The best temperature to set your air conditioner in Thailand

Every Bangkok household has had the argument. One person wants the air conditioner at 22°C because the room feels sticky; another points at the electricity bill and wants 27°C. Both are reacting to something real: a lower set-point feels cooler but costs more to run, and a higher one saves money only if the room is still comfortable enough to sleep and work in.

This guide gives you a number to start from, shows who recommends it, and explains the reasoning so you can tune it for your own room. It also covers what most set-point advice leaves out: humidity, fans, dry mode, babies and older relatives, and why a dirty unit makes every setting less effective. Where we give a figure, it comes from a source linked in the text; where we are offering practical advice rather than evidence, we say so.

The short answer

Start at 26°C, add a fan, and raise the set-point one degree at a time until the room is just comfortable. That follows what Thailand's energy agencies recommend: 26–27°C, with an electric fan to circulate the cool air.

Three qualifiers matter. There is no single perfect number, because comfort depends on humidity, air movement, clothing, how many people are in the room and how hot the walls are. The savings from a higher set-point are real but are estimates, and the agencies phrase them as "up to". And the number on the remote is a target for the unit, not a guarantee of how the room feels: a unit with a clogged filter or a fouled coil can show 25°C on the display and still deliver a weak, warm room.

What the Thai government recommends, and who says so

The clearest official statement we can verify is from 2023. On 25 April the Ministry of Energy, the Department of Alternative Energy Development and Efficiency (DEDE) and the Electricity Generating Authority of Thailand (EGAT) launched a hot-season campaign called "Save Energy for ALL". According to EGAT's release, DEDE's director general summarised the advice as "adjust, clean, set, and reduce": dress lightly, clean air filters every one to two months with a major clean every six months, set the air conditioner to 26–27°C and use electric fans to circulate the cool air, and cut the running time by one hour a day.

The same release is the source of the saving estimates quoted most often in Thai media. It says cleaning an air conditioner can save up to 10% of the electricity cost (about 210 baht a month), and that raising the temperature by 1°C can save up to 4.5% (about 100 baht a month). Both together, it says, can cut the cost by at least 300 baht a month per unit. These are DEDE's stated figures for a typical unit, expressed as ceilings, so read them as a best case for an ordinary household, not a promise for yours.

The number returned to the news in March 2026. The Nation reported that on 10 March the Cabinet ordered government offices to set their air conditioning at 26°C as part of measures to cut electricity use. That order was addressed to government offices, not households, and we have not verified whether it is still in force, so treat it as evidence that 26°C remains the official benchmark rather than a rule for your home.

The World Health Organization gives similar advice for a different reason. In its heat and health fact sheet, WHO suggests that anyone using air conditioning in hot weather sets the thermostat to 27°C and turns on an electric fan, which it says makes the room feel 4°C cooler and can save up to 70% on the cooling bill. Treat that last figure as an upper bound that WHO does not tie to a particular unit. The sensible reading is that two Thai bodies and one international one land within a degree of each other: roughly 26 to 27°C, plus a fan.

How the set-point affects your electricity use

An air conditioner cools until the room reaches the set-point, then eases off. The lower the target, the bigger the gap between indoors and outdoors, and the longer the compressor runs. DEDE's figure is up to 4.5% of the unit's electricity cost per degree; The Nation, reporting EGAT estimates in March 2026, said each degree can reduce consumption by around 3–5%. The two overlap, which is reassuring, but both are estimates. Your saving depends on the room, the insulation, the unit and how often it runs. For a bedroom unit running eight hours a night, a couple of degrees adds up over a month; for a spare room used once a week, it is trivial.

EGAT's release also notes that electricity in Thailand is charged on a progressive rate: the more a household uses, the higher the cost per unit. That is one reason heavy air-conditioner use costs more per unit than light use. We have deliberately not quoted tariff figures, because they change; check your own bill. Running time matters as much as temperature, too, which is why DEDE's advice to cut one hour a day belongs beside the set-point. A timer or "sleep" mode can do more for the bill than agonising over half a degree.

The aim is not the highest number; it is the highest number you can live with all night. The US Department of Energy's Energy Saver guide advises setting the thermostat as high as is comfortable when you are home and awake, and raising it when you are asleep or away. A set-point that leaves you sweating just sends you back to the remote.

Why a fan lets you raise the number

Moving air takes heat from skin faster, which is why a breeze feels cooler than still air at the same temperature. The Energy Saver guide says that using a ceiling fan lets you turn up the thermostat about 4°F, roughly 2°C, without a loss in comfort. ENERGY STAR's ceiling fan guidance adds the practical points: ceiling fans cool people, not rooms, so switch them off when nobody is there, and adjust the thermostat when you use one.

A Thai study fits the picture. A field survey of 300 people in air-conditioned buildings in Songkhla, in hot, humid southern Thailand, found a neutral operative temperature of 26.3°C, with an acceptable range of 25.6 to 27.1°C. The authors report that air movement played a key role in improving thermal sensation and preference, while relative humidity had a smaller effect. It covers buildings in general, not bedrooms, but it is a Thai data point, and it sits inside the 26–27°C range the agencies recommend.

What "comfortable" depends on

Your body does not respond to air temperature alone. ASHRAE describes its thermal comfort standard, Standard 55, as covering four environmental factors (temperature, thermal radiation, humidity and air speed) and two personal ones (activity and clothing), and aims at conditions satisfactory for a majority of occupants, not everybody. In a Bangkok flat that means a west-facing wall that has soaked up the afternoon sun can radiate heat into a 26°C room, a fan changes how cool you feel without changing the temperature, a thin sheet and a thick duvet are very different setups, and cooking or working at a laptop adds heat. This is a practical argument for tuning rather than copying a number: 26–27°C is the sensible place to begin, and these other factors explain why your ideal might be a degree either side.

Best temperature for sleeping

Sleep is where people most often over-cool. The honest starting point is that we have not found an official Thai bedtime set-point from DEDE, EGAT or any other Thai authority, so here is what the evidence says and what follows from it.

The Sleep Foundation's guide to the best temperature for sleep reports that most doctors recommend about 65–68°F (15.6–20°C) and explains why: core body temperature falls as you prepare for sleep and reaches its low in the early morning, and a cooler room supports that drop. It also says a higher core temperature is associated with less slow-wave, restorative sleep and lower subjective sleep quality, that hot surroundings appear to reduce REM sleep, and that cold bedrooms are less harmful than hot ones.

Two things stop you applying that range in Bangkok. The guidance is general and written for cooler climates, and reaching 18°C in a condo would take a very low set-point and a high bill. And the wider evidence is about association: a 2024 systematic review in Sleep Medicine Reviews of real-world studies from around the world found that, as a rule, people sleep worse and for less time when it is hotter, indoors or out, and that heat hits sleep hardest on the hottest days, among vulnerable groups and in the warmest regions. The takeaway is not a magic figure; it is that heat disturbs sleep and that Bangkok is where it matters most.

Our suggestion, which is practical advice rather than a research finding:

1. Start at 26°C with a light cover and, if it does not disturb you, a fan on low.
2. If you wake sweaty, drop one degree for a few nights. If you wake chilled or with a dry throat, raise it one degree.
3. Use the timer or "sleep" function if your remote has one, so the unit eases off once you are asleep. Behaviour varies by brand, so check your manual.
4. Angle the louvres away from the bed.

Our guide to bedroom air conditioner hygiene and sleep goes further on airflow direction, dry throat and keeping bedroom air clean overnight.

Humidity matters as much as temperature

Humid air at 26°C feels very different from dry air at 26°C, because sweat evaporates more slowly and your body struggles to shed heat. That is why a sticky 25°C room can feel worse than a dry 27°C one, and why people lower the temperature when humidity is the real problem.

Humidity matters for health and home as well as comfort. The US EPA advises keeping indoor relative humidity below 60%, and ideally between 30% and 50%, and says to keep air conditioning drip pans clean and drain lines unobstructed. The Sleep Foundation's guide to humidity and sleep says high humidity can increase wakefulness and reduce time in deep and REM sleep, and that mould and dust mites both thrive in damp bedrooms.

An air conditioner is also a dehumidifier: water condenses on the cold coil and runs to the drain. That works only if airflow across the coil is good and the drain is flowing, which is one reason a neglected unit leaves a room clammy. If your room feels damp at a normal set-point, buy a cheap hygrometer (a humidity meter) and read it before you touch the temperature. If it sits well above 60%, the fix is drying the air, not chilling it. Our guide to preventing mould in an air conditioner in Bangkok covers the damp side in more depth.

Fan speed, swing and dry mode

Names and behaviour differ between brands, so your manual has the final word, but these are the common settings.

On dry mode, Daikin explains the intent. In its article on dehumidification, Daikin says its dry mode operates at lower capacity, so it can remove moisture without overcooling the space, and gives 30–50% as the optimal indoor humidity range for comfort and health. Dry mode suits a room that is the right temperature but feels heavy; it is not a dependable way to cool a hot room, and whether it uses less electricity depends on the model. Judge it by how the room feels and what the hygrometer shows.

A common mistake is to treat the lowest setting as a turbo button. Dropping the target to 16°C only changes where the unit stops, so the usual result is a room colder than you wanted and a bill higher than you needed. Set the temperature you want and let the unit get there.

Babies, older relatives and pets

"Higher is better" needs care when the people in the room are not healthy adults.

Babies and young children. Overheating is a recognised concern for babies, and there is no single right number for a nursery in a hot climate. Our guide to AC hygiene for babies, children and elderly relatives suggests a room thermometer, light clothing, airflow kept away from the cot, and a conversation with your paediatrician about your child's room temperature. Do not copy an adult set-point and assume it suits a newborn.

Older adults. Heat is a serious risk for older people: the WHO heat fact sheet asks readers to check regularly on vulnerable people, especially those over 65 or with heart, lung or kidney conditions, a disability, or who live alone. Yet an elderly relative may be uncomfortable in a room that suits you. A moderate temperature, no direct draught and no sudden swings are sensible starting points, and the best test is to ask them and their doctor. If an older person seems confused, unusually drowsy or unwell in hot weather, treat it as a medical question, not a thermostat one.

Pets. The Energy Saver guide reminds readers to be mindful of pets' comfort and safety when raising the temperature. If animals stay home during the day, ask your vet what is appropriate for the species and breed before you switch the unit off or set it high.

Asthma and allergies. A very cold, dry airflow can irritate some people, and a damp room is worse. If symptoms are persistent, or you have asthma attacks or reduced immunity, see a doctor rather than adjusting the air conditioner by trial and error.

Offices, shops and restaurants

The 26–27°C advice was aimed at businesses as well as households, and The Nation's March 2026 report said government offices had been told to use 26°C. For a shop or office, three practical points follow. Measure comfort with the people actually in the room, since ASHRAE's standard aims at a majority of occupants and a restaurant pass, a glass-fronted shop floor and a meeting room do not behave alike. Zone and schedule: raise the set-point or switch off in unused rooms, and start the system shortly before opening rather than running it hard all night. And treat maintenance as the large lever, because units that run all day foul faster, and a coil washed before opening runs better than one coated in months of dust and cooking oil. For multi-unit sites, CoolRova's commercial programme starts with a free survey and a written plan with a fixed per-visit price.

Why a dirty unit makes every setting worse

You can choose the perfect temperature and still lose the saving if the unit struggles to deliver it. A clogged filter, a fouled evaporator coil or a coated blower wheel restricts airflow and slows heat transfer, so the compressor runs longer to reach the same set-point.

The authorities agree. ENERGY STAR's maintenance checklist says a dirty filter can raise energy costs and damage equipment, that dirty coils make the system run longer (increasing energy costs and shortening equipment life), and that a plugged drain can cause water damage and affect indoor humidity. The Energy Saver guide recommends cleaning or replacing filters monthly or as recommended. DEDE's up-to-10% cleaning figure sits beside its 1°C figure: the agency treats cleaning and temperature as two halves of one piece of advice.

The symptoms also look like a set-point problem. If the room never reaches the temperature you chose, cools slowly, smells musty, or the unit never seems to cycle off, changing the setting will not fix it. Our guide to what a dirty air conditioner adds to the electricity bill explains the mechanism, and how often to clean your AC in Bangkok gives a schedule.

CoolRova's standard clean washes the filter, evaporator coil and blower wheel in place inside a sealed wash bag, flushes and tests the drain line, and logs the supply-air temperature before and after, with a before-and-after photo report. That log turns "it feels colder" into a number. It starts from ฿690 for one unit; see pricing for multi-unit rates.

A simple way to find your own number

Run a short experiment over a week.

1. Check the basics first. Rinse the filter, close windows and doors, and make sure nothing blocks the indoor or outdoor unit. If the unit has not been cleaned for months, fix that before judging any setting.
2. Put a thermometer and hygrometer in the room. A cheap digital one is fine. You want the real room temperature and humidity, not the remote's target.
3. Start at 26°C with a fan and live in the room for a couple of evenings.
4. Move one degree at a time. If you are comfortable, try 27°C. If you are too warm, check the humidity before lowering the temperature.
5. Use dry mode only if the room is humid but not hot, and compare how it feels with the hygrometer.
6. Add a timer for bedrooms, then write down the winning combination so everyone in the household uses the same one.

The result will probably land at 26 or 27°C with a fan, which is the point: the agencies' recommendation is not arbitrary. But your version will be tuned to your room and checked against the humidity and the unit instead of guessed.

If you are choosing a new unit, the compressor type changes how running cost relates to set-point; we compare the two in our guide to inverter vs non-inverter air conditioners in Thailand. The Energy Saver guide also notes that an oversized air conditioner performs less efficiently and effectively than a smaller, properly sized one, so size the room before you buy.

When to call a professional

A set-point conversation can only take you so far. Call a technician if:

• the room does not reach the set temperature after a clean filter and a few hours of running;
• cooling used to be fine and has gradually weakened;
• the unit runs without cycling off, or switches on and off every few minutes;
• there is ice on the pipes or coil, or water dripping from the indoor unit;
• the room smells musty when the unit starts, or the louvres show dark growth;
• your electricity bill has climbed without a change in how you use the unit.

Persistent breathing symptoms, asthma attacks or illness in a vulnerable person are matters for a doctor first.

If your unit is due, CoolRova's AC cleaning service covers filter, coil, blower wheel and drain in one visit across all Bangkok BTS and MRT zones. Message us on WhatsApp or use the quote form at /contact, and we will tell you which level of clean the unit needs before you adjust a single degree.