Aircon Installation Singapore: System 2, 3 and 4 Sizing, Costs and the Complete Checklist

Aircon installation is the decision that determines how your home cools for the next ten years. Get the sizing, system count and pipe routing right and the system runs quietly, cheaply and reliably. Get it wrong and no amount of aircon servicing will make the flat comfortable. This guide explains how System 2, System 3 and System 4 setups work in Singapore, how to size units for HDB and condo rooms, what happens on installation day, and the questions to ask before you commit.

What "System 2, 3 and 4" actually means

In Singapore, a "System X" aircon means one outdoor condenser connected to X indoor fan coil units. A System 3 is one condenser serving three rooms. The number does not describe capacity on its own - a System 3 can be undersized or oversized depending on the BTU rating of each fan coil and the condenser matched to them.

• System 2 - typical for a 2-room or 3-room flat, or a condo with a master bedroom plus living room.
• System 3 - the most common choice for a 4-room HDB flat: two bedrooms plus the living room.
• System 4 - 5-room flats, executive flats and larger condos with three bedrooms plus living.
• Multi-split and above - landed homes, shophouses and commercial spaces, usually with more than one condenser.

One outdoor unit serving more rooms saves ledge space but shares capacity. If every fan coil runs simultaneously on a hot afternoon, an under-specified condenser will struggle. This is where sizing matters more than the headline system number.

Sizing: how many BTUs does each room need?

BTU/hr is the cooling capacity rating. As a practical Singapore guideline for typical ceiling heights:

Room	Approx. size	Typical capacity
HDB common bedroom	7-10 sqm	9,000 BTU
HDB master bedroom	11-14 sqm	9,000-12,000 BTU
Condo master with attached bath	14-18 sqm	12,000 BTU
HDB living room	18-25 sqm	18,000-24,000 BTU
Open-plan living and dining	25-35 sqm	24,000 BTU or two fan coils

Adjust upward for west-facing rooms with long afternoon sun, top-floor units, rooms with large glass windows, and spaces that regularly hold several people. Adjust downward only for shaded, north-facing, single-occupancy rooms.

Oversizing is not a safe default. An oversized aircon reaches setpoint quickly, shuts off, and never runs long enough to dehumidify, leaving the room cold but clammy - and short cycling wears the compressor. Undersizing means the unit runs continuously and still cannot hold temperature on hot days. Correct sizing is the single biggest lever on comfort and running cost.

Inverter versus non-inverter

Inverter systems vary compressor speed to match the load, holding temperature steadily and drawing far less power once the room is cool. Non-inverter systems run flat out then stop, producing temperature swings and higher long-run consumption. For Singapore households that run the aircon nightly, an inverter system nearly always pays back the higher purchase price. Non-inverter still makes sense for very light or occasional use, such as a guest room used a few nights a month.

Also check the NEA energy label ticks. A 5-tick inverter system will noticeably outperform a 2-tick unit on the bill over a decade of nightly use.

Choosing a brand

Every major brand sells reliable equipment in Singapore; the practical differences are parts availability, service network familiarity, noise levels and price. Uncle 7 Aircon installs and services all mainstream brands and will tell you plainly which models we see fewer problems with in the field.

What good aircon installation looks like

Installation quality matters more than brand. These are the details that separate a system that runs trouble-free for a decade from one that leaks, hisses and underperforms from year one.

1. Correct pipe sizing and length. Long refrigerant runs need charge adjustment; skipping this leaves the system permanently undercharged.
2. Proper flaring and torque. Most refrigerant leaks in new installations start at a badly flared joint.
3. Full vacuum before charging. Air and moisture left in the lines cause acid formation and compressor wear. Ask whether a vacuum pump will be used and for how long.
4. Continuous insulation. Both copper lines insulated end to end, with sealed sleeve penetrations - otherwise you get sweating pipes and dripping walls.
5. Drainage with a proper fall. Continuous downward slope, supported at intervals, with no sagging traps. This one detail prevents most future aircon water leaking calls.
6. Condenser placement. Adequate clearance for airflow, secure bracket, no boxing-in behind planters or storage.
7. Electrical work. Correctly rated isolator and cabling, tidy terminations, no piggybacking on an overloaded circuit.
8. Commissioning. Temperature split measured, drainage tested with water, every fan coil run-tested, and the remote paired and demonstrated.

Installation day: what to expect

A System 3 installation in an HDB flat typically takes most of a working day. The team protects floors and furniture, marks bracket positions, drills wall penetrations, runs copper and drain lines through trunking, mounts fan coils and the condenser, pressure-tests, vacuums, charges, and commissions. Expect drilling noise, some dust despite protection, and a request to keep the ledge and work areas clear. Uncle 7 Aircon starts installations from 9am; there is no after-hours installation.

Before the team arrives: clear furniture from the walls where fan coils will mount, clear the service ledge completely, decide trunking colour and routing, and confirm with your building management if approval is needed for ledge work in a condo.

Replacing an old system

When a system passes ten years and needs a compressor or has repeated refrigerant leaks, aircon replacement usually beats another repair. Replacement also lets you correct legacy problems: undersized bedroom units, an awkward condenser location, sagging drain runs, or piping that has been patched too many times. Old refrigerant types are another factor - systems on discontinued refrigerants become progressively more expensive to service.

Aircon dismantling is part of the job: safe recovery from the old system, removal of the old condenser and fan coils, and making good the mounting points before the new units go up.

Uncle 7 Aircon price list (Singapore, 2026)

Aircon service	Price
On-site diagnostic inspection	$40 flat
General aircon servicing (1 unit)	$40
General aircon servicing (2 units)	$100
General aircon servicing (3-9 units)	$18 per unit
General aircon servicing (10+ units)	$10 per unit
Aircon chemical wash (1 unit)	$60
Aircon chemical wash (2 units)	$80
Aircon chemical wash (3 units)	$90
Aircon chemical wash (4 or more units)	$28 per unit
Aircon chemical overhaul	$100 per unit

All aircon servicing prices above are flat rates confirmed on WhatsApp before the technician starts. Uncle 7 Aircon is a one-time aircon servicing specialist in Singapore: no contracts, no packages you cannot cancel, and no warranty upsell. You pay for the aircon service in front of you.

Installation is quoted per job, because pipe length, trunking, bracket work, drilling and disposal all vary by property. WhatsApp Uncle 7 Aircon with photos of your ledge and rooms and we will give you a clear figure. See our aircon installation service and aircon installation pricing pages for details.

After installation: the first year matters most

New systems are not maintenance-free. Renovation dust, packaging fibres and settling debris load the coil quickly in the first months. Book the first general aircon servicing at three months, then keep to a quarterly rhythm. Run fan-only for ten minutes before switching off at night, rinse the filters every few weeks, and keep the condenser clear. A new system treated this way rarely needs anything beyond routine aircon servicing for years.

Aircon installation notes by brand

Every aircon brand ages differently in Singapore's humidity, so aircon servicing is never one-size-fits-all. Here is what the Uncle 7 Aircon team watches for brand by brand.

Daikin aircon servicing

Daikin aircon servicing in Singapore usually involves inverter System 3 and System 4 sets that dominate newer HDB and condo installs. During a Daikin aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Daikin aircon servicing for details.

Mitsubishi Electric aircon servicing

Mitsubishi Electric aircon servicing in Singapore usually involves quiet Starmex fan coils that show dirt build-up as a slow drop in airflow. During a Mitsubishi Electric aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Mitsubishi Electric aircon servicing for details.

Panasonic aircon servicing

Panasonic aircon servicing in Singapore usually involves nanoe-equipped units where a clogged blower wheel is the usual smell culprit. During a Panasonic aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Panasonic aircon servicing for details.

LG aircon servicing

LG aircon servicing in Singapore usually involves ArtCool and Dualcool units with sensitive PCBs that dislike damp. During a LG aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See LG aircon servicing for details.

Midea aircon servicing

Midea aircon servicing in Singapore usually involves budget-friendly System 2 to System 4 sets popular in resale flats. During a Midea aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Midea aircon servicing for details.

Hitachi aircon servicing

Hitachi aircon servicing in Singapore usually involves older wall-mounted units that often need a chemical overhaul rather than a wash. During a Hitachi aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Hitachi aircon servicing for details.

Samsung aircon servicing

Samsung aircon servicing in Singapore usually involves Wind-Free models where blocked micro-holes cut cooling long before the unit fails. During a Samsung aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Samsung aircon servicing for details.

Toshiba aircon servicing

Toshiba aircon servicing in Singapore usually involves units with drain pans that silt up quickly in high-humidity blocks. During a Toshiba aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Toshiba aircon servicing for details.

Fujitsu aircon servicing

Fujitsu aircon servicing in Singapore usually involves compact fan coils common in shophouse and office ceilings. During a Fujitsu aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Fujitsu aircon servicing for details.

Sharp aircon servicing

Sharp aircon servicing in Singapore usually involves plasmacluster units that still need a physical coil clean every year. During a Sharp aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Sharp aircon servicing for details.

Mitsubishi Heavy Industries aircon servicing

Mitsubishi Heavy Industries aircon servicing in Singapore usually involves heavier condensers that need outdoor coil washing in dusty estates. During a Mitsubishi Heavy Industries aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See Mitsubishi Heavy Industries aircon servicing for details.

York aircon servicing

York aircon servicing in Singapore usually involves commercial-leaning systems found in shops, clinics and small offices. During a York aircon service we check the fan coil bearing noise, blower wheel loading, drain pan slope, filter condition and refrigerant behaviour, then advise whether a general aircon service, an aircon chemical wash or a full aircon chemical overhaul is the honest recommendation. See York aircon servicing for details.

Aircon installation and servicing across Singapore

Uncle 7 Aircon provides aircon servicing islandwide in Singapore. Aircon servicing needs differ by estate because building age, ledge exposure and drain runs all change how fast a fan coil gets dirty.

Aircon servicing in Ang Mo Kio

Aircon servicing in Ang Mo Kio is shaped by mature HDB blocks where 20-year-old piping means slower drainage. Uncle 7 Aircon covers Ang Mo Kio daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Ang Mo Kio on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Bedok

Aircon servicing in Bedok is shaped by coastal humidity that speeds up coil corrosion. Uncle 7 Aircon covers Bedok daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Bedok on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Bishan

Aircon servicing in Bishan is shaped by a mix of HDB and condo units with heavy evening usage. Uncle 7 Aircon covers Bishan daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Bishan on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Bukit Batok

Aircon servicing in Bukit Batok is shaped by west-side flats with dusty ledges that clog condensers. Uncle 7 Aircon covers Bukit Batok daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Bukit Batok on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Bukit Timah

Aircon servicing in Bukit Timah is shaped by landed homes running System 4 and multi-split setups. Uncle 7 Aircon covers Bukit Timah daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Bukit Timah on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Clementi

Aircon servicing in Clementi is shaped by student and family flats where aircons run almost non-stop. Uncle 7 Aircon covers Clementi daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Clementi on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Hougang

Aircon servicing in Hougang is shaped by older executive flats with long drain runs. Uncle 7 Aircon covers Hougang daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Hougang on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Jurong West

Aircon servicing in Jurong West is shaped by large estates with plenty of 10-year-old inverter sets. Uncle 7 Aircon covers Jurong West daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Jurong West on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Punggol

Aircon servicing in Punggol is shaped by newer BTOs where first servicing is often overdue. Uncle 7 Aircon covers Punggol daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Punggol on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Sengkang

Aircon servicing in Sengkang is shaped by young families running bedroom units through the night. Uncle 7 Aircon covers Sengkang daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Sengkang on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Tampines

Aircon servicing in Tampines is shaped by high-rise blocks with strong wind-driven dust on condensers. Uncle 7 Aircon covers Tampines daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Tampines on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Toa Payoh

Aircon servicing in Toa Payoh is shaped by central flats with tight ledge access. Uncle 7 Aircon covers Toa Payoh daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Toa Payoh on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Woodlands

Aircon servicing in Woodlands is shaped by north-side homes with heavy pollen and dust loading. Uncle 7 Aircon covers Woodlands daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Woodlands on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Yishun

Aircon servicing in Yishun is shaped by estates where trunking runs long and drains silt up. Uncle 7 Aircon covers Yishun daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Yishun on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Queenstown

Aircon servicing in Queenstown is shaped by older blocks needing overhauls more than washes. Uncle 7 Aircon covers Queenstown daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Queenstown on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Serangoon

Aircon servicing in Serangoon is shaped by condos with concealed ceiling units. Uncle 7 Aircon covers Serangoon daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Serangoon on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Pasir Ris

Aircon servicing in Pasir Ris is shaped by seaside flats where outdoor coils rust faster. Uncle 7 Aircon covers Pasir Ris daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Pasir Ris on WhatsApp and we confirm the flat price before the visit.

Aircon servicing in Choa Chu Kang

Aircon servicing in Choa Chu Kang is shaped by large family flats with multiple fan coils. Uncle 7 Aircon covers Choa Chu Kang daily from 9am for general aircon servicing, aircon chemical wash, aircon chemical overhaul, aircon repair, aircon gas top-up and aircon installation. Book aircon servicing in Choa Chu Kang on WhatsApp and we confirm the flat price before the visit.

Why choose Uncle 7 Aircon for aircon servicing in Singapore

Uncle 7 Aircon is a Singapore aircon servicing company built around one idea: honest aircon servicing at a flat price, done properly the first time. Homeowners across HDB flats, condominiums, landed homes, offices, retail shops and F&B outlets book Uncle 7 Aircon because the aircon servicing quote you hear on WhatsApp is the aircon servicing price you pay.

• 10+ years of aircon servicing experience across HDB, condo and commercial aircon systems in Singapore.
• Flat $40 on-site diagnostic inspection for every aircon repair job, quoted before any aircon repair work begins.
• Daily aircon servicing slots from 9am, islandwide. Uncle 7 Aircon does not run after-hours aircon servicing.
• Multi-brand aircon technicians trained on Daikin, Mitsubishi, Panasonic, LG, Midea, Hitachi, Samsung and more.
• 4.9 out of 5 stars from 100+ verified Carousell reviews for aircon servicing, chemical wash and aircon repair.
• One-time aircon servicing only - no maintenance contracts, no warranty gimmicks, no lock-in.

Aircon servicing FAQs (Singapore)

How long does aircon installation take in Singapore?

A System 2 typically takes half a day to a full day, a System 3 usually a full working day, and a System 4 can extend into a second day depending on trunking runs and access. Uncle 7 Aircon starts from 9am.

Is System 3 enough for a 4-room HDB flat?

For most 4-room flats, yes: 9,000 BTU for each of two bedrooms and 18,000 to 24,000 BTU for the living room. West-facing or top-floor flats may need the next capacity step up in the living area.

Should I choose inverter or non-inverter?

Choose inverter if the aircon runs most nights - the lower running cost outweighs the higher purchase price over a few years. Non-inverter can still make sense for very occasional use.

Can I reuse my existing copper piping?

Sometimes, if the pipe size matches the new system, the runs are in good condition and they can be properly flushed or purged. Old, undersized or contaminated piping should be replaced, and a technician should assess it rather than assume.

Do you handle aircon dismantling and disposal?

Yes. Uncle 7 Aircon dismantles the old fan coils and condenser, recovers refrigerant properly, and clears the equipment as part of a replacement job.

How much does aircon servicing cost in Singapore?

General aircon servicing with Uncle 7 Aircon starts at $40 for one unit, $100 for two units, $18 per unit for 3 to 9 units and $10 per unit for 10 or more units. An aircon chemical wash costs $60 for one unit, $80 for two, $90 for three and $28 per unit from four units. An aircon chemical overhaul is $100 per unit. Aircon repair starts with a flat $40 on-site diagnostic inspection.

How often should aircon servicing be done?

For most Singapore homes, general aircon servicing every three months keeps cooling strong and bills low. Households that run the aircon nightly, keep pets, or live near construction or the sea should service every two months. A chemical wash is typically needed once a year, and a chemical overhaul only when the coil and blower are heavily fouled.

What is included in general aircon servicing?

General aircon servicing includes filter cleaning, fan coil and blower wheel wiping, drain pan and drain pipe clearing, vacuuming of the condensate line, cooling temperature check, airflow check, and a visual inspection of the outdoor condenser. It takes about 15 minutes per unit.

How long does aircon servicing take?

General aircon servicing takes about 15 minutes per unit, an aircon chemical wash takes about 30 minutes per unit, and an aircon chemical overhaul takes about 60 minutes per unit. A three-unit chemical wash appointment usually finishes within 90 minutes.

Does Uncle 7 Aircon offer after-hours aircon servicing?

No. Uncle 7 Aircon starts aircon servicing appointments from 9am daily and does not offer after-hours service. WhatsApp us to reserve a morning or afternoon slot.

Is there a diagnostic fee for aircon repair?

Yes, a flat $40 on-site diagnostic inspection applies to aircon repair jobs. The technician tests the unit on site, explains the fault and quotes the aircon repair transparently before any work begins.

Do you provide aircon servicing for HDB, condo and commercial units?

Yes. Uncle 7 Aircon handles aircon servicing for HDB flats, private condominiums, landed homes, offices, retail shops, F&B outlets and clinics across Singapore.

Do you offer warranty or maintenance contracts?

No. Uncle 7 Aircon is a one-time aircon servicing specialist. There are no maintenance contracts and no warranties - you pay only for the aircon servicing job done on the day.

Which aircon brands do you service?

Uncle 7 Aircon services Daikin, Mitsubishi Electric, Mitsubishi Heavy Industries, Panasonic, LG, Midea, Hitachi, Samsung, Toshiba, Fujitsu, Sharp and York aircon systems, including System 2, System 3 and System 4 installations.

Do you cover my area for aircon servicing?

Uncle 7 Aircon provides aircon servicing islandwide in Singapore, from Jurong West and Bukit Batok in the west to Tampines, Bedok and Pasir Ris in the east, plus all central estates. Share your postal code on WhatsApp and we confirm the slot.

Contact Uncle 7 Aircon

Ready to book aircon servicing in Singapore? WhatsApp Uncle 7 Aircon at 9431 1589 with your postal code, aircon brand, number of units and the problem you are seeing. We reply with a flat aircon servicing price and the next available slot from 9am. You can also compare every service on our aircon servicing price list, browse all aircon services, or read more guides in the Knowledge Hub.