Singapore is a hot and humid country which needs air conditioner all around the year. People living in HDB flats in Singapore need to install or replace aircon units often. Installing a new aircon is often a difficult job because of the regulations and lack of information. If you’re thinking of installing aircon in HDB, this guide is going to be a great help. Let’s discover the costs, options available, steps involved and frequently asked questions on aircon installation in HDB flats in Singapore.
Which Aircon To Choose For HDB Flats?
There are different available aircon options in Singapore. The requirement is not the same for everyone. For example, the requirement for a small and large flat will be different because of the number of room to be cooled is different.
1. System 1 (1 indoor unit + 1 outdoor unit)
Best for: One-room cooling, such as a bedroom or study room.
System 1 is suitable if you only need to cool a single room. It’s the most affordable in terms of upfront cost and power consumption. It is easy to maintain and does not need complex piping. This option is good for small households or when only one person uses the aircon regularly.
2. System 2 (2 indoor units + 1 outdoor unit)
Best for: Two-room flats or if you want aircon in both the bedroom and living room.
This setup cools two rooms using one outdoor compressor. It saves space and electricity compared to two separate System 1 units. It also reduces installation cost since the trunking and electrical setup can be shared. It’s a good choice for couples or small families who use the living room and one bedroom frequently.
3. System 3 (3 indoor units + 1 outdoor unit)
Best for: Three-room flats or those who want cooling in the living room and two bedrooms.
System 3 is a popular choice for standard HDB flats. It balances cooling comfort and energy efficiency. With one outdoor unit powering three indoor units, this system keeps your flat cool without high energy bills. It’s ideal for families with kids who need cooling in multiple rooms throughout the day or night.
4. System 4 (4 indoor units + 1 outdoor unit)
Best for: Four-room flats or when all rooms need cooling.
System four aircon cools four areas using just one outdoor unit, making it space-saving and practical for larger flats. It allows you to enjoy consistent cooling in all bedrooms and the living room. While it’s more costly upfront, it reduces the need to install multiple compressors and is more efficient in long-term use.
5. Inverter vs Non-Inverter Systems
Best for: Energy-saving and long-term use (Inverter); Budget short-term use (Non-Inverter)
Inverter aircon adjusts power based on room temperature, using less energy and offering quieter operation. It’s better for daily or long hours of use. Non-inverter models are cheaper but use more power and may wear out faster. For most HDB users, inverter systems are the better value over time despite higher initial costs.
Aircon installation cost in HDB
Below is the estimated cost of aircon installation in HDB Singapore:
| Item | System 1 | System 2 | System 3 | System 4 | System 5 |
| Unit cost | SG$600–1,000 | SG$1,200–1,600 | SG$1,800–2,400 | SG$2,800–3,800 | SG$4,000–5,000 |
| Labour | SG$200–300 | SG$300–400 | SG$400–500 | SG$600–800 | SG$800–1,000 |
| Piping & drainage | SG$150–250 | SG$250–350 | SG$300–450 | SG$450–600 | SG$500–700 |
| Electrical & circuit breaker | SG$100–150 | SG$150–200 | SG$200–250 | SG$250–300 | SG$300–400 |
| Total Cost | SG$1,050–1,700 | SG$1,900–2,550 | SG$2,700–3,600 | SG$4,100–5,500 | SG$5,600–7,100 |
HDB Aircon Installation Step-by-Step Process
Now, let’s see what you need to do for aircon installation in HDB in below step by step process:
Step 1: Choose the Right Aircon
Start by deciding how many rooms you want to cool. Look at the size of each room and your daily usage. A System 1 is good for one room, while System 3 or 4 suits larger flats. Check the energy rating tick marks as well. A more efficient unit can lower your electricity bills over time. Always choose an aircon from trusted brand with a good warranty.
Step 2: Check for Aircon Ledge
Most HDB flats have an aircon ledge for outdoor units. Make sure your flat has one. If it doesn’t, you will need to request aircon approval from HDB to install the outdoor unit.
Step 3: Hire a Licensed Installer
HDB has an aircon installation regulation requirement that all aircon installations be done by licensed installers. These professionals follow safety rules and know how to handle the wiring, trunking, and pipework properly.
Step 4: Prepare for Installation
Before installation day, make some space around windows and the areas where the aircon will be placed. Move furniture or cover it with plastic sheets. Inform your installer if you have any special wall types, like wood or glass panels. Also, check if your flat has existing trunking from an old system.
Step 5: Installation
The installer will mount the indoor units on your chosen walls and the outdoor unit on the aircon ledge. They will install trunking to hide the gas pipes and electrical cables. Drain pipes will also be added to prevent water leakage. After all units are in place, they will connect the system, vacuum the pipes, and test it to ensure it is running properly.
Step 6: Final Check
Once everything is installed, you should test each indoor unit to make sure it’s cooling. Ask the installer to show you how to use the remote controls and adjust the settings. Also ask about basic maintenance like filter cleaning. Keep the warranty card and receipt in a safe place for future servicing or repair.
HDB Aircon Installation Regulations and Permits
Installing an aircon in an HDB flat must follow certain rules. These are in place to keep everyone safe and to protect the building.
1. Use a Registered Installer
You must hire a BCA-trained installer who is listed in the HDB Directory of Renovation Contractors. This ensures the person knows how to install aircon safely in HDB flats.
2. Aircon Ledge Use
The outdoor compressor unit must be placed on the aircon ledge provided by HDB. You are not allowed to install the outdoor unit at the window or on walls facing public areas.
3. No Overloading
Make sure the power supply can handle the aircon system. Large systems may require a higher electrical load, and you may need to apply for an HDB permit to upgrade your electricity capacity.
4. Proper Trunking
Trunking (pipes and cables) must be installed neatly and securely. It should not block escape routes or windows. Pipes must be well-sealed to prevent water leakage that can damage walls or ceilings.
5. Window Unit Restrictions
Window-type air conditioners are not allowed unless they were installed before newer rules came into effect.
6. Approval for Non-Standard Installation
If your flat does not have an aircon ledge, or if you want to install aircon in a way that’s not common (e.g., running pipes across rooms), you must apply for special approval from HDB.
7. Follow NEA Energy Labelling
Only units with proper energy labels ( issued by NEA) are allowed to be sold and installed in Singapore.
FAQ
What type of aircon is allowed in HDB flats?
HDB allows split-type air conditioners with one outdoor unit. You must use a licensed installer and follow HDB’s installation guidelines.
Do I need permission from HDB to install an aircon?
If your flat has a proper aircon ledge and the installation follows HDB rules, no extra approval is needed.
Can I install the aircon myself?
No. HDB requires that all aircon installations be done by a BCA-trained installer registered under the Directory of Renovation Contractors.
How long does aircon installation take?
Most installations take about 4 to 6 hours. If you are installing a full system (System 3 or 4), or replacing an old unit with new trunking, it may take longer.
What is the best time to install aircon?
It’s best to install during renovation or before moving in. This makes it easier to run trunking without needing to move furniture or redo walls.
