If you are cooling five rooms in your HDB, condo, or landed house in Singapore, you may be thinking about installing a System 5 or going for a System 3 + 2 setup. Both can cool five rooms, but they work in different ways. How do you decide which one is better for your needs? Let’s break it down in a simple way.
What Is a System 5 Aircon?
A System 5 aircon means one outdoor unit is connected to five indoor units. With this system, you can cool five rooms using just one compressor.
Benefits of System 5:
- Takes up less outdoor space
- Only one compressor to maintain
- Neater look
Limitations of System 5:
- Compressor load is high
- If the compressor fails, all five indoor units are affected
- Limited BTU per room (not suitable for very large rooms)
- Higher installation cost
What Is a System 3 + 2 Aircon?
A System 3 + 2 setup means two outdoor units. One outdoor unit runs three indoor units (System 3), and the other runs two (System 2). Together, they cool five rooms.
Benefits of System 3 + 2:
- Two compressors mean less stress on each
- More BTU flexibility — better for bigger rooms
- If one system fails, the other still works
- Lower installation cost
Limitations of System 3 + 2:
- Needs more outdoor space
- More wiring and piping
System 5 or System 3+2: Which One Is Better for You?
Both models can be great options for different situations:
Choose System 5 if:
- You have limited outdoor space (like in many HDBs)
- All five rooms are similar in size and usage
- You prefer a simple setup
Choose System 3 + 2 if:
- You have space for two compressors (e.g., in a larger condo or landed home)
- You need more BTU in some rooms (like a big master bedroom or study)
- You want a backup in case one system breaks down
- You prefer to split power use
- You want a lower installation cost
Factors to Consider
Below are a few factors that you should consider while choosing between a system 5 or a system 2+3 combination:
Number of Rooms
Count how many rooms you want to cool. System 5 connects up to 5 indoor units using one outdoor unit. System 3 + 2 uses two outdoor units to power five indoor units. Both units are good for cooling 5 rooms simultaneously.
Outdoor Space
If your home has limited outdoor space, System 5 may be more suitable as it requires only one outdoor unit.
Power Distribution
System 3 + 2 offers better flexibility. You can run only one system when needed, which can help save electricity.
Installation Cost
System 3 + 2 usually costs less to install. But the price difference is not that much.
Maintenance
With System 3 + 2, a problem in one system does not affect the other. In System 5, if the main unit fails, all five indoor units may stop working. Consider this while making your decision.
Cooling Performance
Check if the System 5 unit has enough BTU power to handle all rooms. If too many indoor units run at once, cooling may be weaker. System 3 + 2 may give more stable performance when all rooms are used.
Popular Brands in Singapore for System 5 or System (3+2)
Below are the aircon brands in Singapore to consider for split aircon systems:
- Daikin
- Mitsubishi Electric
- Panasonic
- LG
- Midea
Most of these brands offer both System 5 and System 3 + 2 setups. Always check the total BTU and NEA tick rating before choosing.
System 5 and System (3+2) Price Comparison
Cost of System 5
Estimated cost: SG$5,600–SG$7,100 (with installation)
One outdoor unit connected to five indoor units
Higher upfront cost
Cost of System 3 + System 2
System 3: SG$2,700–SG$3,600
System 2: SG$1,900–SG$2,550
Total combined: S$4,600 – S$6,150 (with installation)
So, is System 5 more expensive?
Yes — in most cases, a System 5 aircon is slightly more expensive than a 3+2 setup, especially if you’re choosing premium brands or larger BTU combinations. But the difference is usually not drastic.
FAQ
What is BTU and why does it matter?
BTU stands for British Thermal Unit. It shows how powerful the aircon is. Bigger rooms need more BTUs. If your room is large and the BTU is too low, cooling will be slow and less effective.
Can I install a System 5 in an HDB flat?
Yes, but only if your electrical load and outdoor ledge space allow it. Always check with HDB guidelines and your contractor.
Is System 3 + 2 more reliable?
It can be. If one compressor breaks, the other still works. This adds some safety if you use aircon daily.
Which one uses more electricity?
It depends on how often and how many rooms you use. If all five rooms are used daily, System 5 may use less power. If some rooms are rarely used, System 3 + 2 may be better.
Do I need regular servicing?
Yes. In Singapore’s hot and humid weather, filters get dirty fast. Clean your filters every 2-4 weeks and do full servicing every 6 months.
