Cooper&Hunter CHML-U14RK2-NG — Multi-Split Outdoor Unit

The Cooper&Hunter CHML-U14RK2-NG is a compact inverter outdoor unit from the Nordic Multi Light R32 NG series, designed to connect 1–2 compatible indoor units. With 4.10 kW cooling capacity and 4.40 kW heating capacity, it is an excellent solution for apartments, private homes, offices and other spaces requiring independent climate control in one or two zones.

The unit uses R32 refrigerant, Stable Frequency Control technology and Intelligent Preheating frost protection for reliable year-round operation. Current Cooper&Hunter documentation confirms the model-specific specifications below.

Key Features

Efficient Cooling for 1–2 Zones– With a nominal cooling capacity of 4.10 kW, the CHML-U14RK2-NG is designed for multi-zone climate control using one or two compatible indoor units.

The configuration is particularly convenient for:

• Living room + bedroom
• Two bedrooms
• Living room + office
• Small apartment with two climate zones
• Small office or commercial space

A cooling capacity of 4.10 kW is approximately equivalent to 14,000 BTU/h and can generally be considered for an area of around 35–45 m², depending on insulation, ceiling height, glazing, solar exposure and internal heat gains.

Heating Capacity — 4.40 kW– The unit provides 4.40 kW of nominal heating capacity, allowing the system to operate as a heating and cooling solution throughout the year. The manufacturer’s detailed specification gives an operating range of −22°C to +24°C in heating mode. This makes the CHML-U14RK2-NG suitable for regions where winter temperatures can fall significantly below freezing.

 Inverter Technology & Stable Frequency Control– The inverter compressor continuously adjusts its output according to the current thermal demand. Stable Frequency Control enables smooth and stable operation at ultra-low compressor frequencies down to 15 Hz.

Key benefits:

• Stable indoor temperature
• Efficient operation at partial load
• Smooth compressor modulation
• Reduced start/stop cycling
• Lower mechanical stress
• Improved comfort
• Efficient electricity consumption

The manufacturer specifies a system operating capacity range of 50–150% of the outdoor unit’s rated capacity, providing additional flexibility when selecting compatible indoor units.

 R32 Refrigerant– The CHML-U14RK2-NG uses modern R32 refrigerant. The current manufacturer specification lists a factory refrigerant charge of 0.75 kg and an additional charge of 20 g/m when required. The standard pipe length without additional refrigerant is 10 m. R32 is widely used in modern inverter air-conditioning systems and offers a lower global warming potential than many older refrigerants.

Noise Analysis Technology– The unit incorporates Noise Analysis Technology, which is designed to optimize system operation and minimize unnecessary operating noise. The specified outdoor sound pressure level is approximately 52 dB(A). For residential applications, the outdoor unit should still be positioned with consideration for bedrooms, balconies and neighboring properties. Correct mounting and vibration isolation can further improve acoustic comfort.

 Intelligent Preheating Frost Protection– The Nordic Multi Light R32 NG series uses an Intelligent Preheating automatic anti-icing system Instead of relying exclusively on a fixed time-based defrost cycle, the system initiates defrosting when it is actually required. According to Cooper&Hunter, this approach helps reduce unnecessary defrost cycles and associated energy losses. This is particularly useful when the system is operated in heating mode during cold and humid weather.

Wide Operating Temperature Range– The manufacturer specifies:

Cooling: −15°C to +43°C
Heating: −22°C to +24°C

Cooper&Hunter also describes the Nordic Multi Light R32 NG platform as having a wider effective-operation range from −20°C for heating to +48°C for cooling. For the product card, however, the model-specific technical table values of −15…+43°C / −22…+24°C are preferable.

Flexible Piping Configuration– The CHML-U14RK2-NG allows a total refrigerant pipe length of up to 40 m, with a maximum individual branch length of 20 m and a maximum height difference of 15 m.

These limits should be observed when designing the system to maintain correct refrigerant circulation and reliable performance.

 Recommended Application– The 4.10 kW cooling capacity makes the CHML-U14RK2-NG suitable for approximately 35–45 m² under typical conditions.

However, the actual required capacity depends on:

• Total floor area
• Individual room sizes
• Ceiling height
• Insulation quality
• Window area
• Solar exposure
• Number of occupants
• Internal heat sources
• Desired indoor temperature

For a multi-split system, it is particularly important to calculate the requirements of each individual room, rather than selecting the outdoor unit solely according to total floor area.

 One Outdoor Unit — Two Indoor Units– A key advantage of the CHML-U14RK2-NG is its ability to connect up to two compatible indoor units.

This allows separate climate zones while requiring only one outdoor unit, helping to:

• Reduce the number of outdoor units
• Save exterior installation space
• Create a cleaner building facade
• Control rooms independently
• Simplify multi-room climate control

The selected indoor units must be compatible with the CHML-U14RK2-NG and comply with the manufacturer’s approved combinations.

Reliable Operation

The model includes several technologies designed for stable operation:

• Stable Frequency Control
• Noise Analysis Technology
• Intelligent Preheating
• Automatic frost protection
• Auto Restart
• Self-Diagnosis
• Voltage protection
• Electronic expansion valve
• Anti-corrosion protection

The manufacturer also specifies safe start-up from 96 to 260 V, providing additional protection against unstable mains voltage.

 Important Installation Information

The CHML-U14RK2-NG is an outdoor unit only and requires one or two compatible indoor units to form a complete multi-split system.

Before purchasing, verify:

1. Compatibility of the selected indoor unit(s).
2. Combined indoor-unit capacity.
3. Maximum 40 m total piping.
4. Maximum 20 m individual branch length.
5. Maximum 15 m height difference.
6. Correct R32 refrigerant piping.
7. Required additional refrigerant charge.
8. Electrical requirements and installation clearances.

Installation should be carried out by a qualified HVAC technician.

Specification	Value
Model	CHML-U14RK2-NG
Series	Nordic Multi Light R32 NG
Type	Multi-Split Inverter Outdoor Unit
Compatible Indoor Units	1–2
Cooling Capacity	4.10 kW
Heating Capacity	4.40 kW
Nominal Power Consumption – Cooling	1.10 kW
Nominal Power Consumption – Heating	0.97 kW
SEER	7.20
SCOP	4.20
Energy Efficiency Class	A++ / A+
Outdoor Airflow	2,300 m³/h
Sound Pressure Level	52 dB(A)
Refrigerant	R32
Factory Refrigerant Charge	0.75 kg
Additional Refrigerant	20 g/m
Standard Pipe Length Without Additional Charge	10 m
Power Supply	220–240 V / 50 Hz / 1 Phase
Cooling Operating Range	−15°C to +43°C
Heating Operating Range	−22°C to +24°C
Maximum Total Pipe Length	40 m
Maximum Pipe Length to One Indoor Unit	20 m
Maximum Height Difference	15 m
Outdoor Unit Dimensions (W × D × H)	822 × 300 × 550 mm
Packed Dimensions	869 × 395 × 594 mm
Outdoor Unit Net / Gross Weight	30 / 32.5 kg
Compressor Technology	Inverter
Expansion Device	Electronic Expansion Valve (EEV)