YORK X Series Mini Split 23 SEER | 24000 BTU

A large wall-mounted heat pump that deserves to be evaluated based on its actual capabilities, not just the “24,000 BTU” label

The YORK X Series 23 SEER Mini Split | 24000 BTU is intended for a very different type of project than a small wall-mounted heat pump installed solely in a bedroom. With its 42-inch indoor unit, airflow of up to 706 CFM, and broad modulation range, this combination may be suitable for a large open-concept area, a floor, a small commercial space, a living room connected to a kitchen, or a residential area with a significant heating load.

At AirGreen, we pay particular attention to 24,000 BTU models because they are often chosen too quickly. Some homeowners select them based solely on floor area; others think that a larger unit will necessarily provide better comfort. In practice, the right selection depends on the building's layout, insulation, sun exposure, windows, ceilings, air circulation, and actual heating demand.

For this X Series, the model numbers are precise: DHX24NWB21S for the wall-mounted indoor unit and DHX24CSB21S for the outdoor unit. YORK clearly identifies this pair as the 24K BTU/h, 208/230 V configuration in its X Series.

However, it is important to understand a particular feature of the nomenclature. The product line is called “X Series 23 SEER”, but this figure represents the maximum performance of the family and not necessarily that of every capacity. For the DHX24 model specifically, the brochure indicates SEER 20, EER 12.5, and HSPF 10.

This is exactly the kind of detail we verify before comparing two HVAC systems. A general commercial designation never replaces reviewing the data sheet corresponding to the two model numbers actually installed.

YORK DHX24NWB21S + DHX24CSB21S: essential technical specifications

The model presented on our AirGreen page is associated with reference AHRI 8578581 and operates with R410A. The 2020 YORK brochure provides particularly detailed data for this combination.

The key specifications are:

• Indoor unit: DHX24NWB21S
• Outdoor unit: DHX24CSB21S
• Power supply: 208/230 V, 1 phase, 60 Hz
• YORK published rated cooling capacity: 22,000 BTU/h
• Cooling modulation range: 6,824 to 27,296 BTU/h
• Rated heating capacity: 23,000 BTU/h
• Heating modulation range: 6,824 to 30,708 BTU/h
• EER: 12.5
• SEER: 20 for this specific combination
• HSPF: 10
• MCA: 20 A
• MOCP/MOP: 30 A
• Indoor airflow: 706 / 647 / 588 / 530 CFM
• Indoor sound pressure: 48 / 44 / 40 / 36 dB(A)
• Outdoor sound pressure: 59 dB(A)
• Piping: 1/4 in liquid and 5/8 in gas
• Drain: 5/8 in
• Maximum piping length: 82 ft / 25 m
• Maximum elevation difference: 33 ft / 10 m
• Heating range: down to -20 °C
• Cooling range: down to -18 °C outdoor low-temperature side
• Wi-Fi available with CS532AH adapter.

These figures provide a much more useful picture of the unit’s potential behavior than a simple “24,000 BTU.”

Why does YORK call it 24,000 BTU when the brochure indicates 22,000 BTU nominal cooling capacity?

This difference deserves a clear explanation.

The DHX24 belongs to YORK’s 24K commercial category, but the nominal cooling capacity listed in the manufacturer’s table is 22,000 BTU/h. However, its maximum modulated capacity reaches 27,296 BTU/h in cooling mode. In heating mode, it is nominally 23,000 BTU/h and can reach 30,708 BTU/h under the conditions defined by the manufacturer.

This does not mean there is a product error. HVAC equipment families are commonly grouped by capacity classes, while the certified data for a specific combination may differ from the round value used in its commercial designation.

At AirGreen, when we size a wall-mounted heat pump in Montreal, Laval, Longueuil, on the North Shore or the South Shore, we therefore consider the certified capacity and its modulation range, not just the number shown in the product name.

Modulation that genuinely changes the unit’s behavior

The YORK X Series 24K’s modulation range is noteworthy because it can drop to approximately 6,824 BTU/h while also being able to significantly exceed its nominal capacity at a given moment.

A properly sized Inverter unit therefore does not constantly operate at 22,000 or 24,000 BTU. As the room approaches the desired temperature, the compressor can reduce its output to better track the load.

YORK explains that its mini-split systems specifically use this refrigerant flow modulation to adjust capacity to the zone’s demand. This technology also helps limit the temperature fluctuations associated with systems that constantly start and stop.

In a large open-concept area in Longueuil, for example, demand can be high on a July afternoon when the sun shines directly through several windows, then drop sharply after sunset. The advantage of the Inverter compressor is precisely that it does not handle these two situations in the same way.

A maximum airflow of 706 CFM: the positioning of the indoor module becomes crucial

The DHX24NWB21S provides four airflow levels: 706, 647, 588 and 530 CFM. YORK indicates corresponding sound levels of 48, 44, 40 and 36 dB(A).

With airflow of this magnitude, the location of the indoor unit must be carefully considered.

We avoid sending the airflow from a 24K unit directly toward a sofa, dining table, or workstation located a short distance away whenever possible. The goal is instead to take advantage of the room's length so that the air gradually mixes before returning to the evaporator.

In our HVAC projects in Montreal and the Montérégie, a common mistake is to select the only wall where installation seems easy without analyzing the airflow path. The system can then produce enough BTUs while creating an uncomfortable zone directly in front of the unit and a less uniform temperature at the other end.

A 42-inch indoor unit designed to move a lot of air

The indoor module measures 42 × 13 × 10 in, or approximately 1,078 × 325 × 246 mm. Its net weight is approximately 38 lb.

The DHX24CSB21S outdoor unit is larger: approximately 39 × 31 × 17 in, or 980 × 790 × 427 mm. YORK indicates a net weight of approximately 142 lb and an outdoor sound pressure level of 59 dB(A).

These dimensions have a direct impact on a heat pump installation.

On a narrow lot in Montreal, a condo balcony in Laval, or a home's side yard on the South Shore, sufficient space must be allowed for clearances, future servicing of the unit, air discharge, and snow management in winter.

The choice of outdoor support also matters. The unit must not be positioned where ice, snow, or water from a roof could regularly fall onto the appliance.

Heating Down to -20 °C: The Minimum Temperature Does Not Tell the Whole Story

The YORK brochure indicates a heating operating range of -20 °C to 24 °C for the DHX24CSB21S.

Our AirGreen specifications also provide additional low-temperature capacity data: approximately 20,000 BTU at -8 °C, 19,800 BTU at -15 °C, and a displayed maximum value of 11,000 BTU at -20 °C.

These figures show why we never evaluate a heat pump solely based on the statement “heats down to -20 °C.”

The more important question is: how much heating capacity remains when it is actually cold?

A unit may continue operating at -20 °C while providing less capacity than at 0 °C. If the home’s heat loss exceeds the heat pump’s output at that temperature, a supplemental heating source must take over or assist with heating.

This distinction is particularly important for homeowners in Laval, Terrebonne, Blainville, Repentigny, Longueuil, Boucherville, and other areas of Greater Montreal, where temperatures can drop well below -15 °C.

1/4 in. – 5/8 in.: Piping to Confirm Before Any Replacement

The DHX24 uses a 1/4 in. liquid line and a 5/8 in. gas line. The brochure allows for a maximum length of 82 feet and a maximum elevation difference of 33 feet.

The 5/8 in. diameter on the gas side is an important consideration when replacing a unit.

We often encounter properties where the old unit used different piping. A homeowner may then want to keep the existing lines to reduce the amount of work. This is not automatically possible.

A 24,000 BTU heat pump from another manufacturer does not necessarily use the same diameters. We therefore check the existing lines before confirming that they can be reused.

The savings from keeping unsuitable piping are never worth the potential problems with refrigerant flow, oil return, and compressor operation.

MCA 20 A and MOP 30 A: What This Means for the Electrical Circuit

The YORK X Series 24K operates on a 208/230 V single-phase power supply. Its manufacturer’s specifications indicate an MCA of 20 A and a maximum protection rating MOCP of 30 A.

MCA is the minimum circuit ampacity to consider when supplying power to the equipment. MOP/MOCP, meanwhile, determines the maximum permitted overcurrent protection according to the manufacturer’s data.

During an AirGreen installation, we therefore do not limit ourselves to asking whether the customer “has 220 V.” The circuit type, its rating, its breaker, and the nameplate specifications of the actual unit delivered must match.

This verification becomes particularly important in some older homes in Montréal or Laval, where several electrical additions may have been made over the years.

Automatic Louvers and Airflow Control

YORK’s X Series documentation indicates several functions related to air distribution, including automatic vertical and horizontal movement, according to the range’s function chart.

Our AirGreen product sheet therefore correctly states:

Vertical louver: automatic
Horizontal louver: automatic

For a unit capable of exceeding 700 CFM, this feature is especially useful.

Horizontal movement can help distribute air throughout an open area rather than concentrating the entire airflow in one direction. Vertical movement makes it easier to adjust air distribution depending on whether the system is being used for cooling or heating.

However, adjusting the louvers cannot correct poor placement. If a heat pump is installed in a hallway with the expectation that it will heat three bedrooms evenly while their doors remain closed, the problem is not the remote-control setting: it is the project design.

Optional Wi-Fi with the CS532AH adapter

The X Series can be controlled through the EWPE Smart App, but connectivity requires the CS532AH adapter for the P and X Series. YORK also specifies that the DRCPX wireless remote control comes standard with the X Series.

We like to clarify this distinction before installation because “Wi-Fi compatible” and “built-in Wi-Fi” do not mean the same thing.

A homeowner who wants to schedule or control their unit remotely must plan for the necessary module rather than assume that the function is already installed in the wall-mounted air conditioner.

Construction, Defrosting, and Practical Features of the X Series

YORK presents the X Series as an Inverter heat pump equipped with a rugged steel chassis, a corrosion-resistant coating, and quiet operation. The manufacturer also mentions a demand-initiated defrost strategy to limit unnecessary energy consumption associated with defrosting.

Defrosting is particularly relevant in Québec.

When the outdoor unit operates in heating mode, the outdoor coil may accumulate frost. The system must periodically reverse its cycle to clear the coil. The frequency depends on outdoor conditions, particularly temperature and humidity.

A heat pump that defrosts in winter does not necessarily indicate a problem. However, excessive ice accumulation that does not disappear, abnormally frequent cycles, or a unit with obstructed winter drainage warrant an inspection.

What we verify at AirGreen before recommending this 24K YORK in Montréal, Laval, Longueuil, the North Shore, or the South Shore

A 24K capacity is not a shortcut to avoid a load calculation

A large heat pump does not compensate for poor selection.

For example, we encounter open-plan ground floors where a capacity in this category makes perfect sense: large area, numerous windows, an open kitchen, and strong solar exposure. In other properties, the same unit would be oversized despite a similar area because the building’s insulation and orientation are different.

We therefore analyze the room as a whole: building envelope, windows, orientation, floors, air volume, communication between zones, and the system’s actual use.

This is particularly relevant for a model whose range goes down to approximately 6,824 BTU/h. This modulation provides flexibility, but it does not make oversizing inconsequential.

An important nuance regarding ENERGY STAR

The AirGreen specification sheet currently provided classifies this model as ENERGY STAR: No and ENERGY STAR Cold Climate: No.

The November 2020 YORK brochure nevertheless contains a different note: it states that all models in this series presented in the table were ENERGY STAR, except the 18K DHX18 models.

This difference illustrates why we always distinguish between a former manufacturer certification and a device’s current eligibility for a Québec program.

For a grant application in 2026, we recommend checking the exact combination against the current lists and criteria rather than relying on the logo appearing in a 2020 brochure.

The attached brochure is indeed dated November 2020.

SEER 23 or SEER 20: once again, the two figures do not describe the same thing

The family title indicates 23 SEER because the X Series reaches up to 23 SEER in certain capacities. The brochure also specifies that the X Series is a range “up to 23 SEER.”

For the DHX24NWB21S + DHX24CSB21S, however, the published rating is 20 SEER.

For us, this is not an administrative detail. When a customer compares a YORK heat pump with another brand, the performance of the exact combinations must be compared; otherwise, two products may appear identical on paper even though they are not.

The same caution applies to the newer SEER2 and HSPF2 ratings: an older brochure using SEER/HSPF should not be arbitrarily converted into SEER2/HSPF2 values.

Warranty: understanding the difference between the standard warranty and the registered extended warranty

Our AirGreen listing presents this model with a warranty of 10 years on the compressor, 10 years on parts, 0 years on labor, with the possibility of additional coverage.

YORK documentation explains that the standard warranty for this generation was 7 years on the compressor and 5 years on parts, and that eligible residential registration allowed it to be extended to 10 years on the compressor and 10 years on parts. A 10-year labor warranty option was also available subject to additional conditions.

We therefore always recommend keeping the invoice, serial numbers, and registration confirmation after an HVAC installation.

Maintenance remains important for a large wall-mounted unit

A unit capable of moving 706 CFM depends directly on the cleanliness of its heat exchanger, filters, and blower wheel.

Over time, dust can accumulate on the blower wheel. The owner may then gradually notice reduced airflow, a different sound level, or less even distribution throughout the room.

The condensate drain must also remain clear. In summer, a unit of this capacity can remove a significant amount of moisture from the air. A clogged or improperly sloped drain can cause water to leak indoors.

Professional HVAC maintenance therefore does not consist solely of rinsing the visible filters. Depending on the system’s condition, the evaporator, blower wheel, condensate pan and drainage may require a more thorough inspection and cleaning.

Why Have This YORK Installed by AirGreen

The YORK Series X 24K has interesting features, but its actual performance depends directly on the installation.

At AirGreen, our work does not stop at mounting the evaporator on the wall. We must verify the capacity, the piping route, the diameter 1/4–5/8, the drain, the electrical supply, the condenser location, the airflow path and the customer’s expectations for winter heating.

We work daily in the various types of buildings found in Montreal, Laval, Longueuil, on the North Shore, the South Shore and in Montérégie: single-family homes, plexes, condos, commercial premises and properties where available space can sometimes make outdoor installation more difficult.

For this YORK Series X Mini Split, we primarily note that it is a 24K-class unit offering a published capacity of 22,000 BTU/h in cooling and 23,000 BTU/h in heating, modulation reaching 27,296 BTU/h in cooling and 30,708 BTU/h in heating, a 208/230 V power supply, an MCA of 20 A, maximum protection of 30 A and 1/4–5/8 piping.

Contact AirGreen to confirm whether the YORK Series X 24K is truly suitable for your space

The YORK Series X 23 SEER | 24000 BTU Mini Split can be a very interesting option for a large area when properly sized. Its inverter technology, modulation range, high airflow, automatic louvers, heating down to -20 °C and optional Wi-Fi give it appreciable versatility.

But the right question is never simply “Is a 24,000 BTU unit large enough?” Instead, we seek to determine what capacity your building actually requires and how to install the unit to use that capacity properly.

Contact AirGreen for a quote or an assessment of your ductless heat pump project in Montreal, Laval, Longueuil, on the North Shore or South Shore. We can verify whether this YORK Series X matches your heating load, electrical installation and heating expectations before you finalize your choice.