When you move into a 5-room HDB flat in Singapore, one of the most important decisions is choosing to install aircon between a System 3 or System 4 aircon setup. With multiple bedrooms, a living and dining space, and sometimes even a suggested study, the choice directly affects your comfort, energy efficiency, and monthly bills. This guide explores the difference between these two systems in the context of a standard 5-room layout, helping you decide which is right for your household.
Understanding System 3 and System 4 Aircon
In simple terms, a System 3 aircon connects three indoor units to a single outdoor compressor, while a System 4 supports four indoor units. Since HDB flats only provide one small aircon ledge, multi-split systems are the standard choice in Singapore.
If you’re not familiar with the basics of multi-split setups, you can check out our article on System 3 Aircon Meaning for a detailed explanation.
How Install Aircon System 3 Setup Fits into a 5-Room HDB
In many 5-room homes, a System 3 is installed in the living/dining room, the master bedroom, and one additional bedroom. This setup covers the most frequently used spaces at a lower installation cost.
However, the trade-off is that one bedroom or study remains without dedicated cooling. If Bedroom 3 is used as a guest room or the study is converted into a home office, you might find yourself relying on a fan or portable unit.
When to Choose System 4
A System 4 aircon gives you the flexibility to cool all key spaces: the living room, master bedroom, Bedroom 2, and Bedroom 3 (or the study). This option is more suitable for larger families where every room is actively used, or for households with multiple people working from home.
While the upfront cost is higher than a System 3, the benefit is comfort and convenience in every room. Our Install Aircon Guide explains why planning for future usage is just as important as the initial budget.
Energy Efficiency and R32 Gas
Both System 3 and 4 models now run on R32 refrigerant, which is more eco-friendly and energy-efficient compared to older gases. With a 5-room flat, the outdoor compressor will naturally take on more load if all units are running, but choosing a properly sized system ensures smooth operation. Learn more about the benefits of R32 Aircon Gas in Singapore and why it’s the future standard for air-conditioning.
Energy Efficiency and R32 Gas
Both System 3 and 4 models now run on R32 refrigerant, which is more eco-friendly and energy-efficient compared to older gases. With a 5-room flat, the outdoor compressor will naturally take on more load if all units are running, but choosing a properly sized system ensures smooth operation. Learn more about the benefits of R32 Aircon Gas in Singapore and why it’s the future standard for air-conditioning.
Practical Scenarios to Consider Before Install Aircon
If you’re a smaller family of three, a System 3 may be enough since not all bedrooms will be occupied at the same time. But if you’re planning for a larger household or foresee long-term use of the study as a work-from-home space, a System 4 will pay off in convenience.
It’s also worth factoring in your BTU requirements. The living room in a 5-room flat typically needs a higher-capacity unit (12,000–18,000 BTU), while bedrooms can operate comfortably with smaller units (9,000 BTU). You can explore our BTU guide for Mitsubishi Starmex to calculate the right size for each room.
Final Recommendation
For most 5-room HDB households, the choice comes down to lifestyle. If your priority is budget and essential cooling, a System 3 will work well. But if you value comfort and flexibility across all rooms, investing in a System 4 is a smarter long-term solution.
When making this decision, always consult a professional installer to match your aircon setup with your family’s needs and HDB layout. For more guidance, you can also explore our insights on aircon installation in Singapore.
