precisely to the type of operation sought in a room where quietness and gentle airflow matter as much as maximum power.

Conversely, we never force a 9,000 BTU unit into an open-concept area that genuinely requires more capacity simply to take advantage of the unit’s compact size.

Why choose AirGreen for a YORK installation in Greater Montréal

For us, selling a YORK wall-mounted heat pump does not simply mean delivering two boxes.

The quality of the result depends on capacity selection, indoor unit placement, condenser support, refrigerant-line routing, drain slope, electrical circuit, outdoor-air discharge, and commissioning.

We work with the particular realities of buildings in Montréal, Laval, Longueuil, the North Shore, the South Shore, and Montérégie: plexes with masonry walls, condos with condominium regulations, homes with limited available façade space, difficult piping routes, balcony installations, and replacements where existing lines must be carefully inspected.

That is also why we analyze the exact model numbers rather than relying solely on the “18 SEER” label. For this YORK, the documentation confirms a 9,000 BTU DHP09NWB21S + DHP09CSB21S heat pump in 208/230 V, with 9,500 nominal BTU in heating, heating modulation up to 12,000 BTU, R410A, 1/4–3/8 piping, published operation down to -20 °C, and Wi-Fi connectivity available with an adapter.

Contact AirGreen to verify whether 9,000 BTU is the right capacity

The YORK P Series 9,000 BTU 220 V can be a highly suitable solution when installed in an area whose load truly matches its capacity. Its compact design, inverter operation, automatic vertical and horizontal louvers, low sound levels, and 1/4–3/8 piping make it an interesting configuration for many residential projects.

Before purchasing, however, we recommend confirming the required capacity, condenser location, line-set length, electrical supply, and expectations for winter heating.

Contact AirGreen for a quote and a recommendation tailored to your property in Montréal, Laval, Longueuil, the North Shore, or the South Shore. We can confirm whether this 9,000 BTU YORK is suitable for your area or guide you toward a more appropriate capacity when the project calculation requires it.