Zephyr CB25 R454B ZE-24CB25 Wall-Mounted Heat Pump – 24,000 BTU

A 24,000 BTU wall-mounted heat pump designed for large spaces, heating down to -30 °C, and stable daily comfort

The Zephyr CB25 R454B ZE-24CB25 Wall-Mounted Heat Pump is aimed at owners looking for a powerful, modern HVAC solution well adapted to the realities of the Quebec climate. With its capacity of 24,000 BTU in cooling and 24,000 BTU in heating at 8.3 °C, this model is designed for large residential spaces, open areas, spacious condos, light commercial spaces, or zones difficult to balance in temperature.

At AirGreen, we recommend this type of device when a customer needs a wall-mounted heat pump capable of providing a good power reserve while maintaining a pleasant and more consistent indoor temperature. Whether in Montreal, Laval, Longueuil, on the South Shore or the North Shore, a machine of this capacity must be chosen carefully: it can offer excellent comfort, but only if it is properly sized, well positioned, and correctly installed.

The Zephyr CB25 series stands out for several important features: its refrigerant R454B, its Energy Star V6.1 certification, its heating operation down to -30 °C, its variable frequency technology, its 4D mode, its high airflow, and its solid technical specifications for a 24,000 BTU wall-mounted heat pump. The technical data below come from the provided Zephyr CB25 brochure, notably the datasheet for the ZE-24CB25 model.

1. A 24,000 BTU wall-mounted heat pump for demanding projects

The Zephyr CB25 R454B ZE-24CB25 is a wall-mounted heat pump designed to meet greater needs than a simple closed room. With a capacity of 24,000 BTU, it can suit a large open area, a ground floor, a light commercial space, a large living room, a room with a higher ceiling, or a zone where heating and cooling loads are more significant.

However, at AirGreen, we always emphasize one essential point: 24,000 BTU does not automatically mean “best choice” for every project. An overly powerful heat pump can reach the temperature too quickly in summer, reduce dehumidification time, and create uneven comfort. Conversely, an undersized unit will have to run almost continuously and might struggle during periods of intense cold or prolonged heat.

That’s why we always analyze the area, insulation, ceiling height, window orientation, sunlight exposure, room layout, available clearances, and the location of the outdoor unit. A heat pump like the ZE-24CB25 can offer excellent performance, but it must be smartly integrated into the building.

2. Important technical specifications of the ZE-24CB25

Here are the main details to remember for the Zephyr CB25 R454B ZE-24CB25 Wall-Mounted Heat Pump:

• Brand: Zephyr
• Series: CB25
• Model: ZE-24CB25
• Type: wall-mounted heat pump
• Refrigerant: R454B
• Cooling capacity at 35 °C: 24,000 BTU/h
• Heating capacity at 8.3 °C: 24,000 BTU/h
• SEER2: 22.5
• HSPF2 IV: 9.5
• EER2: 12.25
• Heating COP at 8.3 °C: 3.35 W/W
• COP at -15 °C: 2.0 W/W
• Nominal heating at -8.3 °C: 22,000 BTU/h
• Maximum heating at -15 °C: 19,200 BTU/h
• Maximum heating at -20 °C: 14,100 BTU/h
• Maximum heating at -25 °C: 11,700 BTU/h
• Energy Star V6.1: yes
• Indoor air flow: 441 to 706 CFM
• Indoor sound pressure: 50 / 48 / 43 / 41 / 39 dB(A)
• Outdoor sound pressure: 61 dB(A)
• Voltage: 208V / 230V, 60Hz, 1 phase
• Nominal cooling current: 8.7 A
• Nominal heating current: 9.3 A
• MCA: 22 A
• MOP: 25 A
• Required communication wire: 4/14 copper multi-strand 600V
• Liquid piping: 3/8 in
• Gas piping: 5/8 in
• Minimum-maximum piping length: 10 to 98 ft
• Maximum elevation difference: 50 ft
• Precharge length: 25 ft
• Compressor: GMCC rotary
• Expansion device: EEV
• Indoor DC motor: yes
• Outdoor DC motor: yes
• Indoor unit dimensions L x D x H: 42.06 x 9.06 x 12.63 in
• Outdoor unit dimensions L x D x H: 35.38 x 13.50 x 29.50 in
• Cooling range: -15 °C to 48 °C
• Heating range: -30 °C to 24 °C
• Zephyr basic warranty: 10 years parts
• Labor warranty: available depending on the offer and distributor

An important point: the brochure states that the series can reach up to 25 SEER2 / 11 HSPF2, but for the specific model ZE-24CB25, the indicated values are 22.5 SEER2 and 9.5 HSPF2. This is a crucial distinction, as performance varies depending on the unit’s capacity.

3. The R454B refrigerant: a new generation for HVAC installations

The ZE-24CB25 model operates with R454B refrigerant, a new generation refrigerant increasingly used in modern HVAC equipment. For a customer, the type of refrigerant may seem secondary, but it directly influences the design of the unit, installation practices, and technical requirements.

With the R454B, the installation must be carried out with precision. Pipe lengths, fittings, vacuum pulling, leak tests, adherence to line diameters, and electrical compliance become even more important. A modern heat pump does not tolerate a sloppy installation.

At AirGreen, we pay close attention to these details, especially when it comes to a high-capacity unit like a 24,000 BTU. Poor installation can reduce performance, increase noise, cause drainage problems, or harm the compressor’s durability.

4. Heating down to -30 °C: what this means in Quebec

The brochure states that the Zephyr heat pump can provide optimal heating down to an outdoor temperature of -30 °C. For Quebec, this is an important point. Winters in Montreal, Laval, Longueuil, on the South Shore and North Shore can bring long periods of cold, and a wall-mounted heat pump must be able to operate in tough conditions.

However, it is important to understand the numbers well. The ZE-24CB25 offers:

• 22,000 BTU/h at -8.3 °C
• 19,200 BTU/h at -15 °C
• 14,100 BTU/h at -20 °C
• 11,700 BTU/h at -25 °C

These values show that the unit maintains a good capacity at low temperatures, but like all heat pumps, its capacity decreases as the cold intensifies. In a well-insulated house, this performance can cover a large part of the heating needs. In an older house, with many windows or exposed to wind, supplementary heating may still be necessary on the coldest days.

At AirGreen, we always explain this reality before installation. A high-performance wall-mounted heat pump can significantly reduce the use of traditional electric heating, but it must be chosen according to the actual needs of the building.

5. Indoor comfort: 4D mode, automatic oscillation, and Inverter technology

The brochure highlights several features designed to improve daily comfort. The ZE-24CB25 uses variable frequency technology, often called Inverter, which allows the heat pump to adjust its power in real time. This helps limit temperature fluctuations and reduce energy consumption.

The 4D mode and automatic oscillation help distribute air better throughout the room. This feature is especially useful for large spaces, as it helps avoid cold spots or overly warm areas. In an open area, good air movement can make a big difference between simply reaching a temperature and truly comfortable conditions.

The brochure also mentions several practical features:

• Night mode
• Silent mode
• iFeel mode
• Quick start
• 24-hour timer
• Automatic defrost
• Automatic cleaning
• Turbo function
• Wireless LED remote control
• LED dimmer
• 5 indoor fan speeds
• Diffuser position memory
• Automatic heating 8 °C / 46 °F
• Two-sided drain
• Reversible drain pipe
• Outdoor base heating
• Compressor heating
• Fireproof electrical box
• Auto-adaptive voltage technology

These features do not replace a good installation, but they improve the user experience. A customer can better control comfort, reduce drafts, improve air distribution, and adjust operation according to the season.

6. Installation: technical details to verify before work

A 24,000 BTU wall-mounted heat pump is not installed like a small 9,000 or 12,000 BTU unit. The ZE-24CB25 requires serious planning, especially due to its capacity, electrical supply, and piping.

Indoor unit location

The indoor unit measures approximately 42.06 x 9.06 x 12.63 in in L x D x H format. It is therefore wider than a small wall unit. You need to plan for a sufficiently clear wall, a good installation height, and an orientation that allows air to circulate efficiently.

In homes in Montreal or Longueuil, we often encounter constraints such as brick walls, plaster ceilings, narrow partitions, nearby windows, or exposed beams. In Laval, on the North Shore or South Shore, large open spaces sometimes allow for better air distribution, but it is still important to avoid blowing air directly on occupants for long periods.

Outdoor Unit Location

The outdoor unit measures approximately 35.38 x 13.50 x 29.50 in in L x D x H format. It must be installed in a stable, accessible, and well-ventilated location. The indicated outdoor noise level is 61 dB(A), which should be considered in denser areas or near neighbors.

The outdoor unit must also be protected against snow accumulation, roof water, ice, and obstacles that can block airflow. Poor outdoor placement can reduce performance, increase defrost cycles, and complicate maintenance.

3/8 - 5/8 in Piping

The ZE-24CB25 uses a liquid line of 3/8 in and a gas line of 5/8 in. This is very important information, especially when replacing an old heat pump.

Never assume existing lines are compatible. At AirGreen, we always check the diameter, condition of the lines, old refrigerant, length, routing, insulation, and accessibility. In many cases, replacing the lines is the best decision to protect the performance and durability of the new system.

208V / 230V Power Supply

The technical sheet specifies a power supply of 208V / 230V, 60Hz, single phase, with a MCA of 22 A and a MOP of 25 A. This means an appropriate electrical circuit with proper protection must be planned.

In older homes, the electrical panel may already be fully loaded. Before confirming installation, it is necessary to check the available space, wire gauge, circuit breaker, distance to the outdoor unit, and connection compliance.

7. Energy Performance and Consumption

The ZE-24CB25 features a SEER2 of 22.5, a HSPF2 of 9.5, an EER2 of 12.25, and a COP of 3.35 W/W at 8.3 °C. These figures indicate a high-performance heat pump for a large-capacity wall unit.

The SEER2 represents seasonal cooling efficiency. The higher it is, the more efficient the unit is during the cooling season. The HSPF2 relates to heating efficiency over a season. The EER2 provides an efficiency indication under specific cooling conditions. The COP indicates the ratio between thermal energy produced and electricity consumed.

For a customer, the goal is not to memorize every indicator. The important thing is to understand that energy performance depends as much on the machine as on the installation and actual use. A well-placed, well-calibrated, and well-maintained heat pump will always deliver better results than a high-performance machine installed without analysis.

8. Maintenance and durability of the Zephyr CB25 heat pump

A wall-mounted heat pump like the Zephyr CB25 ZE-24CB25 should be maintained regularly to preserve its efficiency, noise level, and air quality.

We especially recommend:

• Clean the filters regularly
• Ensure the condensation drain remains clear
• Keep the outdoor unit free of leaves, dust, snow, and ice
• Monitor for any unusual noises
• Have the unit inspected if performance decreases
• Clean the indoor heat exchanger when necessary
• Check clearances around the outdoor unit before winter
• Schedule professional maintenance based on usage

The brochure mentions an automatic cleaning function, an automatic defrost, a heated chassis for the outdoor base, and compressor heating. These features help the unit perform better, but they do not replace proper maintenance.

9. Mistakes to avoid before buying a 24,000 BTU heat pump

The most common mistakes don’t always come from the choice of brand. They often come from a poor project assessment.

Here are the mistakes to avoid:

• Choosing a 24,000 BTU simply because it seems more powerful
• Neglecting the analysis of area and insulation
• Forgetting to check the electrical panel
• Assuming the old piping is compatible
• Installing the indoor unit in a convenient but ineffective location for air distribution
• Installing the outdoor unit too close to a wall, fence, or neighbor
• Underestimating the importance of drainage
• Ignoring future access for maintenance
• Comparing only price without comparing installation quality
• Not validating low-temperature performance

At AirGreen, we prefer to clarify these elements before work begins. This helps avoid unpleasant surprises, costly adjustments, and unrealistic expectations.

10. Why choose AirGreen to install the ZE-24CB25

AirGreen is a company specialized in HVAC, active in the installation, maintenance, and repair of wall-mounted, central, and multi-zone heat pumps. We regularly operate in Montreal, Laval, Longueuil, on the South Shore, the North Shore, and the greater metropolitan area.

By choosing AirGreen to install a Zephyr CB25 R454B ZE-24CB25, you benefit from a comprehensive approach:

• Clear evaluation before work begins
• Verification of proper sizing
• Analysis of indoor and outdoor placement
• Electrical validation
• Required piping inspection
• Installation compliant with good HVAC practices
• Honest explanation of low-temperature performance
• Structured after-sales service
• Support for maintenance and use
• Local expertise in Quebec buildings

The ZE-24CB25 is a powerful, efficient, and well-equipped wall-mounted heat pump. It can be an excellent solution for customers who want to cool and heat a large space with a modern unit using R454B, capable of operating down to -30 °C in heating mode.

But as with any HVAC system, the success of the project depends on the installation. The right model, in the right place, with the right piping, the right electrical circuit, and proper clearances will deliver a much more reliable and comfortable result.

To get a clear quote, compare this model with other wall-mounted heat pumps or plan an installation in Montreal, Laval, Longueuil, on the South Shore or the North Shore, contact AirGreen. Our team will help you choose a solution suited to your building, budget, and comfort goals.