★ Home odour diagnosis · AC rooms
Four wet parts in one plastic box on your bedroom wall
"Sometimes" is the important word. An intermittent musty smell tracks a cycle — the compressor, the weather or the drain — and the cycle names the part.
Start here
The evaporator coil is held below dew point while cooling, so it is wet for every hour the unit runs. Dust that gets past the filter embeds between fins two millimetres apart.
The coil
The blower wheel sits downstream of the coil, in the damp part of the casing, and furs up with lint. It is not a user-serviceable part on most splits.
The blower
Condensate falls into a shallow plastic pan and leaves by gravity through a pipe with no trap and no flush. Sludge builds, the line slows, water stands.
Pan and drain
An AC recirculates. Anything the unit emits stays in the bedroom, because a closed room exchanges only about 0.2–0.5 of its air an hour.
No ventilation
Once the unit is serviced and the room aired, a reed diffuser from ₹749 gives the bedroom a settled background. Fragrance adds; it never subtracts.
Reeds ₹749 · Sukoon ₹1,899
"Sometimes" is the important word. An intermittent musty smell tracks a cycle — the compressor, the weather or the drain — and the cycle names the part.
Start here
The evaporator coil is held below dew point while cooling, so it is wet for every hour the unit runs. Dust that gets past the filter embeds between fins two millimetres apart.
The coil
The blower wheel sits downstream of the coil, in the damp part of the casing, and furs up with lint. It is not a user-serviceable part on most splits.
The blower
Condensate falls into a shallow plastic pan and leaves by gravity through a pipe with no trap and no flush. Sludge builds, the line slows, water stands.
Pan and drain
An AC recirculates. Anything the unit emits stays in the bedroom, because a closed room exchanges only about 0.2–0.5 of its air an hour.
No ventilation
Once the unit is serviced and the room aired, a reed diffuser from ₹749 gives the bedroom a settled background. Fragrance adds; it never subtracts.
Reeds ₹749 · Sukoon ₹1,899
✓ Diagnosis first — if the cause is damp, drainage or a filter, fragrance is not the fix ✓ Reeds from ₹749 for always-on rooms · Sukoon ₹1,899 when you want a switch ✓ Composed by an ISIPCA Versailles-trained perfumer · phthalate-free
Founder Diaries · Why does my home smell like this?
Why "sometimes": the smell tracks a cycle. Compressor cycling points at the coil; humid weather points at the coil and pan together; worse after idle days points at the drain.
The habit that helps most: ten minutes of fan-only before every shutdown, so the coil dries instead of sitting wet all night.
Step fourFrom ₹849Thin aluminium fins wrapped around copper tubing, packed a couple of millimetres apart to maximise surface area. Below dew point while cooling, therefore streaming with condensation. Fine dust that gets past the mesh lodges between fins and stays there, wet and undisturbed, and biological growth follows. The tell is timing: the smell appears or strengthens when the compressor engages and eases when it cycles off. A spray cannot fix this, because the deposit is centimetres deep inside a fin pack. A jet clean by a technician before the season is what fixes it; ten minutes of fan-only before shutdown is what slows it coming back.
Reeds · always-on roomsFrom ₹749Shop → 
Sukoon · when you want a switch₹1,899Shop → 
Hotel Collection · the scentFrom ₹299Shop →
SOSA products & prices (verified August 2026): Hotel Collection water-based ultrasonic diffuser fragrance 15ml ₹299 · 100ml ₹999 · 300ml ₹1,799 · Pack of 7 (15ml, all fragrances) ₹1,799; refills 100ml from ₹999. Seven scents: The Ritz-Carlton-inspired (white tea · bergamot · cedar), Westin-inspired (white tea · aloe · cedar), 1 Hotels-inspired (cedarwood · vetiver · green leaves), The St. Regis-inspired (amber · violet · woods), Shangri-La-inspired (jasmine · green tea · white tea), Four Seasons-inspired (citrus · floral · sandalwood), W Hotels-inspired (citrus · pepper · amber). Diffusers: Boond 300ml ₹899 · Sukoon 500ml ₹1,899 · Megh 6L ₹3,499. Water-based, phthalate-free, composed to IFRA standards for home diffusion; 3–6 drops per tank. Made in India, Pune. The Hotel Collection scents are SOSA's own interpretations inspired by the world's finest hotels; all hotel names are trademarks of their respective owners and are used only to describe the scent style — SOSA is an independent Indian fragrance house, not affiliated with or endorsed by any hotel brand. Prices and availability subject to change — see the live product pages.
Open the front cover of a split air conditioner and what you are looking at is a wet machine. A block of aluminium fins running with condensation, a fan wheel sitting in the damp air behind it, a plastic tray catching the runoff and a pipe carrying it out through the wall on nothing but gravity. Four places to hold water, in one box, on your bedroom wall, running most nights for four months a year. A musty smell out of that assembly is not a fault. It is what the design makes possible if nobody cleans it.
Quick answers — read this first
The four parts: the evaporator coil (permanently wet while cooling, fins packed two millimetres apart), the blower wheel (downstream, in the damp zone, furs with lint), the drain pan (shallow, plastic, holds standing water if the line slows), and the condensate line (gravity-fed, no trap, no flush).Why "sometimes": the smell tracks a cycle. Compressor cycling points at the coil; humid weather points at the coil and pan together; worse after idle days points at the drain.
The habit that helps most: ten minutes of fan-only before every shutdown, so the coil dries instead of sitting wet all night.
The short answer
Short answer: Because a split AC has four wet or damp components and at least one of them has grown something. The evaporator coil runs below dew point whenever the unit cools, so it never dries while running; dust that slips past the filter embeds between the fins and grows biofilm. The blower wheel behind it collects lint in the same damp air. The drain pan holds standing water if the condensate line partly blocks.
Why it is intermittent: Because it follows a cycle rather than a constant. If it appears each time the compressor kicks in, the wet coil is the source. If it appears mainly in humid weather, condensation load has risen and both the coil and the pan are wetter. If it is worst after a day or two of not using the room, suspect water standing in the pan and a slow drain line.
Where fragrance fits: After the service, not instead of it. A reed diffuser from ₹749 gives a bedroom a quiet permanent background once the unit is clean. It adds pleasant molecules and removes nothing, so over a live coil smell you would simply have two smells at once.
In this guide
Always-on
Reed diffusers · from ₹749
On demand
Sukoon 500ml · ₹1,899
The scent
Hotel Collection · from ₹299
Straight answer
Why does my split AC sometimes make the bedroom smell musty?
1. Because cooling requires a permanently wet surface. A split AC does not cool by blowing cold air at you from somewhere else. It removes heat from your room's own air by passing it over an evaporator coil held below the dew point. Below dew point means water condenses out of the air onto the metal — that is the drip you hear and the pipe on the outside wall. The consequence is that the coil is wet for every single hour the unit cools, in a warm room, in the dark, with air being dragged across it continuously. That is close to an ideal environment for biological growth, and the smell people describe as dirty socks or wet cardboard is that growth.
2. Because the fins are two millimetres apart and dust gets in there. The mesh filter catches large particles. Fine dust goes through, and lands on wet aluminium where it sticks. Over a season it builds into a deposit deep in the fin pack that you cannot see from the front and cannot reach with a cloth or a spray. This is the single most common reason an otherwise healthy three-year-old unit starts smelling in April: it has never had a proper jet clean.
3. Because the blower wheel lives in the damp part of the casing. Behind the coil sits a long barrel-shaped fan wheel with dozens of narrow blades. It handles the air after it has been chilled and had moisture pulled out of it, so it is in the humid zone, and lint and fine fibre pack into the gaps between the blades. A furred blower both smells and moves less air, which is why a unit with this problem often feels weaker as well as smelling worse. On most split units it is not a part you can clean yourself.
4. Because the drain is a gravity pipe with no trap and no flush. Condensate collects in a shallow plastic pan under the coil and runs out through a pipe that leaves the room through a hole in the wall, sloping downward. Nothing scours that pipe. Algae and sludge accumulate inside it, the flow slows, and water begins to stand in the pan instead of leaving. Standing water a few centimetres from the airflow gives a heavier, flatter, more stagnant smell than coil biofilm, and it is characteristically worse after the room has been unused for a day or two.
5. And the room never gets flushed, which is why it accumulates. A split AC recirculates: room air in, room air out, nothing exchanged with outside. A closed bedroom sits at roughly 0.2–0.5 air changes an hour, so whatever the unit emits stays in the room and concentrates over the evening. Cooling is not airing. Fragrance is not cleaning. Service the unit, air the room, and add a reed diffuser or a Sukoon afterwards as the layer that gives a clean bedroom a character.
Made in India, composed by an ISIPCA Versailles-trained perfumer — and a portion of every order supports girl-child education through Nanhi Kali.
2. Because the fins are two millimetres apart and dust gets in there. The mesh filter catches large particles. Fine dust goes through, and lands on wet aluminium where it sticks. Over a season it builds into a deposit deep in the fin pack that you cannot see from the front and cannot reach with a cloth or a spray. This is the single most common reason an otherwise healthy three-year-old unit starts smelling in April: it has never had a proper jet clean.
3. Because the blower wheel lives in the damp part of the casing. Behind the coil sits a long barrel-shaped fan wheel with dozens of narrow blades. It handles the air after it has been chilled and had moisture pulled out of it, so it is in the humid zone, and lint and fine fibre pack into the gaps between the blades. A furred blower both smells and moves less air, which is why a unit with this problem often feels weaker as well as smelling worse. On most split units it is not a part you can clean yourself.
4. Because the drain is a gravity pipe with no trap and no flush. Condensate collects in a shallow plastic pan under the coil and runs out through a pipe that leaves the room through a hole in the wall, sloping downward. Nothing scours that pipe. Algae and sludge accumulate inside it, the flow slows, and water begins to stand in the pan instead of leaving. Standing water a few centimetres from the airflow gives a heavier, flatter, more stagnant smell than coil biofilm, and it is characteristically worse after the room has been unused for a day or two.
5. And the room never gets flushed, which is why it accumulates. A split AC recirculates: room air in, room air out, nothing exchanged with outside. A closed bedroom sits at roughly 0.2–0.5 air changes an hour, so whatever the unit emits stays in the room and concentrates over the evening. Cooling is not airing. Fragrance is not cleaning. Service the unit, air the room, and add a reed diffuser or a Sukoon afterwards as the layer that gives a clean bedroom a character.
Made in India, composed by an ISIPCA Versailles-trained perfumer — and a portion of every order supports girl-child education through Nanhi Kali.
TL;DR: a split AC holds water in four places — the coil, the blower zone, the drain pan and the condensate line — and an intermittent musty smell comes from whichever of them has grown something. The pattern of "sometimes" tells you which. Service it, dry the coil before shutdown, air the room; scent it afterwards.
After the cause is dealt with
SOSA reed diffusers From ₹749
This comes after the service visit. Once the coil, blower and drain are clean, a SOSA reed diffuser holds a quiet bedroom background with no electricity and nothing to operate — 50ml from ₹749 for 6–8 weeks, 130ml from ₹1,249 for 14–18, six fibre reeds included, four of which is right for a cooled bedroom.
Why a cooling coil is wet by design, not by fault
People are often surprised that dehumidification is not a separate feature of an air conditioner but an unavoidable side effect of how it cools. To pull heat out of air, the coil has to be colder than the air. In an Indian bedroom in May, colder than the air very quickly means colder than the dew point of that air, at which point water stops being vapour and becomes liquid on the nearest cold surface. That surface is your evaporator coil. There is no version of this machine that cools your room without wetting its own coil. Litres of water leave a hard-working split unit through the drain pipe on a humid night, and every drop of it condensed on aluminium fins first.
So the question is never how to stop the coil getting wet — it is how long it stays wet and how much organic material is sitting on it. This is where two things you control make a real difference. The first is the filter: a clean mesh catches lint, hair and larger dust before it reaches the fins, and a filter washed monthly through the season keeps the coil load down substantially. The second is drying time. If you switch the unit off at the wall at midnight with the coil soaked, it stays soaked in a warm dark box until morning. If you run fan-only for ten minutes first, the blower drives most of that moisture off and the coil spends the night nearly dry. Many units have a self-clean or dry mode that does exactly this automatically, and it is worth finding in the manual.
The four wet parts, and how each one behaves
1
PART ONE · THE EVAPORATOR COIL
Wet every hour it runs
Step fourFrom ₹849Thin aluminium fins wrapped around copper tubing, packed a couple of millimetres apart to maximise surface area. Below dew point while cooling, therefore streaming with condensation. Fine dust that gets past the mesh lodges between fins and stays there, wet and undisturbed, and biological growth follows. The tell is timing: the smell appears or strengthens when the compressor engages and eases when it cycles off. A spray cannot fix this, because the deposit is centimetres deep inside a fin pack. A jet clean by a technician before the season is what fixes it; ten minutes of fan-only before shutdown is what slows it coming back.
The tell: clean on fan-only, smelly on cooling. That combination points squarely at the wet coil.
2
PART TWO · THE BLOWER WHEEL
Downstream, damp, and full of lint
The barrel-shaped fan behind the coil is what actually throws air into the room. Because it works the air after it has been chilled and dehumidified, it sits in the damp zone of the casing, and the narrow gaps between its many blades collect fibre, hair and fine dust that packs down into a felt. Two symptoms come together: the unit smells, and it moves noticeably less air than it used to. Shine a torch into the housing with the filters removed and look at the blades — clean plastic or grey fur is usually obvious. On most residential splits this is not a user-serviceable part; the technician has to open the casing, so it belongs on the same service visit as the coil.
The tell: smells in fan-only as well as cooling, and the filters were clean when you checked them.
3
PARTS THREE AND FOUR · THE PAN AND THE LINE
Standing water, and the pipe that should prevent it
Condensate drips off the coil into a shallow plastic tray and leaves through a pipe that runs, by gravity, out through the wall. There is no trap and no flush, so nothing ever scours the inside of that pipe. Over a season algae and sludge narrow it; over two seasons it can partly block. When the flow slows, water stands in the pan a few centimetres from the airflow and stagnates. The smell is heavier and flatter than coil biofilm and, because the standing water goes anaerobic while the room is unused, it is often worst on the first evening back after a couple of days away. Confirm it from outside: with the unit cooling hard, water should be running from the pipe, not merely dripping.
Symptom to cause: which of the four parts is it?
The pattern of when the smell appears is doing most of the diagnostic work here. Note the cycle before you book anything — compressor, weather, or days-since-used.
The diagnosis table
What you notice, what it usually is, and how to be sure
| What you notice | Most likely cause | How to confirm it | What actually fixes it |
|---|---|---|---|
| Rises when the compressor engages, eases when it cycles off ★ | Biofilm on the evaporator coil being rewetted by fresh condensation | Alternate two minutes of fan-only with two minutes of cooling and compare | A jet clean of the coil before the season; fan-dry ten minutes before every shutdown |
| Present in fan-only too, and the filters were clean | Lint and dust packed into the blower wheel in the damp part of the casing | Remove the filters and shine a torch on the fan blades — grey fur or clean plastic | Blower wheel clean at the next service; it is not a user-serviceable part |
| Heavy, flat, stagnant; worst on the first evening after days away | Standing water in the drain pan because the condensate line has partly blocked | With the unit cooling hard, check the outdoor pipe is running, not dripping | Clear the line; confirm it falls continuously; no dips or upward kinks along the run |
| Much worse in monsoon weeks than in dry heat | Higher condensation load keeping coil, pan and line wetter for longer | Compare a humid week with a dry one at the same thermostat setting | Use dry mode for part of the night; service before monsoon rather than after |
| Musty everywhere in the flat, not just in front of the vent | Room-level damp or a fabric reservoir — the AC is stirring it, not making it | Leave the unit off for a full day and judge the room on returning from outside | Air the flat twice daily; wash bedding and curtains; find whatever is quietly wet |
| Damp patch under the unit, or dark speckling on the wall behind it | A leaking drain and mould growth — a building and health issue, not an odour problem | Torch behind and below the indoor unit and along the drain pipe run | Fix the leak and remove the growth before anything else. Do not fragrance this. |
| If none of these fit: check the unit's age and service history. A split that has never had a proper coil clean is due one at around three years in an Indian city, and most intermittent musty smells at that age resolve on the service visit rather than needing anything cleverer. | |||
Shop this guide
Where fragrance comes in — after the service visit
Reeds · always-on roomsFrom ₹749Shop → Sukoon · when you want a switch₹1,899Shop → Hotel Collection · the scentFrom ₹299Shop →
The SOSA principle
Cooling requires a surface colder than the dew point. That surface is never dry.
Which is why the coil, the blower, the pan and the drain line are the four things to interrogate, and why a spray aimed at the front of the unit reaches none of them.
Service, habit, then scent
First, book the service properly and ask for the right things. A standard "AC servicing" visit in most Indian cities means a filter wash and a gas check, which is not what you need. Ask specifically for the evaporator coil to be jet cleaned, the blower wheel to be cleaned, and the condensate drain line to be flushed and checked for fall along its whole run. Book it before the season starts rather than in the middle of the heat, both because you will get an appointment and because the point is to start the summer clean rather than to rescue it in June.
Second, adopt the two habits that keep it clean between services. Wash the mesh filters monthly through the cooling season — under a tap, soft brush, mild soap, dried completely before refitting — and fortnightly if you are on a dusty road. And run the unit on fan-only for the last ten minutes before switching off, so the blower dries the coil rather than leaving it soaked overnight. If your unit has a dry or self-clean mode, that is the same thing automated; find it in the manual and set it. These two habits do more for coil hygiene over a season than anything sold in a can.
Third, air the room, and then scent it. Because the AC exchanges no air at all, open two openings on opposite sides for ten minutes morning and evening — a closed room sits at roughly 0.2–0.5 air changes an hour and the unit does not shift that number. Once the machine is clean and the room is aired, a bedroom is worth giving a character. A reed diffuser from ₹749 runs on capillary action with no electricity and nothing to switch off at 2am; use four reeds rather than six in a cooled room, and place it away from the vent rather than in front of it. If you would rather have scent on demand, the Sukoon at ₹1,899 with three drops of a Hotel Collection scent from ₹299 runs for an hour before bed. Neither of them does anything to a coil, and neither should be asked to.
A split unit holds water in four places, and every one of them is a candidate.
— Sonal Sahani, SOSA
The order that works
One service booking, two habits, ten minutes of open windows a day — and then, last, the layer you actually buy.
The order that works
Service the machine, dry the coil, air the room — then scent
| Step | What to do | When | Cost |
|---|---|---|---|
| 1. Remove the source | Jet clean the coil, clean the blower wheel, flush the condensate line and check its fall — ask for all three by name | Before anything else | ₹0 |
| 2. Move the air | Cross-ventilate ten minutes twice a day; a split AC recirculates and exchanges no outside air at all | Daily, five to ten minutes | ₹0 |
| 3. Deal with what holds it | Wash filters monthly, run fan-only for ten minutes before shutdown, use dry mode on humid nights | Weekly to monthly | ₹0 |
| 4. Then the always-on layer ★ | A SOSA reed diffuser — a quiet permanent background in a cooled bedroom — four reeds, placed away from the vent airflow | 50ml 6-8 weeks · 130ml 14-18 | from ₹749 |
| 5. Or the on-demand layer | Sukoon with a Hotel Collection scent — an hour of scent before bed with a switch; three drops is plenty in a sealed cooled room | Run it when you want it | ₹1,899 |
Honest notes before you buy: the order above is not padding, it is the whole method. Home fragrance is an additive layer — it puts pleasant molecules into the air, it does not remove unpleasant ones. Scenting over a live odour source gives you both smells at once, which reads worse than the original problem, and it removes the signal that was telling you something needed attention. Three causes in particular are never a fragrance problem: visible or suspected mould, which is a health issue and needs the moisture source found and the growth removed; a drain or sewer smell, which usually means a dry P-trap or a failed seal and is a plumbing job; and a gas-like or burning smell, which should be treated as an emergency, not an odour. Persistent damp in a wall or ceiling is a building fault and needs a professional. Once the room is genuinely clean and dry, SOSA reed diffusers run oil-based fragrance with no electricity, while the Sukoon (₹1,899) runs the water-based Hotel Collection — the two liquids are not interchangeable. Reed fragrance is composed and made in India, in Pune; both are phthalate-free and composed to IFRA standards for home diffusion, not for skin or ingestion. A portion of every order supports girl-child education through Nanhi Kali.
The on-demand layer
SOSA Sukoon · 500ml ₹1,899
Once the room is clean and dry, the Sukoon at ₹1,899 gives you scent with a switch — run it for an hour before people arrive rather than all day. It takes 3-6 drops of the water-based Hotel Collection (from ₹299) and covers roughly 270-320 sq ft. A reed diffuser is the opposite trade: no switch, no effort, always on.
SS
ISIPCA
Versailles
Versailles
A note from Sonal
Every year around March I get messages about bedrooms that have started smelling musty, and nearly all of them are about units that have never had a real coil clean. The service most people buy is a filter wash and a gas top-up, and it does not touch the part that smells. Ask for the coil to be jet cleaned, the blower wheel to be cleaned and the drain line to be flushed. Those three words on the booking are worth more than anything on my website.
The habit I would most like to spread is the ten-minute fan-only run before shutdown. It costs nothing, takes no attention once it becomes routine, and it means the coil spends the night dry instead of soaked. Growth needs water and time; you cannot remove the water while the unit is cooling, but you can remove the eight idle hours of it, and that is a large fraction of the problem.
And then scent the room lightly. Air-conditioned bedrooms are sealed, so whatever you put in stays in; they are cool, so evaporation from reeds is slower and steadier. Four reeds of something quiet, placed away from the vent, gives you a room that smells settled rather than perfumed. I would rather sell you a 50ml bottle you use correctly than a 130ml one you put under the airflow. A portion of every order funds a girl's classroom through Nanhi Kali.
Frequently asked questions
Why does my split AC sometimes make the bedroom smell musty?
Because a split unit holds water in four places and one of them has grown something. The evaporator coil runs below dew point while cooling, so it is wet the whole time and collects dust that gets past the filter. The blower wheel behind it sits in the same damp air and furs with lint. The drain pan holds standing water when the condensate line partly blocks. The "sometimes" follows whichever cycle drives the part involved.
Why is it only intermittent rather than constant?
Because it tracks a cycle. If it rises whenever the compressor engages and eases when it stops, the wet coil is the source. If it is far worse in humid weather, the condensation load has risen and coil, pan and line are all wetter for longer. If it is worst on the first evening after a couple of days away, suspect water standing in the drain pan, which goes stagnant while the unit is idle.
Can I clean the coil or blower myself?
Not properly, on most residential splits. The coil fins are packed about two millimetres apart and the deposit sits deep inside the pack, so anything sprayed at the front face reaches almost none of it. The blower wheel is behind the coil and needs the casing opened. What you can do yourself, and should, is wash the mesh filters monthly and run fan-only for ten minutes before shutdown so the coil dries.
How do I check the condensate drain without tools?
Run the unit on hard cooling for twenty minutes, then go and look at the outdoor end of the drain pipe. On a warm humid day water should be running out steadily, not merely dripping. Then check the wall directly under and behind the indoor unit for any damp patch or blistered paint. A blocked line usually shows up as both a weak outdoor flow and a heavier, stagnant smell indoors.
Should I use a fragrance in the room while I wait for the service?
Not over a live coil smell. Fragrance is additive — it puts pleasant molecules in and removes nothing — so you would get both smells arriving on the same air stream, which reads worse than the original. Air the room, run fan-only to dry the coil, and wait for the visit. Afterwards a reed diffuser from ₹749 or the Sukoon at ₹1,899 is genuinely worth having.
After the coil, the blower and the drain
Clean the wet parts first — then give the bedroom a settled character
SOSA reed diffusers composed and made in Pune, 50ml from ₹749 for 6–8 weeks or 130ml from ₹1,249 for 14–18, six fibre reeds included and four the right number for a cooled bedroom. Or the Sukoon at ₹1,899 with a Hotel Collection scent from ₹299 for an hour before bed. Neither does anything to an evaporator coil. A portion of every order supports girl-child education through Nanhi Kali.
Shop SOSA reed diffusers → See the Sukoon ₹1,899
Continue the read
More on air-conditioned rooms and smell
- My room smells fine until I switch on the AC — six tests that isolate the unit.
- Can a dirty AC filter make a clean bedroom smell bad? — a month of dust becoming a smell.
- A Mumbai bedroom that smells damp with the AC running — moisture rather than the machine.
- Fragrancing an AC bedroom after the fix — why a cool room needs less, not more.
- Brand: the SOSA founder story.
Editorial standards & sources
About this guide: Written by Sonal Sahani, ISIPCA Versailles-trained founder and perfumer at SOSA Home & Body. Odour diagnosis here is general building and household guidance, not a substitute for a plumber, an electrician or a damp specialist where one is needed. Fragrance longevity and coverage figures are SOSA's own for the stated products; the underlying principles — sorption into soft materials, air-change rate and olfactory adaptation — are general.SOSA products & prices (verified August 2026): Hotel Collection water-based ultrasonic diffuser fragrance 15ml ₹299 · 100ml ₹999 · 300ml ₹1,799 · Pack of 7 (15ml, all fragrances) ₹1,799; refills 100ml from ₹999. Seven scents: The Ritz-Carlton-inspired (white tea · bergamot · cedar), Westin-inspired (white tea · aloe · cedar), 1 Hotels-inspired (cedarwood · vetiver · green leaves), The St. Regis-inspired (amber · violet · woods), Shangri-La-inspired (jasmine · green tea · white tea), Four Seasons-inspired (citrus · floral · sandalwood), W Hotels-inspired (citrus · pepper · amber). Diffusers: Boond 300ml ₹899 · Sukoon 500ml ₹1,899 · Megh 6L ₹3,499. Water-based, phthalate-free, composed to IFRA standards for home diffusion; 3–6 drops per tank. Made in India, Pune. The Hotel Collection scents are SOSA's own interpretations inspired by the world's finest hotels; all hotel names are trademarks of their respective owners and are used only to describe the scent style — SOSA is an independent Indian fragrance house, not affiliated with or endorsed by any hotel brand. Prices and availability subject to change — see the live product pages.