SAC4M-28UHS/I

Year-Round Comfort

Operating as a robust air-to-air heat pump, this unit provides reliable year-round climate control, certified for heating in outdoor temperatures down to -15°C and stable cooling up to +43°C. Its electronic expansion valves (EEVs) dynamically allocate the cooling or heating capacity to each of the four connected ports based on real-time room demands, maintaining temperatures in active zones with an accuracy of up to 0.5°C.

Technical Advantages & Features

• Energy Efficiency Class (A++ / A+): Equipped with advanced DC inverter control, the compressor scales its output precisely to match the thermal load of the active rooms, preventing unnecessary energy draw and keeping seasonal utility costs highly efficient.

• Twin-Rotary Inverter Compressor: Powered by a heavy-duty twin-rotary compressor with enhanced rotor balancing and dual-layer sound insulation, ensuring quiet operation and minimum vibration transmission to the building's exterior walls.

• Eco-Friendly R32 Refrigerant: Fully optimized for next-generation, ozone-safe R32 refrigerant, which increases thermal conductivity and heat transfer efficiency by 10% while using a lower charge volume.

• Smart On-Demand Defrosting: Utilizes an intelligent defrost cycle that only activates when frost buildup is detected on the outdoor coil, maintaining optimal heating performance during humid, sub-zero winter days.

Installation & Operation Insights

• From our engineering teams' experience: The SAC4M-28UHS/I is a powerful unit where up to four separate refrigerant lines (typically 1/4" liquid and 3/8" gas pipes) converge. Meticulous calculation of total piping lengths, elevation drops, and oil traps is critical to ensure equal refrigerant distribution.

• Given its physical size and operating pressure, we mount this unit on heavy-duty, reinforced steel brackets or floor-standing platforms using industrial-grade rubber vibration dampers to completely isolate compressor resonance from the building's living spaces.

Comparison with the Previous SAC3M-24UHS/I Model

While both units belong to SENSEI's versatile multi-split lineup, the SAC4M-28UHS/I offers distinct structural and capacity upgrades over the SAC3M-24UHS/I:

• Port Capacity: The SAC4M-28UHS/I features 4 ports, allowing you to connect up to 4 indoor units, whereas the SAC3M-24UHS/I is limited to a maximum of 3 ports.

• Performance Boost: Delivering 28,000 BTU (8.2 kW) compared to the 24,000 BTU (7.1 kW) of the SAC3M model, this unit handles larger total areas (up to 90 m² vs 75 m²) and provides greater thermal reserve when multiple indoor units operate simultaneously.

• System Flexibility: If you have a 3-zone layout but plan to expand or add a 4th room (such as a glazed balcony or a guest room) in the future, choosing the SAC4M-28UHS/I provides the necessary physical port and capacity headroom that the SAC3M-24UHS/I cannot support.

Best Suited For:

• Owners of 3- to 4-room apartments and townhouses with strict architectural rules prohibiting multiple outdoor brackets on the building's facade.

• Commercial layouts, dental clinics, or open offices that require highly reliable, multi-zone heating and cooling with minimal outdoor equipment clutter.

Might Not Be Suited For:

• If you do not plan to connect more than 3 indoor units and your total area is under 70 m², investing in this 4-port model is redundant; the SAC3M-24UHS/I will be a more cost-effective and compact choice.