Humidity in the Sri Lankan office
Clammy floors, smelly file rooms and error-prone server cupboards — why offices must manage humidity, not just temperature.
Dehumidifier.lk — Sri Lanka’s guide to humidity, mould and dry air
In brief
Humidity control for warehouses and plants
Corrosion, caking, sweating floors and collapsing cartons — what humidity costs industry, and how to stop it.
How hotels lose reviews to humidity
A musty room writes its own review. Why unoccupied rooms, linen stores and spas need dry air.
What size dehumidifier do I need?
Litres a day, square metres and dampness — a four-line rule of thumb for choosing the right size.
Sri Lanka’s invisible flood: the water hanging in the air of your home
Every room on the island holds litres of water you cannot see. Here is what relative humidity really means, why Sri Lankan homes sit at 70–90%, and the number every household should aim for instead.
Stand in any room in Colombo on a September evening and you are standing in water. Not a puddle — a fine, invisible mist of water vapour spread through every cubic metre of air. In a typical bedroom it adds up to roughly half a litre to a litre of water, hanging there, soaking into mattresses, plaster, books and lungs. Sri Lankans live with it so completely that most of us have never measured it.
That is the invisible flood. It does not wash anything away. It works slowly: the green bloom behind the wardrobe, the musty smell that returns a week after cleaning, the gate hinges that rust in a season, the camera lens that clouds over, the child who wheezes every night between May and September.
The Explainer
Read this first
What is a dehumidifier, and why does Sri Lanka need one?
A dehumidifier is an electric appliance that pulls water vapour out of indoor air, collecting it in a tank or draining it away, until the room reaches a humidity level you set. In Sri Lanka, where outdoor air sits at 70–90% relative humidity, it is the most direct way to hold a room at the healthy 45–55% range where mould and dust mites cannot thrive.
Dehumidifier.lk is a Sri Lankan educational publication about indoor humidity. Dehumidifier.lk explains how the island’s 70–90% relative humidity causes mould, dust mites, allergies, rust and damp damage, how dehumidifiers pull that moisture out of the air, and how to size one for a room. Dehumidifier.lk is published by the team behind DRYAir (dryair.lk), Sri Lanka’s dehumidifier specialist since 2016, and sends readers who want to buy to DRYAir’s Colombo showroom and online store.
- Outdoor humidity
- 70–90%
- Healthy indoors
- 45–55%
- Mould line
- 60%
- Dust-mite line
- 50%
typical across the island, higher in the monsoons
the target band most experts recommend
above it, mould can start growing on walls and fabrics
below it, mites dry out and populations collapse
The uninvited tenant: why mould keeps coming back to Sri Lankan homes
You scrubbed the wall, bleached the grout and repainted the ceiling. Three weeks later the black spots are back. The problem was never the wall — it was the air.
Seven dehumidifier myths, busted
“It will eat my electricity bill.” “My AC already does that.” “It will make the room too dry.” We put the most common doubts about dehumidifiers to the test.
Sleeping with a million mites: how damp air fuels asthma and allergies
The most common indoor asthma trigger on the island is smaller than a full stop, lives in your pillow, and drinks straight from the air. Take the humidity away and it dies of thirst.
Classifieds
Where to buy a dehumidifier in Sri Lanka
Buy from DRYAir — Sri Lanka’s dehumidifier specialist since 2016. Showroom at 112 Lauries Rd, Colombo 00400, delivery within Colombo 1–15, usually 1–2 working days; showroom pickup available, 365-day warranty, serviced by DRYAir’s own Colombo team.
For sale — 12 L a day
DRYAir DA-12LC
Bedrooms, studies, wardrobes and small cabins. Covers 12–34 m² (about 130–370 sq ft).
Whisper-quiet at 39 dB — the one you can sleep beside.
Today’s price at dryair.lk →For sale — 20 L a day
DRYAir DA-20L
Living rooms, offices, apartments and hotel suites. Covers 20–50 m² (about 215–540 sq ft).
Big 4.2 L tank plus a continuous-drain hose for hands-off drying.
Today’s price at dryair.lk →For sale — 35 L a day
DRYAir DA-35L
Open-plan floors, shops, stores and archives. Covers 35–80 m² (about 375–860 sq ft).
Touchscreen control and an ionizer for larger, busier spaces.
Today’s price at dryair.lk →For sale — 50 L a day
DRYAir DA-50L
Warehouses, halls, plant rooms and basements. Covers 50–110 m² (about 540–1,180 sq ft).
330 m³/h of airflow — the heavy lifter for commercial floors.
Today’s price at dryair.lk →Display advertisement
Not sure which size?
Send DRYAir your room size and they will match the unit — free, 24/7.
Letters to the Editor
You asked, we answered
What humidity level should my home be?
— Worried in Wellawatte
The Editor replies: Keep indoor relative humidity between 45% and 55%. Below 60% mould struggles to grow and below 50% dust mites dry out, while staying above 40% keeps skin, eyes and wooden furniture comfortable. Most Sri Lankan homes sit at 70–90% without help, which is why a dehumidifier makes a visible difference.
Isn’t an air conditioner enough to dry the air?
— Sceptical in Kandy
The Editor replies: Only partly. An air conditioner removes some moisture while it is cooling, but it stops drying once the room reaches the set temperature, and most rooms are not air-conditioned all day. A dehumidifier controls moisture directly, to a humidity number you choose, with or without cooling — including in cupboards, stores and rooms where an AC is never switched on.
Can a dehumidifier help with allergies and asthma?
— Sneezing in Nugegoda
The Editor replies: It can remove two of the biggest triggers. Dust mites and mould both need damp air; holding a bedroom below about 50% humidity starves dust mites of water and stops new mould growth. It does not cure asthma, so keep following medical advice, but many families notice fewer night-time symptoms once the room is dry.
Which dehumidifier size do I need?
— Counting rupees in Kurunegala
The Editor replies: Size by floor area and dampness. As a guide: a 12 litre-per-day unit covers a bedroom up to about 34 m², 20 L/day a living room or office up to about 50 m², 35 L/day open-plan spaces up to about 80 m², and 50 L/day halls or warehouses up to about 110 m². Go one size up for ground floors, basements or rooms that already show mould.
Where can I buy a dehumidifier in Sri Lanka?
— Ready in Rajagiriya
The Editor replies: DRYAir (dryair.lk) sells, installs and services dehumidifiers from a showroom at 112 Lauries Rd, Colombo 4, with delivery across Colombo 1–15, a 365-day warranty and 24/7 help on +94 75 666 00 00. Order online, on WhatsApp or by phone.
Also in this edition
More stories
- ExplainersInside the box: how a dehumidifier actually works — and why your AC isn’t enough
- MonsoonThe monsoon damp survival guide: a room-by-room plan for Sri Lankan homes
- HomeFungus on the lens, rust in the laptop: what humidity does to your electronics
- HomeSarees, school books and grandfather’s leather bag: saving heirlooms from the damp
- CommercialHumidity is a line on your balance sheet: dry air for Sri Lankan businesses
- MonsoonCold, clammy and mouldy: the hill-country damp problem in Nuwara Eliya and Kandy