VRF (Variable Refrigerant Flow) indoor units come in a wide variety of types to suit different installation and design needs, with specifications that vary by manufacturer and model. Common specifications include cooling and heating capacity, airflow rates, sound pressure levels, and physical dimensions.

Common types of VRF indoor units

Wall-mounted units: These are a space-saving and aesthetically simple option, often used in smaller rooms. Specifications to consider include the capacity, multi-speed fan control, and noise level, which is typically low.

Cassette units (1-way, 2-way, and 4-way): Cassettes are designed to be installed in a false or dropped ceiling, with only the grille visible.

1-way cassettes: Ideal for long, narrow spaces, as they direct airflow from one side. They are compact and often feature simple installation and maintenance.

2-way and 4-way cassettes: Offer broader, more uniform air distribution. 4-way cassettes provide 360-degree airflow, making them suitable for larger, open areas. Some models include features like independent vane control and advanced air purification.

Ducted units: Concealed within a ceiling void, these units distribute conditioned air through a network of ducts to different vents in a room. They are categorized by the static pressure they can generate to move air through the ductwork.

Low static pressure ducted: Designed for shorter, less complex duct runs and are generally quieter.

Medium static pressure ducted: Capable of more complex ducting, allowing for conditioning of larger areas.

High static pressure ducted: Used for long duct runs and applications that require a great deal of pressure to deliver air, such as in large commercial spaces.

Floor-standing units: This type sits directly on the floor and is suitable for rooms with limited wall or ceiling space. They are often chosen for their powerful, long-range airflow.

Ceiling-suspended units: These units are mounted directly to the ceiling and do not require a false ceiling, making them a good option when ceiling voids are not available.

Console units: Similar to floor-standing units but with a more compact design for placement against a wall, typically at floor level. Many are available with advanced filtration systems and sleek designs.

Key specifications for evaluation

Capacity: Measured in kilowatts (kW) or British Thermal Units per hour (BTU/h), capacity indicates the unit’s heating and cooling power. It must be appropriately sized to the room’s load requirements to ensure energy efficiency and comfort.

Airflow rate: Measured in cubic meters per minute (m³/min) or cubic feet per minute (cfm), the airflow rate indicates how much air the unit can move. This is a critical factor for effective temperature distribution and overall comfort.

Sound pressure level: Measured in decibels (dB), this indicates how quietly the unit operates. For noise-sensitive environments like offices and residential spaces, a low sound level is a crucial specification.

Dimensions and weight: The physical size and weight of the unit determine where it can be installed, especially for concealed models that must fit within specific architectural limitations.

External static pressure (for ducted units): Measured in pascals (Pa), this is the pressure the fan can generate to overcome the resistance of ductwork. High-static pressure units are required for longer and more complex duct runs.

Control options: Modern units come with a range of control features, including wireless or wired controllers, Wi-Fi connectivity for app control, and advanced scheduling.

Energy efficiency ratings: High EER (Energy Efficiency Ratio) and COP (Coefficient of Performance) ratings indicate better energy performance, which translates to lower operating costs.

Special features: Some units include extras like air purification filters (HEPA, ionizers), automatic vane control, automatic restart, and built-in condensate pumps.