Solo 9S$1,180
System 1 · 5-tick inverter
A small bedroom or study under 13 m². The simplest upgrade from an old window unit.
9,000 BTU · 5 ticks · 21 dB(A) · about S$25 a month to run · 7-yr compressor
Bring the hot room down to 25°
Kelvin & Co. supplies, installs and services aircon across Singapore. Six questions, and the dial names the three systems that cool your rooms, priced installed.
Room now
31°
304 K, cooling to 25°C
- Calm System 35 ticks · 21 dB(A) · from S$3,680
- Quiet Night 125 ticks · 19 dB(A) · from S$1,580
- Halo Cassette 244 ticks · 31 dB(A) · from S$3,280
Not sure which system you need?
Browse all 18 systems with their BTU, energy ticks, noise and installed price, or tell us about your rooms and we will choose for you.
Which rooms are too hot?
Pick every room you want cooled. Each gets its own indoor unit, all on one outdoor unit.
When is it at its worst?
West-facing and top-floor rooms run hotter, so we size them up one step.
What kind of home is it?
This sets the size of each room and where the outdoor unit can go.
What is on the wall now?
This changes your price, not your shortlist.
What matters most to you?
We rank the systems that fit by this.
What is your budget, installed?
Including GST, standard piping and labour.
Your best 3
Question 1 of 618 systems to choose from
Every system, priced installed
Our price sheet: the 18 systems we fit, grouped by how many rooms they cool. Each line gives the BTU per indoor unit, NEA ticks, noise, running cost and the price with standard piping and 9% GST.
One room, one system
6 systems
Solo 12S$1,380
System 1 · 5-tick inverter
One room, done well. Right for a master bedroom or a study up to 18 m².
12,000 BTU · 5 ticks · 22 dB(A) · about S$32 a month to run · 7-yr compressor
Quiet Night 12S$1,580
System 1 · Ultra-quiet bedroom unit
19 dB(A) on night mode, quieter than a whisper. Matte graphite, display off while you sleep.
12,000 BTU · 5 ticks · 19 dB(A) · about S$32 a month to run · 7-yr compressor
Pure 12S$1,680
System 1 · 5-tick · purifying
The one-room Pure: PM2.5 filter and ioniser for the bedroom that needs it most.
12,000 BTU · 5 ticks · 22 dB(A) · about S$34 a month to run · 7-yr compressor
Solo 18S$1,880
System 1 · 4-tick inverter
One strong unit for an HDB or condo living and dining area up to 28 m².
18,000 BTU · 4 ticks · 30 dB(A) · about S$59 a month to run · 5-yr compressor
Solo 24S$2,380
System 1 · 4-tick inverter
For a large living room, a west-facing corner or a small shop.
24,000 BTU · 4 ticks · 33 dB(A) · about S$76 a month to run · 5-yr compressor
Two to five rooms, one outdoor unit
9 systems
Everyday System 2S$2,180
System 2 · 4-tick inverter
Two bedrooms, one outdoor unit, a fair price. Bedrooms only: fan coils go up to 12,000 BTU.
9,000 + 9,000 BTU · 4 ticks · 26 dB(A) · about S$63 a month to run · 5-yr compressor
Calm System 2S$2,780
System 2 · 5-tick inverter
Two rooms on one outdoor unit. Popular in 3-room flats, or for the bedrooms of a bigger home.
12,000 + 9,000 BTU · 5 ticks · 21 dB(A) · about S$57 a month to run · 7-yr compressor
Everyday System 3S$2,880
System 3 · 4-tick inverter
The sensible System 3: honest 4-tick efficiency at a price that suits rental flats and tight budgets.
12,000 + 9,000 + 9,000 BTU · 4 ticks · 26 dB(A) · about S$103 a month to run · 5-yr compressor
Calm System 3S$3,680
System 3 · 5-tick inverter
Our best-seller for 3- and 4-room flats: two bedrooms and the living room on one slim outdoor unit.
18,000 + 9,000 + 9,000 BTU · 5 ticks · 21 dB(A) · about S$97 a month to run · 7-yr compressor
Everyday System 4S$3,880
System 4 · 4-tick inverter
All four rooms of a 4-room flat for under S$4,000 installed.
18,000 + 9,000 + 9,000 + 9,000 BTU · 4 ticks · 27 dB(A) · about S$153 a month to run · 5-yr compressor
Quiet Night System 3S$4,080
System 3 · Ultra-quiet · 5-tick
Three bedrooms at 19 dB(A). Bedrooms and study only: its fan coils go up to 12,000 BTU.
12,000 + 9,000 + 9,000 BTU · 5 ticks · 19 dB(A) · about S$82 a month to run · 7-yr compressor
Pure System 3S$4,280
System 3 · 5-tick · purifying
A PM2.5 filter and ioniser in every fan coil. For allergies, haze season and light sleepers.
18,000 + 12,000 + 9,000 BTU · 5 ticks · 22 dB(A) · about S$106 a month to run · 7-yr compressor
Calm System 4S$4,980
System 4 · 5-tick inverter
Every room of a 4- or 5-room flat on one outdoor unit, at 5-tick efficiency.
18,000 + 12,000 + 9,000 + 9,000 BTU · 5 ticks · 21 dB(A) · about S$129 a month to run · 7-yr compressor
Calm System 5S$6,280
System 5 · 5-tick inverter
Five fan coils on one outdoor unit for 5-room flats, EAs and big condos with a study.
18,000 + 12,000 + 12,000 + 9,000 + 9,000 BTU · 5 ticks · 21 dB(A) · about S$161 a month to run · 7-yr compressor
Ceiling systems
3 systems
Halo Cassette 24S$3,280
System 1 · 4-way ceiling cassette
Even airflow from the ceiling for big landed living rooms and open offices. Needs a false ceiling.
24,000 BTU · 4 ticks · 31 dB(A) · about S$76 a month to run · 5-yr compressor
Slimline Ducted 3S$5,680
System 3 · Concealed ducted · 5-tick
Hidden in a slim bulkhead, with only a linear grille on show. For homes with a false ceiling.
18,000 + 9,000 + 9,000 BTU · 5 ticks · 24 dB(A) · about S$107 a month to run · 7-yr compressor
Workday Office DuoS$5,880
System 2 · Twin ceiling cassettes
Two ceiling cassettes on one outdoor unit: an open work area plus a meeting room, with office-hours timers.
24,000 + 18,000 BTU · 4 ticks · 30 dB(A) · about S$124 a month to run · 5-yr compressor
Running costs are estimates at about S$0.30/kWh, 8 hours a day per indoor unit; your bill depends on room size, sun and the temperature you set. House-range names are our own; the exact model is named in your written quote.
What does your old aircon cost to run?
Set your rooms and hours. We compare your aircon with a 5-tick inverter at about S$0.30/kWh, using typical 9,000 to 12,000 BTU bedroom units.
Six answers, one visit, one day
No sales visit before you have seen prices. The finder gives you a shortlist, the site check turns it into a fixed quote, and most System 3 and 4 jobs are fitted in a day.
Answer
Today, in two minutes. You leave with three systems and a price for your home, not a sales call.
Check
Within three days. We look at your aircon ledge, piping route, trunking and power points, and send a fixed, itemised quote the same day.
Install
About a week later. Floors covered, drill dust vacuumed, and the first servicing free at three months.
Servicing, washes and repairs
Every three months
Filters washed, coil and blower cleaned, drain flushed and gas pressure checked, with a WhatsApp reminder the week before.
From S$30 per indoor unit
When it smells or drips
A chemical wash for units that smell musty, drip or cool weakly: once a year, or sooner in haze season. A full overhaul for older units.
From S$80 per indoor unit
Leaks, codes, warm air
Water leaks, error codes, warm air and noisy fans. Diagnosis is S$60, waived if we do the repair. R32 and R410A gas top-ups.
Gas top-up from S$60
Old out, new in, one day
If your copper piping passes our pressure test, we reuse it and take about S$120 a room off the quote. Old units leave with us.
Old units removed free
October's jobs, by estate
Fitted and serviced by our own salaried crew.
Punggol
Calm System 4 in a BTO 4-room. Fitted in one day for S$4,980.
Tampines
Calm System 3 in a condo. Old piping reused: S$3,320.
Toa Payoh
Quiet Night System 3 in a 5-room. West bedroom sized up.
Bukit Timah
Halo Cassette 24 in a semi-D living room that faces west.
Tai Seng
Workday Office Duo for a design studio, fitted on a Sunday.
Woodlands
Solo 12 for a study. Site check Monday, fitted Wednesday.
Tampines condo, Calm System 3
18,000 + 9,000 + 9,000 BTU · fitted in one day · S$3,320 after the piping credit · bill down S$54 a month
“The finder put the Calm 3 on top and the site check agreed. Our old piping passed the test, so the quote came down before we asked.”
Joanne L., Tampines
Toa Payoh 5-room, Quiet Night System 3
19 dB(A) on night mode · west bedroom sized up · fitted on a Saturday
“Our daughter sleeps right under the unit and does not hear it. They sized the west bedroom up without us asking.”
Hafiz R., Toa Payoh
Kelvin Ong's crew, since 2009
Named after a temperature
Kelvin is the scale scientists use for temperature, and the name of our founder. 25°C is 298 K: where we leave every room we fit.
Our own people
Kelvin started in Woodlands with one van and a ladder. Today we are 26 people, with 18 salaried installers and technicians, trained in-house and insured. Siti Rahmah runs quotes, Marcus Lee leads servicing, Ravi Kumar takes landed and office jobs, and Kelvin still does site checks.
Questions before you call
Still unsure? WhatsApp us a photo of your aircon ledge and the room, and we will tell you what fits.
How many BTU do I need for an HDB bedroom?
Most HDB bedrooms of 10 to 13 m² need a 9,000 BTU indoor unit, and a master bedroom up to about 16 m² needs 12,000 BTU. A 4-room living and dining area usually takes 18,000 BTU. If the room faces west or sits on the top floor, go one size up. We confirm sizing at the free site check.
What temperature should I set my aircon to?
Set it to 25°C. That is the setting NEA suggests for Singapore homes, and it is where our finder's dial stops. Each degree lower makes the compressor work harder for little extra comfort. Use the fan and the sleep mode at night instead, and close the curtains on the west side in the afternoon.
Is a 5-tick inverter aircon worth the extra cost?
Usually yes, if you run the aircon most nights. Under NEA's energy label, a 5-tick system uses roughly 20% less power than a 4-tick one, so a System 3 saves about S$20 to S$25 a month at S$0.30/kWh. The price gap of about S$800 pays back in around three years, well inside a 7-year compressor warranty.
Where can the outdoor unit go in an HDB flat or condo?
In HDB flats the outdoor unit must sit on the designated aircon ledge, on proper brackets, with safe access for servicing. Condos follow the MCST's by-laws, which often fix the ledge, unit colour and pipe route, so we check them before quoting. Landed homes can use a wall, roof or yard position with good airflow.
How often should I service my aircon in Singapore?
Every three months for general servicing, because Singapore's heat, humidity and dust clog filters and drain pipes quickly. Add a chemical wash about once a year, or sooner if the unit smells musty, drips or cools weakly. Regular servicing keeps bills down, and most warranties ask for proof of it.
Can you reuse my old aircon piping?
Often, yes. On replacement jobs we flush and pressure-test the existing copper piping. If it holds pressure and the pipe sizes suit the new system, we reuse it and take about S$120 a room off the quote. If it fails the test, we replace it, and your quote shows that line clearly before we start.
Do your prices include GST and installation?
Yes. Every price on this site includes 9% GST, delivery and installation with standard copper piping, trunking, drain pipe and brackets, plus removal of packaging. Extras such as longer pipe runs, a new power point or false-ceiling work are listed separately in your written quote before any work begins.
Book a free site check
We reply within the hour in opening hours, check your ledge and piping route, and send a fixed, written quote the same day.
- Showroom
- Woodlands Loop, Singapore, by appointment
- Hours
- Mon to Fri 8:30 am to 6:30 pm, Sat 9 am to 5 pm