YORK P Series Wall-Mounted Heat Pump 18 SEER | 9000 BTU 115V

A compact 115 V wall-mounted solution for small areas, with technical specifications that must be read carefully

For certain wall-mounted heat pump projects in Montreal, Laval, Longueuil, the North Shore, or the South Shore, 9,000 BTU is exactly what is needed: a bedroom, office, small condo, a separate area of a house, or a commercial space of limited size. The YORK P Series DHP09CSB11S / DHP09NWB11S adds an interesting feature to this category: it operates at 115 V, whereas many residential wall-mounted heat pumps are powered by 208/230 V.

However, this feature does not mean that it can simply be plugged into an existing wall outlet. This is precisely the kind of detail that can completely change the quality of an installation. At AirGreen, we assess the system as a whole: actual heating and cooling load, available electrical circuit, indoor unit location, condensate drainage, piping length, outdoor unit location, and expected performance when temperatures drop in winter.

It is also important to clarify a point concerning the name “P Series 18 SEER”. The YORK catalog does indeed present this family as the P Series 18 SEER, but the technical table for the specific 9,000 BTU 115 V model indicates a SEER rating of 16, an EER of 9.55, and an HSPF of 9. The current YORKNow network catalog also identifies the DHP09CSB11S / DHP09NWB11S pair as a 0.75-ton system rated at 16 SEER, associated with AHRI number 8578529.

This distinction is important: 18 SEER describes the product line, while the certified performance of the 9,000 BTU 115 V model must be read in its own technical data sheet.

DHP09CSB11S outdoors, DHP09NWB11S indoors: the exact combination

The YORK P Series referred to here is a single-zone wall-mounted heat pump with an inverter compressor consisting of:

• Outdoor unit: DHP09CSB11S
• Indoor unit: DHP09NWB11S
• Nominal cooling capacity: 9,000 BTU/h
• Nominal heating capacity: 9,600 BTU/h
• Power supply: 115 V, single-phase, 60 Hz
• Refrigerant: R-410A
• AHRI: 8578529
• SEER: 16 for this specific combination
• EER: 9.55
• HSPF: 9

The compressor’s modulation is a much more relevant point than nominal capacity alone. In cooling mode, YORK indicates an approximate range of 2,764 to 10,918 BTU/h. In heating mode, the published range is 2,081 to 12,283 BTU/h.

This means that the heat pump does not operate solely according to an on-off principle at 9,000 BTU. It can reduce or increase its output according to demand. In a room with moderate needs, this modulation helps achieve a more stable temperature and limits repeated starts and stops.

Why a 9,000 BTU heat pump should not be selected based solely on floor area

We regularly encounter overly simplified reasoning: a certain floor area would automatically correspond to 9,000, 12,000, or 18,000 BTU.

In the field, this shortcut can lead to a poor choice.

A room on the top floor with large south-facing windows does not have the same load as a room of identical size on the ground floor and protected from the sun. Insulation, the number of windows, ceiling height, exposure, building airtightness, and adjacent spaces must also be taken into account.

For a 9,000 BTU wall-mounted heat pump, the right goal is therefore not to choose the largest unit that fits the budget. A properly sized unit can run longer at a lower output, maintain a more consistent temperature, and better control humidity in cooling mode.

An interesting 115 V power supply, but with an MCA of 17 A and an MOCP of 25 A

The 115 V is probably the feature that will attract the most attention on this YORK unit.

The documentation for model DHP09CSB11S states:

These values are indicated directly in the YORK documentation.

The essential point is this: 115 V does not mean a portable appliance or a connection to an available 15 A outlet in the room.

With an MCA of 17 A, the electrical supply must be verified and installed according to the equipment requirements and applicable electrical standards. At AirGreen, we therefore do not select this model simply because a home has 120 V power. We check the circuit, protection, power-supply routing, and installation constraints before confirming the configuration.

This is particularly relevant during renovations in Montreal, in certain plexes, older homes, or small commercial spaces where electrical availability can become a determining factor in the project.

Heating down to -20 °C: what this value really means

YORK specifies a heating operating range of -20 °C to 24 °C for the DHP09CSB11S and an outdoor cooling range extending approximately from -18 °C to 46 °C.

However, a common misunderstanding should be avoided.

Operating at -20 °C does not mean producing 9,600 BTU/h at -20 °C.

The 9,600 BTU/h represents the nominal capacity measured under the test conditions specified for this rating. As the outdoor temperature drops, a heat pump's capacity and efficiency may decrease. For a Greater Montréal homeowner, this difference is important because temperatures below -15 °C are part of a normal winter.

We therefore consider this YORK P Series to be a solution whose suitability depends on the building and intended use. For an additional room, a space where another heating source is available, or a project where electrical constraints favor 115 V, it may meet a specific need. When looking for a heat pump intended to provide a very large share of the heating during Québec's coldest periods, we generally compare its low-temperature performance with that of recent models designed specifically for the cold climate.

Airflow, sound pressure, and room comfort

The DHP09NWB11S indoor unit offers four published airflow values:

318 / 288 / 241 / 171 CFM.

The corresponding sound pressure level ranges from 42 to 28 dB(A) depending on the speed.

The minimum level of 28 dB(A) is particularly relevant when a unit must be installed in a bedroom or office. Nevertheless, it should be remembered that the actual perceived sound level also depends on the appliance's location, the room's acoustics, the fan speed, and the required load.

The outdoor unit is rated at 53 dB(A).

In Montréal or in dense residential areas of Laval, Longueuil, Boucherville, Saint-Lambert or the North Shore, the outdoor unit's position therefore deserves as much attention as its sound rating: bedroom distance, walls that may reflect sound, neighbors, access for servicing, and snow accumulation should all be considered before drilling through the wall.

Vertical and horizontal louvers: a frequently overlooked comfort detail

Air direction is particularly important with a small wall-mounted heat pump. A 9,000 BTU unit installed in the wrong location may direct its airflow straight toward a bed, workstation, or table.

The YORK catalogue explicitly lists Auto Swing vertical in the specifications for the 115 V model.

The general feature table for the P Series also presents 3D Auto Swing, described by YORK as automatic vertical and horizontal oscillation, as well as up-down and left-right sweep functions.

This is why we indicate on our AirGreen page:

Vertical control: automatic
Horizontal control: automatic

For a previous-generation product or one from a particular batch, we nevertheless recommend confirming the exact functions of the controller supplied with the unit at the time of purchase.

Compact dimensions for a relatively discreet wall-mounted installation

The indoor unit measures approximately 31 × 11 × 8 in, or 790 × 275 × 200 mm, and its published net weight is approximately 20 lb.

The outdoor unit measures approximately 33 × 21 × 12.5 in, or 848 × 540 × 320 mm, with a net weight of approximately 63 lb.

These dimensions are useful when planning an installation in a limited space, but they do not represent the required installation clearances. Sufficient space must still be provided around the equipment for airflow, service access, connections, and normal operation.

In Quebec, outdoor installation also requires special consideration of snow. A unit placed too low or in an area where snowdrifts accumulate may become surrounded by snow or ice precisely when heating is needed.

1/4–3/8 piping: a specification to verify before reusing existing lines

The YORK DHP09CSB11S uses:

• Liquid: 1/4 in
• Gas: 3/8 in
• Drain: 5/8 in
• Maximum total piping length: 49.2 ft, or 15 m
• Maximum height difference: 33 ft, or 10 m

These values appear in the model's technical table.

This is something we systematically check when a customer wants to replace an old heat pump while keeping the existing piping. The mere fact that two copper lines are already in the wall does not mean they are automatically compatible.

The diameter, condition of the lines, refrigerant previously used, route length, accessibility, and quality of the connections must all be examined.

Which projects is this YORK P Series 9,000 BTU 115V actually suitable for?

A good example: a separate zone with a reasonable heating and cooling load

Let's consider a scenario we regularly encounter in Greater Montreal: a homeowner has a house whose main system adequately serves most rooms, but a finished office, an upstairs bedroom, or a small addition remains too hot in summer and uncomfortable during the shoulder seasons.

Installing a much larger unit can create more problems than solutions. The 9,000 BTU YORK may therefore be of interest when the load calculation confirms that its capacity range suits the room and that the 115 V electrical configuration properly meets the building's requirements.

The same reasoning can apply to a small commercial office, a room above a garage, or certain apartments where a single-zone system is sufficient.

However, we never promise that a 9,000 BTU unit will suit a room based solely on a few square feet mentioned over the phone. Sizing remains a technical step.

R-410A: a previous-generation model to consider for what it is

This YORK operates with R-410A. The charge specified by the manufacturer is approximately 24.69 oz, or 0.7 kg.

For the buyer, this mainly makes it possible to properly place the product in context. It is an older platform than the newer generations of heat pumps using refrigerants such as R-32 or R-454B.

This does not automatically make the unit unsuitable. Rather, its price, availability, efficiency, intended use, parts, warranty, and winter performance should be compared with the solutions currently available.

For a new project where the priority is the best possible performance at very low temperatures or access to current financial assistance programs, comparing it with cold-climate ENERGY STAR equipment is particularly relevant.

ENERGY STAR and LogisVert: do not assume that a heat pump automatically qualifies for a rebate

Our product sheet identifies this combination as not ENERGY STAR and not ENERGY STAR – Cold Climate.

This information has a direct impact on current programs. Hydro-Québec notably requires a cold-climate ENERGY STAR-certified heat pump for the LogisVert measures applicable to wall-mounted heat pumps.

Therefore, the YORK DHP09CSB11S / DHP09NWB11S should not be purchased on the assumption that it will receive a LogisVert rebate simply because it is a heat pump.

At AirGreen, we prefer to verify the eligibility of the specific model before signing rather than present hypothetical financial assistance that would not apply to the installed equipment.

Optional Wi-Fi with CS532AH adapter

The DRCPX wireless remote is listed as the system's standard controller.

For Wi-Fi connectivity, YORK states that a CS532AH adapter is required for the P and X Series. The catalog also specifies that the P, X, and Z Series could be controlled through the EWPE Smart app, with the adapter required for the P and X Series.

We therefore correctly classify this feature as optional Wi-Fi, not built-in Wi-Fi.

Since this platform dates back several years, a customer who now considers mobile connectivity an essential feature should confirm the adapter's availability and the app's current compatibility before installation.

Warranty: why registering the unit matters

The 2020 YORK catalog lists a standard warranty of 7 years on the compressor and 5 years on parts, followed by coverage extended to 10 years on the compressor and 10 years on parts after eligible equipment registration. Extended labor protection is also presented as a separate option.

Our AirGreen product sheet therefore presents the product coverage as 10-10-0 years, meaning compressor, parts, and no manufacturer labor warranty included in this notation, with the possibility of additional coverage.

The key point is simple: system registration should not be forgotten after installation. For a unit whose extended coverage depends on registration, this step can represent several additional years of protection.

The five mistakes we aim to avoid with this model

When a 9,000 BTU 115 V YORK P Series unit is being considered, several mistakes occur more often than others:

1. Choosing the model solely because it operates at 115 V. The 17 A MCA and 25 A MOCP require a proper electrical assessment.
2. Interpret “heating down to -20°C” as “9,600 BTUs available at -20°C.” A minimum operating temperature is not a guarantee of rated capacity at that temperature.
3. Reading “P Series 18 SEER” as the exact rating for this model. The 9,000 BTU 115 V combination is listed at 16 SEER in YORK's technical documentation.
4. Assuming that a rebate is available. This model is not identified as ENERGY STAR – Cold Climate.
5. Automatically reusing old piping. The system requires a 1/4–3/8 in. connection, with precise length and elevation-difference limits.

These details may seem secondary when comparing only the prices of several heat pumps. On a job site, however, they determine whether the installation is simple, correct, and suited to the building.

Why have this heat pump installed by AirGreen

At AirGreen Heat Pumps, Air Conditioning & Heating, we install wall-mounted systems in very different buildings throughout Montreal, Laval, Longueuil, the South Shore, the North Shore, and the greater metropolitan area.

For a YORK 9,000 BTU 115 V, our work does not simply consist of mounting two units and connecting them. We examine, among other things:

• the capacity actually required for the area;
• the available electrical supply;
• the interior wall location and air distribution;
• the outdoor unit's position;
• the length and diameter of the piping;
• condensate drainage;
• future access for maintenance and service;
• expected heating performance;
• actual eligibility for rebate programs;
• warranty and registration conditions.

This approach is particularly important with a unit such as the YORK P Series DHP09CSB11S / DHP09NWB11S, whose main appeal lies in a fairly specific combination: 9,000 BTU, 115 V power supply, compact wall-mounted design, and heating operation down to -20 °C, but without ENERGY STAR – Cold Climate certification.

For some buildings, this combination meets the need very well. For others, a newer heat pump better suited to extreme cold will be a more logical investment. Our role is to make this distinction before installation.

Are you considering the YORK P Series 9000 BTU 115 V, or would you like to compare it with a newer wall-mounted heat pump? Contact AirGreen for a quote and a recommendation tailored to your property in Montreal, Laval, Longueuil, the North Shore, or the South Shore. We can check the capacity, electrical installation, piping configuration, and options currently eligible for financial assistance before you make your decision.