Every AC company in Bangkok sells two things: a clean and a deep clean. The prices are different, the names vary — chemical wash, ถอดล้าง, overhaul — and the explanation of why you'd pick one over the other is usually missing. Here it is.
The standard clean, ฿690 per unit
This is the six-monthly service. The unit stays on the wall.
- Power isolated at the breaker. Front cover and filters off.
- The unit is sealed inside a clear wash bag that funnels water into a bucket. Drop sheet on the floor.
- Foaming coil cleaner is applied to the evaporator coil and the blower wheel, left to work, then rinsed at low pressure until the water runs clear.
- The drain pan and drain line are flushed and tested with water.
- The outdoor condenser coil is rinsed where it is reachable.
- Reassembled, run, supply-air temperature and gas pressure logged, before and after photos sent.
About 45 minutes per unit. On a unit that was properly cleaned within the last year, this removes the dust and thin biofilm completely and restores full airflow. Full detail on the AC cleaning page.
The deep chemical wash, ฿1,290 per unit
The unit comes apart.
- Power isolated. Cover, filters, louvres, drain pan and the blower wheel — the long drum behind the coil — are removed from the chassis.
- Each part is foamed, soaked and pressure-washed separately in a tray, where the cleaner can reach between the blower blades and under the pan.
- The coil and housing on the wall are foamed, soaked longer than in a standard clean, and rinsed inside the wash bag.
- An antibacterial, anti-mould treatment is applied to the coil and blower housing.
- Everything is refitted, the blower balanced, the drain flushed and tested, and the unit run and measured.
60–90 minutes per unit. The result is a unit as clean as the day it was installed, and it is the only way to remove the film packed between blower blades — an in-place rinse hits the outer surface and leaves the inside. Full detail on the deep chemical wash page.
How to choose
If you're booking without a technician's opinion, use this:
| Situation | Service |
|---|---|
| Cleaned in the last 12 months, no smell, cooling fine | Standard clean |
| Six-monthly routine service | Standard clean |
| Musty or sour smell on start-up | Deep wash |
| Water dripping from the unit | Deep wash (the pan and coil are shedding sludge) |
| Weak airflow after a standard clean | Deep wash |
| Black specks from the vent, or allergies when the AC runs | Deep wash |
| Not cleaned for 18 months or more | Deep wash |
| Just bought or moved into the unit, history unknown | Deep wash |
If a technician is already there, the rule is simpler: open the cover and look at the blower wheel. Grey with dust, standard clean. Black, deep wash. Our technicians will tell you which before starting and show you the photo.
The pattern most homes settle into
A deep wash once a year, standard cleans in between. For a unit in a bedroom that runs nightly, that is a deep wash each cool season and a standard clean each rainy season, or the other way around. The 4-Visit Year Package is built on exactly this: quarterly visits with one deep wash per unit included. Pet homes, kitchens and short-stay rentals sometimes need the deep wash twice.
What neither one includes
Both services are cleaning. If the unit isn't cold after a clean, that is a diagnostic and repair — capacitor, compressor, sensor, or a refrigerant leak — quoted separately in writing. If the pressures are low, that is a leak test and recharge, not a top-up. A cleaning visit should never end with "and it needed gas" unless gauges were connected and you saw the reading.
Two things to watch for
High-pressure hoses on the coil. The fins are thin aluminium 1.5 mm apart. A pressure washer used at full force on them bends them flat and kills airflow permanently. Coil cleaning is done with foam and a low-pressure rinse.
Acid cleaners. Some cheap services use strong acid to make a coil look bright fast. It corrodes the aluminium and the copper over repeated use. Ask what cleaner is used; the answer should be a biodegradable foaming coil cleaner, rinsed fully out.
Frequently asked questions
What is the difference between AC cleaning and deep cleaning?
A standard clean washes the filter, evaporator coil and blower wheel in place with a foaming cleaner and low-pressure rinse inside a wash bag, and flushes the drain. A deep chemical wash removes the blower wheel, drain pan and louvres from the unit, soaks and strips them separately, cleans the housing, and applies an antibacterial anti-mould treatment. Deep cleaning reaches the packed dirt between blower blades that an in-place rinse cannot.
How often does an AC need a deep chemical wash?
About once a year for a typical Bangkok home, on top of a standard clean every six months. Units in pet homes, kitchens, restaurants and short-stay rentals may need it twice a year. A unit that has gone 18 months or more without service almost always needs a deep wash first.
Is a deep chemical wash bad for the air conditioner?
Not when done properly. The cleaner is a biodegradable foaming coil cleaner rinsed fully out of the unit, and the components are removed and refitted by hand. What damages a unit is a high-pressure hose on the fins, or harsh acid cleaners left to corrode the aluminium — neither is part of a proper deep wash.
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Written by the CoolRova Team
We're Bangkok's documented AC crew — everything we write comes from real cleaning, repair and installation visits across condos, homes and short-stay rentals.
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