The Haier Cassette 620 3.5 kW Kit (indoor: AB35S2SC2FA / outdoor: 1U35S2SM1FA-2) is a 4-way ceiling cassette air conditioner and heat pump for light commercial and larger domestic applications — open-plan offices, retail spaces, classrooms and reception areas up to approximately 35–40 m². Sharing the identical 570 × 570 × 260mm body and 620 × 620mm panel as the 2.5 kW model, it delivers 3.5 kW cooling and 4.0 kW heating at the same compact ceiling footprint — with no installation complexity penalty for stepping up in capacity. Minimum sound pressure is just 27 dB(A). Airflow is delivered across 4 independently controllable directions. Rated SEER 6.1 A++ cooling and SCOP 3.8 A heating. Integrated hOn Wi-Fi, UVC sterilisation, fresh air inlet with on/off card and a black panel option (while stocks last) are included as standard. R32 refrigerant. Kit includes indoor cassette, panel, outdoor condensing unit and wall controller.
3.5 kW
Cooling Output
4.0 kW
Heating Output
A++
SEER 6.1 — Cooling
A
SCOP 3.8 — Heating
27 dB(A)
Min Sound Level
4-way
Independent Airflow
⚠ F-Gas Regulation: Installation of this air conditioning system must be carried out by an F-Gas certified engineer (REFCOM, QUIDOS or VERITAS registered). Purchase requires a valid F-Gas certificate. Proof of certification must be supplied at the time of order.
Cassette 620 Range — Select Your Output
Size
Indoor
Outdoor
Cooling
Heating
SEER
SCOP
Min Sound
Max Pipe
R32 Charge
2.5 kW
AB25S2SC2FA
1U25S2SM1FA-2
2.5 kW
3.23 kW
SEER 6.1 A++
SCOP 4.0 A+
28 dB(A)
20 m
0.63 kg
3.5 kW ✓
AB35S2SC2FA
1U35S2SM1FA-2
3.5 kW
4.00 kW
SEER 6.1 A++
SCOP 3.8 A
28 dB(A)
20 m
0.78 kg
5.0 kW
AB50S2SC2FA
1U50S2SJ2FA-2
5.0 kW
5.50 kW
SEER 6.1 A++
SCOP 4.0 A+
35 dB(A)
25 m
1.10 kg
All models: 1Ph/220–240V/50–60Hz, R32, 570×570×260mm body, 620×620mm panel, 4-way independent airflow, 28 dB(A) min. This listing covers the 3.5 kW row (✓).
Key Features & Technology
4-Way Independent Airflow — True 360° Distribution
The Cassette 620 features 4-way airflow with each direction independently controllable. Unlike standard 4-way cassettes where all louvres move together, the 4 discharge sections can each be set to a different angle, closed off entirely, or swung in auto mode — allowing the airflow pattern to be tuned precisely to the shape and occupancy of the room. This eliminates dead spots in corners and prevents direct airflow onto desks or seated occupants.
4-way independentPer-direction controlNo dead spots
28 dB(A) Whisper-Quiet Operation — Quietest in the Cassette Class
The Cassette 620 achieves a minimum sound pressure of just 28 dB(A) — quieter than a library and among the lowest noise levels available in any ceiling cassette. Even on high speed, sound pressure reaches only 36 dB(A). A dedicated Silence mode drops the unit to its lowest fan speed for overnight use, meetings or other noise-sensitive situations.
The indoor unit body measures 570 × 570 × 260mm, mounting above the ceiling line in the ceiling void. The 620 × 620 × 60mm panel (PB-620KB) sits flush with the ceiling surface — significantly smaller than the 840 × 840mm panels of larger commercial cassettes. This compact footprint makes the Cassette 620 the right choice for lower ceiling voids, smaller rooms and spaces where a large cassette panel would look oversized. A black panel option is also available while stocks last — suited to dark or industrial-aesthetic ceilings.
The Cassette 620 chassis includes a fresh air inlet knockout, predisposed to accept a fresh air duct connection. When ducted to an external air source, this introduces a controlled percentage of outdoor fresh air directly into the conditioned airstream — maintaining CO₂ levels and indoor air quality (IAQ) in offices, meeting rooms and retail spaces with regular occupancy. An on/off card is supplied to enable or disable fresh air circulation without accessing the unit.
Fresh air inletOn/Off card included
UVC Sterilisation — Evaporator Sanitisation
Built-in UVC sterilisation uses ultraviolet-C light to sanitise the evaporator coil and internal surfaces, eliminating bacteria, mould spores and airborne pathogens. This runs automatically and requires no manual intervention — particularly relevant in shared commercial spaces such as offices, consulting rooms and retail environments with high footfall.
Rated SEER 6.1 (A++) in cooling and SCOP 3.8 (A) in heating. Nominal cooling output is 3.5 kW (range 0.9–4.5 kW) and nominal heating is 4.0 kW. Annual energy consumption is approximately 222 kWh/a cooling and 1427 kWh/a heating. The rotary inverter compressor modulates output continuously — no on/off cycling, quieter operation and faster response to load changes.
SEER 6.1 A++SCOP 3.8 ARotary inverter
Integrated hOn Wi-Fi — No Dongle Required
hOn Wi-Fi is built into the indoor unit. Download the hOn app (iOS, Android or Huawei AppGallery), connect to your network, and control the unit remotely from anywhere. Google Assistant and Amazon Alexa voice commands are supported. The app allows scheduling, mode selection, fan speed, louvre direction and energy monitoring.
Uses R32 refrigerant (GWP 675) — approximately one third the climate impact of R410A. Factory refrigerant charge is 0.78 kg (0.53 TCO₂eq). The smaller charge weight reduces the total CO₂-equivalent impact of the installation and simplifies F-Gas record-keeping.
4-way independent (each direction individually controllable)
Fresh Air
Inlet knockout predisposed + On/Off card
Sterilisation
UVC (built-in)
Wi-Fi
hOn — integrated (no dongle)
Panel Colour Options
White (standard) / Black (while stocks last)
ℹ Installation Note: Must be installed by a qualified F-Gas certified engineer in accordance with BS 7671 and manufacturer guidelines. Pipe lengths and refrigerant charges must be verified and adjusted on site. Interconnection cable and power cable sizing must comply with current wiring regulations.
Frequently Asked Questions
What size room is the Cassette 620 3.5 kW suited to?
At 3.5 kW nominal cooling output, this unit is suited to rooms of approximately 25–40 m² with standard 2.4–3.0m ceiling heights — small offices, meeting rooms, retail areas and larger domestic spaces. For spaces with high solar gain, poor insulation or many occupants, a heat gain calculation by a qualified engineer is recommended before selecting capacity.
What is the difference between 4-way independent and standard 4-way airflow?
A standard 4-way cassette moves all four louvre sections together — you can point them all in/out or sweep them, but each direction behaves identically. The Cassette 620's 4-way independent system controls each of the four discharge sections separately — so one side can blow horizontally, another can be closed, and the other two can sweep in auto mode simultaneously. This allows precise tailoring of the airflow pattern to the room's layout and occupancy.
What does the on/off card do?
The on/off card (included with the unit) is a simple enable/disable switch for the fresh air inlet function. When the fresh air duct is connected and the card is set to 'on', the unit draws in a controlled amount of outdoor fresh air into the conditioned airstream. When set to 'off', the unit recirculates indoor air only — useful when outdoor air quality is poor (e.g. during high pollen or pollution events).
Is a black panel available?
Yes — a black panel option (PB-620KB in black) is available while stocks last. This suits dark or industrial-aesthetic ceilings, restaurant settings and contemporary interiors where a white panel would look out of place. Contact us to check current availability.
Does it need F-Gas certification to install?
Yes — all refrigerant-containing systems must be installed by an F-Gas certified engineer registered with REFCOM, QUIDOS or VERITAS. Proof of F-Gas certification is required at the point of purchase.
Related Products
Haier Cassette 620 2.5 kW Kit
Same panel and body — different output
Haier 7 kW Round Flow Cassette Kit
360° 8-way commercial cassette for larger spaces
Haier Revive Plus 3.5 kW Wall-Mount
Wall-mounted monosplit alternative
BTU & WATT Calculator
Room Dimensions
Room Type
Living Room
Bedroom
Kitchen
Bathroom
Conservatory
Hallway
Glazing Type
Single Glazed
Double Glazed
Triple Glazed
External Walls
0 Wall
1 Wall
2 Walls
3 Walls
4 Walls
Insulation Level
Poor
Average
Good (New Build)
Required Heating
0
Watts
0
BTUs
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