★ Home odour diagnosis · AC rooms
The bottle has not changed. The temperature, the airflow and your nose all have
Nothing is wrong with the bottle. A reed diffuser is an evaporative device, and evaporation rises with temperature and airflow — an AC lowers one and reorganises the other.
Start here
Cooler air means slower wicking and release, so less fragrance enters the room per hour. The bottle lasts longer and reads quieter. That trade is the whole mechanism.
Temperature
An AC dehumidifies as it cools. Drier air lowers perceived odour intensity, which is why the same room reads louder on a humid evening with the unit off.
Humidity
The unit's circulation moves the scent around the room in a pattern, so it arrives in pulses as the compressor cycles rather than sitting evenly.
Airflow pattern
And adaptation is essentially complete in about twenty minutes, so a steady scent disappears until something changes it — which is exactly what the compressor cycling does.
Your nose
Compensate with reed count and blend choice, not by moving the bottle into the airflow. 50ml from ₹749, 130ml from ₹1,249, six fibre reeds included.
Reeds ₹749 · Sukoon ₹1,899
Nothing is wrong with the bottle. A reed diffuser is an evaporative device, and evaporation rises with temperature and airflow — an AC lowers one and reorganises the other.
Start here
Cooler air means slower wicking and release, so less fragrance enters the room per hour. The bottle lasts longer and reads quieter. That trade is the whole mechanism.
Temperature
An AC dehumidifies as it cools. Drier air lowers perceived odour intensity, which is why the same room reads louder on a humid evening with the unit off.
Humidity
The unit's circulation moves the scent around the room in a pattern, so it arrives in pulses as the compressor cycles rather than sitting evenly.
Airflow pattern
And adaptation is essentially complete in about twenty minutes, so a steady scent disappears until something changes it — which is exactly what the compressor cycling does.
Your nose
Compensate with reed count and blend choice, not by moving the bottle into the airflow. 50ml from ₹749, 130ml from ₹1,249, six fibre reeds included.
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?
Drier: the coil pulls moisture out of the air as it cools, and lower humidity lowers perceived odour intensity.
Moving: the unit's circulation carries scent around the room in a pattern and delivers it in pulses as the compressor cycles — which is also what keeps re-presenting it to a nose that would otherwise adapt to it in twenty minutes.
Cool and longFrom ₹849Capillary wicking carries oil up the fibre; evaporation releases it from the exposed length. Both steps are temperature-sensitive, so a room at 20°C releases materially less per hour than the same room at 31°C. The compensation is not a stronger bottle but more exposed surface — that is what reed count is for. Six reeds is full strength for a room up to roughly 150 sq ft. In a bedroom, four is usually still the right answer even in a cooled room, because sealed rooms accumulate rather than flush. And the payoff for the slower rate is real: the bottle comfortably reaches its stated 6–8 weeks at 50ml, or 14–18 at 130ml.
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.
The bottle is behaving exactly as designed, which is the frustrating part. A reed diffuser is not a device that emits a fixed quantity of fragrance per hour — it is a surface that evaporates at whatever rate the room permits. Switch on an air conditioner and you have changed three of the four variables that rate depends on, in the same second. Temperature falls, humidity falls, air movement rises and reorganises. The fourth variable is your own nose, and that changes too.
Quick answers — read this first
Cooler: evaporation from the reed surface slows, so less fragrance enters the room per hour. Quieter, and the bottle lasts longer.Drier: the coil pulls moisture out of the air as it cools, and lower humidity lowers perceived odour intensity.
Moving: the unit's circulation carries scent around the room in a pattern and delivers it in pulses as the compressor cycles — which is also what keeps re-presenting it to a nose that would otherwise adapt to it in twenty minutes.
The short answer
Short answer: Because a reed diffuser is driven by capillary wicking and evaporation, and evaporation rate rises with temperature and air movement. An air conditioner lowers the temperature and dehumidifies the air, so less fragrance leaves the reeds per hour and less of it registers. Heat and draught mean a stronger throw and a shorter bottle; cool and still means quieter and longer. The AC room is the second case.
Why it comes in pulses: The unit circulates the room's air in a defined pattern, and the compressor cycles on and off. Each change in airflow re-presents the scent to your nose, which would otherwise stop registering it — olfactory adaptation is essentially complete in about twenty minutes for a steady, unchanging smell.
What to do about it: Compensate with reed count and blend choice rather than by moving the bottle into the airflow, which empties it fast and aims it at one wall. Six reeds is full strength for a room up to roughly 150 sq ft; four suits a bedroom. Reed diffusers from ₹749.
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 reed diffuser smell different when the AC is running?
1. Because cooler air slows the evaporation the whole format depends on. Oil climbs the fibre reeds by capillary action and evaporates from the exposed length above the neck. That evaporation is temperature-driven. Drop a room from 31°C to 20°C and you have substantially reduced the energy available at that surface, so less material enters the air per hour. The bottle is not weaker; the room is asking less of it. The compensation is that a 50ml which might run down quickly in a hot still afternoon room will comfortably reach its 6–8 weeks in an air-conditioned one.
2. Because drier air changes what you perceive, independently of what is there. An evaporator coil dehumidifies as it cools — that is what the drain pipe is carrying away. Humidity raises perceived odour intensity and dry air lowers it, which is why every room in an Indian city smells stronger on a muggy evening than on a dry one. So the AC is doing two things in the same direction at once: putting less fragrance into the air and making what is there register less. That combination is usually the bulk of the difference people notice.
3. Because the airflow reorganises where the scent actually is. With the unit off, fragrance rises gently from the reeds and spreads by slow convection, so it settles into a soft gradient with the strongest zone near the bottle. With the unit on, the room has a circulation pattern: a jet across the room, a return along the floor, and back to the intake. The scent gets folded into that pattern, so the place where you notice it moves. People often report the room smelling of nothing where the bottle is and distinctly of it three metres away.
4. Because the compressor cycling keeps re-presenting it to your nose. Olfactory adaptation is essentially complete in about twenty minutes: a constant, unchanging smell stops registering, because the sense is built to detect change. Every time the compressor and blower change state, the airflow at your face changes and the scent is delivered as a change rather than a constant — so you notice it again. That is why an AC room often gives you the impression of a diffuser coming and going rather than simply being on.
5. And the character can shift, not only the volume. The lightest molecules in a blend are the most temperature-sensitive, so a bright citrus-led composition loses some of its lift in a cold room while the heavier, more grounded material continues to read. A blend can therefore seem not just quieter but different in an air-conditioned bedroom — which is a genuine reason to choose Evening Calm or Mountain Breeze for a cooled room rather than something that depends on top-note sparkle.
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 drier air changes what you perceive, independently of what is there. An evaporator coil dehumidifies as it cools — that is what the drain pipe is carrying away. Humidity raises perceived odour intensity and dry air lowers it, which is why every room in an Indian city smells stronger on a muggy evening than on a dry one. So the AC is doing two things in the same direction at once: putting less fragrance into the air and making what is there register less. That combination is usually the bulk of the difference people notice.
3. Because the airflow reorganises where the scent actually is. With the unit off, fragrance rises gently from the reeds and spreads by slow convection, so it settles into a soft gradient with the strongest zone near the bottle. With the unit on, the room has a circulation pattern: a jet across the room, a return along the floor, and back to the intake. The scent gets folded into that pattern, so the place where you notice it moves. People often report the room smelling of nothing where the bottle is and distinctly of it three metres away.
4. Because the compressor cycling keeps re-presenting it to your nose. Olfactory adaptation is essentially complete in about twenty minutes: a constant, unchanging smell stops registering, because the sense is built to detect change. Every time the compressor and blower change state, the airflow at your face changes and the scent is delivered as a change rather than a constant — so you notice it again. That is why an AC room often gives you the impression of a diffuser coming and going rather than simply being on.
5. And the character can shift, not only the volume. The lightest molecules in a blend are the most temperature-sensitive, so a bright citrus-led composition loses some of its lift in a cold room while the heavier, more grounded material continues to read. A blend can therefore seem not just quieter but different in an air-conditioned bedroom — which is a genuine reason to choose Evening Calm or Mountain Breeze for a cooled room rather than something that depends on top-note sparkle.
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 reed diffuser evaporates at whatever rate the room allows, and an AC lowers the temperature, dries the air, reorganises the circulation and pulses the airflow. Less fragrance leaves the reeds, less of it registers, it sits somewhere different, and it arrives in bursts. Compensate with reed count and blend choice, not by moving the bottle into the vent.
After the cause is dealt with
SOSA reed diffusers From ₹749
A cooled room is the kind reeds like: slower evaporation, longer bottle life, a steadier background. A SOSA reed diffuser is 50ml from ₹749 for 6–8 weeks or 130ml from ₹1,249 for 14–18, six fibre reeds included — and reed count is the volume dial, so you can tune it without moving the bottle.
Four variables, all changed by one switch
It is worth separating what happens in the room from what happens in your nose, because both are real and they push in the same direction. In the room, two things govern how much fragrance a reed diffuser puts into the air: the exposed surface area of the reeds, which you control with reed count, and the conditions at that surface, which are temperature and air movement. Heat and draught mean a stronger throw and a shorter bottle life; cool and still means a quieter one that lasts longer. An air-conditioned bedroom is cool and — if the bottle is placed sensibly, away from the vent stream — relatively still. So it is, by design, the quiet-and-long end of that trade. That is not a defect; it is one of the reasons a 50ml bottle reaches its 6–8 weeks in a cooled room and can fall short of it on a hot balcony-side table.
In your nose, two further things change. The first is humidity: moist air raises perceived odour intensity, and an evaporator coil is pulling water out of your room air the entire time it cools. The same quantity of fragrance simply reads lower in dry air, which is also why a monsoon evening makes every smell in a flat — good and bad — more present. The second is adaptation. Your sense of smell reports change rather than steady state, and it goes quiet on a constant stimulus within roughly twenty minutes. In a still room a diffuser therefore seems to fade after you have been sitting there a while, then reappear when you come back in from outside. An air conditioner cycling on and off interrupts that constancy repeatedly, which is precisely why the scent seems to come and go rather than simply being present.
Rate, perception and pattern — the three effects separated
1
EFFECT ONE · THE RATE AT THE REED
Less leaves the bottle per hour
Cool and longFrom ₹849Capillary wicking carries oil up the fibre; evaporation releases it from the exposed length. Both steps are temperature-sensitive, so a room at 20°C releases materially less per hour than the same room at 31°C. The compensation is not a stronger bottle but more exposed surface — that is what reed count is for. Six reeds is full strength for a room up to roughly 150 sq ft. In a bedroom, four is usually still the right answer even in a cooled room, because sealed rooms accumulate rather than flush. And the payoff for the slower rate is real: the bottle comfortably reaches its stated 6–8 weeks at 50ml, or 14–18 at 130ml.
The rule: heat and draught, stronger and shorter. Cool and still, quieter and longer. Neither is a fault.
2
EFFECT TWO · WHAT YOUR NOSE DOES WITH IT
Dry air, and a sense built for change
Two separate things. Humidity raises perceived odour intensity, so the dehumidified air of a cooled room makes the same amount of fragrance read quieter — the reverse of the monsoon effect, where every smell in the flat becomes more present. And olfactory adaptation is essentially complete in about twenty minutes for an unchanging stimulus, which is why you cannot smell your own home and why a diffuser seems to disappear while you sit with it. The compressor cycling on and off keeps changing the airflow at your face, and each change restores the scent to attention. That is the pulsing people describe, and it is happening in the nose as much as in the room.
The honest test: step out for thirty minutes and judge the first breath back in. That is the only reading of your own room that means anything.
3
EFFECT THREE · WHERE THE SCENT ENDS UP
The room now has a circulation pattern
With the unit off, fragrance leaves the reeds slowly and spreads by gentle convection, strongest near the bottle and thinning outward. With the unit on, the room has a defined flow: a jet from the louvres across to the far wall, a return along the floor, and back up to the intake grille. The scent is folded into that loop, so the strongest zone is no longer beside the bottle — it is somewhere along the circulation path, often several metres away. This is worth knowing before you conclude the diffuser has stopped working: walk the room rather than judging from one chair. It is also the reason not to move the bottle into the airflow to "help" — that empties it fast and aims it at one wall.
Symptom to cause: reading a diffuser in a cooled room
Most of these are the format behaving correctly in changed conditions. Two of them are not, so it is worth going down the list rather than assuming.
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 |
|---|---|---|---|
| Noticeably quieter with the AC on than off ★ | Lower temperature slowing evaporation, and drier air lowering perceived intensity | Compare the same room on a hot evening with the unit off and a cooled one | Add reeds rather than moving the bottle; six full strength, four in a bedroom |
| Comes and goes in waves rather than sitting steady | Compressor cycling changing the airflow, plus adaptation resetting each time | Note whether the waves line up with the unit starting and stopping | Nothing to fix — this is your nose reporting change rather than steady state |
| Strong across the room but faint right beside the bottle | The room's circulation pattern has moved the scent along the airflow loop | Walk the room slowly instead of judging from one seat | Leave the bottle where it is, out of the jet; walk-test before adjusting anything |
| Smells different in character, not just weaker | Lighter top notes are the most temperature-sensitive and lose lift in a cold room | Smell the bottle neck directly and compare with the room air | Choose a blend that holds in cool air — lavender, pine and cedar, coffee and vanilla |
| Bottle emptying far faster than 6–8 weeks at 50ml | It is sitting in the vent stream or in direct sun — airflow and heat both accelerate it | Check whether the reeds move visibly when the unit is running | Move it out of the airflow, off sunny sills, and drop to four reeds |
| A musty note underneath the fragrance whenever the unit runs | A wet coil, loaded filter or blocked drain — not a fragrance problem | Run fan-only, then cooling, and compare; check the drain runs steadily outside | Wash the filter and service the coil first. Do not scent over it. |
| If none of these fit: half-full bottle, wet reeds, and still faint everywhere? The reeds have clogged with saturated fibre over the weeks. Replace the reeds rather than the liquid, and flip them as a stopgap. | |||
Shop this guide
Choosing a blend that holds up in a cooled room
Reeds · always-on roomsFrom ₹749Shop → Sukoon · when you want a switch₹1,899Shop → Hotel Collection · the scentFrom ₹299Shop →
The SOSA principle
Evaporation is mostly a temperature and airflow story, and the AC rewrites both.
Less fragrance leaves the reeds, drier air makes less of it register, and the circulation puts what remains somewhere other than beside the bottle.
How to compensate properly
First, decide whether anything actually needs fixing. Walk the room with the AC running instead of judging from one chair, because the circulation may have moved the scent several metres from the bottle. Then do the honest test: leave the flat for thirty minutes and judge the first breath on your return, since adaptation is essentially complete within twenty and you are the least reliable judge of a room you have been sitting in. Very often the diffuser is performing perfectly and the reading was taken from the wrong place by the wrong nose.
Second, if it is genuinely too quiet, add exposed surface rather than airflow. Reed count is the volume dial: six fibre reeds is full strength and suits a room up to roughly 150 sq ft, four is the usual bedroom setting, two or three is enough in a small bathroom. Add two reeds and give it three days before judging — the headspace in a room takes time to build, particularly a cool one. What not to do is move the bottle into the vent stream, which empties it in a fraction of its rated life, aims the scent at one wall and couples it to anything the coil is emitting. And if the throw has faded while the bottle is still half full, the reeds have clogged: replace the reeds, not the liquid.
Third, choose for the conditions rather than fighting them. Cool air is unkind to bright, top-heavy compositions and generous to grounded ones, so a cooled bedroom suits Evening Calm — Kashmir lavender and chamomile — or Mountain Breeze with Himalayan pine, sage and cedar, better than a citrus-led blend that depends on lift. Fresh Brew, Coorg coffee and Kerala vanilla, also reads well in cold air. If what you want is presence on demand rather than a constant background, the Sukoon at ₹1,899 with three to six drops of a water-based Hotel Collection scent from ₹299 covers roughly 270–320 sq ft and gives you a switch — its output does not depend on room temperature in the same way. The two liquids are not interchangeable.
Same bottle, same room, different air — and evaporation is mostly a temperature story.
— Sonal Sahani, SOSA
The order that works
If there is a musty note under the fragrance, stop and clean the unit first. If there is not, this is simply a tuning exercise and it is free.
The order that works
Confirm the unit is clean, then tune with reeds
| Step | What to do | When | Cost |
|---|---|---|---|
| 1. Remove the source | Check the vent itself smells of nothing — wash the filters and service the coil if there is any musty note | Before anything else | ₹0 |
| 2. Move the air | Cross-ventilate ten minutes twice a day; a cooled room is sealed and accumulates whatever you put into it | Daily, five to ten minutes | ₹0 |
| 3. Deal with what holds it | Walk the room to find where the scent actually sits; flip or replace clogged reeds; keep the bottle out of the jet | Weekly to monthly | ₹0 |
| 4. Then the always-on layer ★ | A SOSA reed diffuser — a steady background that lasts longer in a cool room — six reeds full strength, four in a bedroom | 50ml 6-8 weeks · 130ml 14-18 | from ₹749 |
| 5. Or the on-demand layer | Sukoon with a Hotel Collection scent — presence on demand across roughly 270–320 sq ft, with output that is less dependent on room temperature | 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
People assume a diffuser that reads quieter in an air-conditioned room is a weaker diffuser, and it is usually the opposite: it is the same bottle being asked for less by a colder, drier room, and it will last longer for exactly that reason. The trade is real and it goes both ways. A hot still afternoon room will make the same 50ml sing and then run out early.
The mistake that follows is moving the bottle into the airflow to compensate. Please do not. You will spend it in a fraction of its life, you will scent one wall rather than the room, and if the coil is doing anything at all you will end up with the two smells permanently joined in your head. Use reed count instead — it is free, it is reversible, and it is what the six reeds in the box are actually for.
And choose for the temperature. Cold air is hard on bright top notes and kind to grounded ones, which is why lavender and chamomile, or pine and cedar, hold their shape in a cooled bedroom while something citrus-led can read thin. It is a small adjustment that makes a bigger difference than most people expect. A portion of every order funds a girl's classroom through Nanhi Kali.
Frequently asked questions
Why does my reed diffuser smell different when the AC is running?
Because evaporation from the reeds depends on temperature and air movement, and the AC changes both. Cooler air releases less fragrance per hour, and the coil dehumidifies as it cools, which lowers perceived odour intensity as well. On top of that, the unit's circulation moves the scent along a defined airflow loop, so the strongest zone is often several metres from the bottle rather than beside it.
Does an AC make a reed diffuser last longer?
Yes, generally. Heat and draught mean a stronger throw and a shorter bottle life; cool and relatively still means a quieter one that lasts longer. A 50ml rated at 6 to 8 weeks will comfortably reach that in a cooled bedroom, where the same bottle on a hot sunlit table could run down early. The quieter reading is the price of the longer life, and reed count is how you adjust the balance.
Why does it seem to come and go in waves?
Two things together. The compressor cycles on and off, changing the airflow at your face each time, and your sense of smell reports change rather than steady state — adaptation to a constant scent is essentially complete within about twenty minutes. So every time the unit changes state, the scent is re-presented as something new and you notice it again. Nothing is wrong with the bottle.
Should I add more reeds in an air-conditioned room?
Only if it is genuinely too quiet after a proper test — walk the room rather than judging from one chair, and leave the flat for thirty minutes before assessing. Reed count is the volume dial: six is full strength for a room up to roughly 150 sq ft, four suits a bedroom, two or three a small bathroom. Add two, wait three days, then judge. Do not move the bottle into the vent stream to compensate.
Which blends work best in a cool room?
Grounded compositions, because the lightest molecules are the most temperature-sensitive and lose lift in cold air. Evening Calm with Kashmir lavender and chamomile suits a cooled bedroom, Mountain Breeze with Himalayan pine, sage and cedar holds its shape well, and Fresh Brew with Coorg coffee and Kerala vanilla reads warm against cold air. A citrus-led blend will seem thinner than it does in summer heat.
Tune it with reed count, not with airflow
A cool room asks less of the bottle — and gives you more weeks
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: six for full strength, four for a bedroom. Replace the reeds rather than the liquid when the throw drops. Or the Sukoon at ₹1,899 with a Hotel Collection scent from ₹299 for presence on demand across roughly 270–320 sq ft. 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 fragrance
- Should I put a reed diffuser near the AC? — why the vent empties it rather than spreading it.
- Fragrancing an AC bedroom after the fix — why a cool room needs less, not more.
- Strong in the bedroom, weak in the living room — room volume and reed count.
- Why does my bedroom smell weird when I turn the AC on? — when the unit itself is the source.
- 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.