Is there any heat involved? No. It is cool mist, with no heating element. The fragrance is never cooked, so its character stays intact and there is no burn risk.
Why can't I just add essential oils? Raw essential and carrier oils are thick and do not blend into water. They sit on the plate and can clog it, which weakens the mist and can damage the unit. SOSA's water-based fragrance disperses evenly instead.
Inside the machine: the 2.4MHz plate
The heart of every SOSA cool-mist diffuser is a small ceramic transducer, a disc that changes shape very slightly when electricity flows across it. Reverse the current millions of times a second and the disc vibrates at ultrasonic speed, around 2.4MHz. That is far above anything you can hear, which is part of why these diffusers are so quiet.
The mist itself has very little push. It drifts up out of the vent and then the room takes over, with the natural movement of air, a ceiling fan, an open door, spreading it. This is why placement matters more than raw power: a diffuser a little above floor level, away from a wall, will scent a room more evenly than one crammed into a corner.
Because there is no heat, the fragrance keeps its shape. A candle or a heated burner can cook off the brightest top notes; a cool-mist diffuser lifts the same balance the perfumer built, from first drop to last.
Why water-based fragrance disperses and raw oils clog
Here is the part people wish they had known before they bought a bottle of essential oil. The whole system depends on the fragrance mixing into water so it can be atomised along with it. SOSA's Hotel Collection is water-based and designed for exactly this: a few drops disperse through the tank and lift out evenly on the mist.
Use only SOSA's water-based Hotel Collection fragrance in these diffusers. Raw essential oils, perfumes and carrier oils are too thick or solvent-heavy, so they can clog the ultrasonic misting plate and damage the unit. An essential oil or a perfume behaves very differently. Oil and water do not mix, so the oil floats as a thick film on the surface, right over the plate. That film is too heavy to atomise, so it damps the vibration, thins the mist, and over time leaves a sticky residue on the disc. Alcohol-based perfumes bring their own problem, with the solvent attacking seals and the plate.
| What you add | What happens on the plate |
|---|---|
| SOSA water-based fragrance | Blends into the water, atomises cleanly, mists across the room, plate stays clear |
| Raw essential or carrier oil | Floats as a thick film, damps the vibration, clogs the disc, weakens the mist |
| Alcohol-based perfume | Solvent can attack seals and the plate; not made for a water tank |
Fill with clean, room-temperature water (filtered or RO in hard-water cities to avoid mineral white dust), never hot water. The mist is cool, with no heat, and it scents a room rather than purifying the air. Think of it this way: the machine is a water atomiser first and a scent machine second. Give it water and a fragrance built for water, and it does its one job beautifully for years.
The SOSA range
SOSA makes three cool-mist ultrasonic diffusers for different rooms, each arriving with three of our water-based Hotel Collection fragrances so you can scent from day one. Prices and headline specs below are live from the SOSA store. Whichever you choose, use only the SOSA water-based fragrance - raw essential or carrier oils can clog the misting plate.
| Diffuser / refill | Character | Best for | From |
|---|---|---|---|
| Boond (300ml mini) | USB · up to 6 hrs · colour night light · ~150 sq ft | Desk, bedside, hostel | ₹799 |
| Sukoon (500ml) | 16-18 hrs · 7-colour LED · remote + 2H/4H timers · 270-320 sq ft | Bedroom, study, nursery | ₹1799 |
| Megh (6L) | Up to 100 hrs · adjustable mist dial · ~35 dB · large-room humidifier | Living room, dry AC, winter | ₹3499 |
| Hotel Collection fragrance | Water-based refill · 7 hotel-inspired scents · 15/100/300ml | Refill for any SOSA diffuser | ₹299 |
Versailles
I trained as a perfumer at ISIPCA in Versailles, but half the questions we get are not about scent at all - they are about the machine. Indian rooms are bone-dry from AC and winter, and most gadget diffusers are too small, too loud, or quit by midnight. So we made three: Boond (300ml, desk), Sukoon (500ml, bedroom, with a remote and mood light) and Megh (6L, whole-room), each shipping with three of our fragrances.
They are cool-mist ultrasonic diffusers - an ultrasonic plate turns water into a fine, cool mist with no heating element, so there is no boiling water or burn risk, and each has an auto shut-off when the tank runs dry.
One thing I say on every listing and will say here: use only SOSA's water-based Hotel Collection fragrance. Raw essential oils, perfumes and carrier oils are thick or solvent-heavy and can clog the misting plate and damage the unit. A few drops of our water-based fragrance in the tank mists cleanly and scents the whole room.
Frequently asked questions
Facts verified June 2026: SOSA makes three cool-mist ultrasonic diffusers: Boond (300ml, USB, colour night light, up to 6 hrs, ~150 sq ft, ₹799), Sukoon (500ml, 7-colour LED, remote + 2H/4H timers, up to 16-18 hrs, 270-320 sq ft, BPA-free, ₹1799) and Megh (6L, adjustable mist dial, ~35 dB, up to 100 hrs, ₹3499). Each is cool mist (no heating element) with auto shut-off, ships with 3 water-based Hotel Collection fragrances (15ml ₹299 / 100ml ₹999 / 300ml ₹1799), and is made for Indian AC-dry and winter air. Use SOSA water-based fragrance only; raw essential or carrier oils can clog the ultrasonic misting plate. Composed in India; a portion of every order supports Nanhi Kali girl-child education. These are independent, hotel-inspired fragrance interpretations created by SOSA. SOSA is not affiliated with, endorsed by or associated with the hotels named; all hotel names are trademarks of their respective owners and are used only to describe the scent style.