The test for a zone: a floor is only a separate zone if its vertical connections are genuinely closed — a stair behind a self-closing door in its own lobby, a lift with doors that sit shut. An open galleried stair or an atrium void means two floors are one volume, and should be specified as one.
The direction of the gradient: downwards in strength as you go upwards in the building. The ground-floor arrival carries the signal; every floor above it is set lower than the floor below, and the top floor is set lowest of all, because the top floor accumulates what the whole stack sends up.
The commissioning order: set the arrival zone first, work upwards setting each floor lower than the last, and commission the top floor last and lowest. Then verify the building from the top down rather than the bottom up — and verify it in the evening, not at opening time.
The machine: Vaayu at ₹11,999 for a genuinely closed zone, rated up to 1000 m³ ≈ 2,000–3,000 sq ft. Aangan at ₹25,999, up to 3,000 m³ ≈ 8,000–10,000 sq ft when it is connected to the air system — and only where the air handling genuinely serves the floors you want scented.
The honest gaps: no coverage figure is published for Meenar ₹38,500, which is named as the larger-property option and specified on enquiry. And there is no way to link machines on different floors to one another: no digital integration of any kind is offered on any SOSA machine, so a four-floor scheme is four machines each holding its own written schedule, not one system with a master setting. Say that at the drawing stage rather than at commissioning.
- The straight answer, in five parts
- Why the lift shaft is the most important drawing in the set
- The top-floor problem, and why it only appears by evening
- The building, level by level
- Commissioning downwards: the walk that finds the error
- The scheme in buying order, and the gaps
- A note from Sonal
- FAQs
2. A floor is a zone only if its vertical connections are genuinely closed. Genuinely closed means a door that is shut during opening hours, not a door that is theoretically self-closing. A stair that arrives into its own small lobby behind a door is a boundary. A galleried stair rising out of the lobby into the first-floor lounge is not a boundary; those two levels are one volume of air, and any scheme that treats them as two will produce a step that members read as inconsistency. A closed door is a real boundary; an open void is one volume, however far apart its ends are vertically.
3. Warm air rises through the openings, and the fragrance goes with it. This is the whole mechanism and it is not subtle. A shaft or an open stair is a chimney: air that is a little warmer and a little lighter than the air around it moves upward through the opening continuously, and it carries whatever is dissolved in it. That means a machine on the ground floor is also, quietly, a machine serving the first and second floors, and it is doing so without a schedule, without a setting, and without anybody having specified it.
4. Therefore the gradient runs downwards as the building runs upwards. The arrival level may be legible, because nobody stands in a threshold for three hours and a fresh nose meets it for about fifteen seconds. Each floor above it is set lower than the floor below, because each floor above it is already receiving the stack from everything underneath. The top floor is set lowest of all, and is frequently set to nothing at all — not out of caution, but because on many properties the top floor is fully scented by the building before a machine is switched on. Dose down, not up. That is true horizontally in any club and it is twice as true vertically.
5. Commission the top floor last, and check the building from the top down. The setting that is wrong on the third floor was made on the ground floor, so the third floor is where you will find it. Set the arrival zone, let the building run for a week, then walk in from the car park, take the lift straight to the top and walk down the stairs. Waterless cold-air nebulising is what makes any of this controllable: Vaayu ₹11,999 per zone, Aangan ₹25,999 where the air handling genuinely serves the floors, both shattering undiluted oil into a dry nano-mist with no water, no dilution, no added humidity and no residue. Alcohol-free, phthalate-free, IFRA-compliant, composed in Pune. A portion of every order supports girl-child education through Nanhi Kali.
Why the lift shaft is the most important drawing in the set
A club spread over five floors of a city building looks, on paper, like five separate scenting problems, and it is very nearly never five separate scenting problems. The reason is that the floors are not sealed from one another and were never meant to be. They are joined by a lift shaft, by at least one stair, usually by a feature stair that the architect was proud of, often by an atrium or a double-height bar, and always by service risers carrying pipework and cable. Each of those is a continuous column of air running the height of the property. Air in a vertical column does not sit still. If the air inside the column is even slightly warmer and therefore lighter than the air outside it, it moves upward, and it is replaced from below. That movement is why a stairwell in an old building feels draughty at the bottom and stuffy at the top, and it is why the smell of a kitchen on the ground floor of a residential building reaches the fourth-floor landing.
Fragrance is carried by air, which means fragrance is carried by that column. A machine set to serve a ground-floor lobby is therefore also, continuously and without instruction, serving the stair hall, the first-floor landing, the second-floor landing and whatever is open to them. Nobody specified that. Nobody is monitoring it. And because it is not on anybody’s drawing, when a member on the third floor mentions that the club smells strong, the operations head goes and looks at the third-floor machine — which is the one machine in the building that is not causing the problem. In a multi-floor club, the fragrance you can smell on the top floor was usually paid for on the ground floor. That single sentence saves more money than any specification I could write, because it stops people buying machines for floors that are already being served.
There is a second, less obvious consequence, and it is the one that catches architects rather than managers. Because the column is doing distribution work for free, the upper floors of a multi-floor club often need less equipment than their area suggests, while the ground floor needs its setting chosen with more care than its area suggests, since it is effectively setting the level for several floors at once. This is also the reason I will not publish a machine count for a multi-floor property as a formula, and would be suspicious of anyone who does. A count derived from floor area on a building like this is not a specification; it is a quotation dressed up as engineering. The inputs that actually decide it are the connected volume read off the section, the ceiling heights, which doors are genuinely shut during opening hours, whether the property runs on one air handling unit or several, and the occupied hours of each level. Send those to the contact page and the answer becomes specific to your building.
Vaayu₹11,999Every vertical opening in the building is a route, and the direction of travel is upward for almost all of the day. A lift shaft moves air twice over: by the temperature difference along its height, and mechanically, because a car travelling up a shaft pushes a column of air ahead of it and pulls one behind. A feature stair open to a double-height lobby is worse, or better, depending on your point of view: it is a wide, unobstructed opening with nothing at all to slow the movement. An atrium is the same thing at greater scale. Service risers matter less because they are narrower, but a riser with a loose access panel on each landing is a real path and a surprisingly effective one. The practical consequence is that fragrance introduced anywhere below the top of the stack ends up distributed along the whole of it, unevenly, with the strongest accumulation at the highest point that is not ventilated.
Aangan₹25,999Look at what the top floor of a club usually is. It is the smallest floor plate, because the plant and the terrace have taken part of it. It is the quietest, because it holds the board suite, the private dining room, the committee room, the cigar terrace lounge or the members’ library. It is the least ventilated, because a room used two evenings a week is rarely running the same air change as a lobby that opens and closes all day. And it sits at the top of every chimney in the building. Put those four facts together and you have a space that receives fragrance continuously from below and disposes of it slowly — which is precisely the definition of accumulation. A sealed, still space collects fragrance; a busy, well-ventilated space needs it replaced constantly. The same machine behaves in opposite ways in the two, and in a tall club the two sit one above the other.
Mountain Breeze₹849Walk the building at seven in the evening, when it is busiest, and write down the state of every vertical opening as you actually find it rather than as the drawing describes it. A fire stair behind a closed door, arriving on each floor into its own lobby behind a second closed door, is a genuine boundary, and the floors either side of it can be specified separately. A lift lobby with doors is a boundary. A feature stair open to the rooms at both ends is not a boundary at any hour. And the one that decides most schemes: a fire door wedged, hooked or propped open every evening for staff movement is not a boundary, whatever the door schedule says, and you must specify the building you have rather than the building on the drawing. Two levels joined by an open void take one setting between them, chosen for the level where people sit longest — which is nearly always the upper one.
The top-floor problem, and why it only appears by evening
The most useful thing I can tell a general manager about a multi-floor club is that the fragrance scheme is not stable across the day, and that the instability is vertical. A setting chosen on the ground floor at eleven in the morning, in an empty building with the air handling running hard after the morning purge, can be genuinely correct at that moment and genuinely wrong on the third floor at seven in the evening. Nothing has been changed. Nobody has touched the machine. Four things have simply happened at once, and all four of them push in the same direction.
First, the stack strengthens as the building warms and fills. Every body in the building is a heat source, and so is every light, every piece of kitchen equipment and every laptop on the coworking floor. The warmer the air inside the columns relative to the air around them, the faster it rises, and the more efficiently it carries fragrance upward. The chimney that was idling at eleven is working by seven. Second, the upper floors change from empty to occupied and from ventilated to comfortable. An unoccupied board floor may be running very little air; the same floor with fourteen people in it is being cooled, which moves air around the volume evenly — and air conditioning does exactly that, distributing fragrance through a space beautifully while also removing it faster than a still room would. Which of those two effects dominates depends on the floor, and that is why the evening reading is the only one worth trusting.
Third, the doors change. Evening is when service movement is heaviest, and evening is when the fire door to the stair gets propped for a trolley and stays propped. A boundary that existed at eleven has gone by seven, and two zones have silently become one. And fourth, the day’s load has settled into the soft mass. Carpet, underlay, heavy curtains and upholstery absorb odour through the day and release it slowly afterwards; a multi-floor club with carpeted upper floors is holding some part of the afternoon’s fragrance in the furniture and giving it back in the evening, on top of whatever the machines are currently producing. The consequence is not complicated: the evening on the top floor is the worst case, and the worst case is what the specification must be set for.
I should be careful here about what fragrance can and cannot do, because in a tall old building the vertical routes carry more than fragrance. If your stairwell smells of damp at the bottom and the second-floor landing smells closed, that is a building condition and not a fragrance deficit — moisture, low air change and a great deal of absorbent mass, worked through in that order: find the source, deal with the moisture, get the air changing, clean the absorbent surfaces, and only then consider fragrance. Adding a pleasant odour to an unpleasant one produces a mixture, and members judge the mixture more harshly than the original, because it now reads as concealment. SOSA sells no air purifier and no dehumidifier, and makes no health, air-quality or mould claim of any kind. Fragrance adds fragrance. In a stacked building that is worth stating plainly, because the chimney that distributes your signature scent is the same chimney that distributes the basement.
The building, level by level
This is the table I would take into a house committee for a stacked property. Note that it is organised by level and by vertical connection rather than by room function, because on a multi-floor club the level and the connection decide more than the function does. Note also that three of the rows are silences. A scheme that only lists what it wants to install is a quotation; a scheme that names what it will leave alone is advice.
| Level | What it usually holds | Vertical connection | Setting | What serves it |
|---|---|---|---|---|
| Ground · arrival ★ | Vestibule, lobby, reception, foot of the feature stair | Bottom of every chimney in the building | The signal — clearly perceptible, and chosen knowing it also sets the floors above | Vaayu in the airflow path, away from the stair foot, or an HVAC return |
| First · open to the lobby | Members’ lounge, bar lounge, galleried reading area | Galleried stair or atrium void — not a boundary | One volume with the ground floor; one setting between them, chosen for the seated level | The arrival machine, verified from the gallery rather than from the door |
| First or second · behind doors | Coworking floor, business lounge, meeting suite | Stair and lift behind closed doors — a genuine boundary | A step below the level underneath it | A zone unit set low, or the air system if it serves this floor |
| Any level · circulation | Corridors, lift lobbies, stair halls | The connective tissue, and the chimney mouth | Light and continuous rather than strong and intermittent | Often the best value in the whole scheme — it carries identity between floors |
| Upper · cloakrooms, washrooms | Small closed volumes off the lift lobby | Closed, low connection | Light, and genuinely local | Reeds are appropriate at this scale — a two-metre zone is the actual brief |
| Top · the quiet floor | Board suite, committee room, private dining, terrace lounge | Top of the stack, least ventilated, smallest plate | Lowest in the building, and frequently nothing at all | Commission it last; measure what the stack has already delivered before buying anything |
| Any level · dining and bars | Restaurant, private dining, bar counter, anywhere food is plated | Often the strongest source in the stack, upward | Unscented | Nothing. Extract and air change instead — the kitchen is the fragrance |
| Any level · gym, spa treatment | Gym floor, studios, treatment rooms | Needs its own extract, not the shared stack | Unscented | Air change on the gym floor; the therapist’s own oils in treatment. Scent the wellness reception lightly |
| Any level · boardroom, library | Boardroom, private meeting rooms, heritage library or card room | Small closed volumes, long occupancy | Unscented by default | Carry the identity in the lift lobby outside instead |
Closed zone · Vaayu₹11,999See it → Floors on one AHU · Aangan₹25,999See it → Larger property · Meenar₹38,500See it →
Commissioning downwards: the walk that finds the error
Here is the procedure I would write into a multi-floor club’s scenting specification, and it is deliberately dull, because the interesting part of this subject is the physics and the reliable part is the paperwork. Set the arrival zone first. Choose its intensity in the knowledge that it is also setting a baseline for every floor connected to it, which means choosing it slightly lower than you would for a single-storey club of the same lobby area. Key-lock it and write the setting down. Then leave the building alone for a week. A stacked property takes days, not hours, to reach the state it will actually live in, because soft furnishings on the upper floors have to come to equilibrium with the air arriving from below.
Then work upward, setting each floor lower than the floor beneath it, and commission the top floor last and lowest. The order matters because every setting you make on a lower floor changes the input to every floor above it, so a top-down commissioning order guarantees you will set the top floor twice and be wrong both times. On the top floor, before you fit anything at all, go up and smell it. On a property with an open stair or a generous lift core, the top floor will frequently already be at a level you would be content with, and the correct specification is then a machine you do not buy. On the floors that do need a unit, set it, key-lock it, write the setting down, and record the schedule on paper next to it.
That last point is worth being exact about, because it is where multi-floor schemes differ from single-floor ones in a way nobody expects. There is no digital integration on any SOSA machine. There is no networking, no building-management interface, no automation protocol and no smart-home connection, which means there is no master control that sets four floors at once and no dashboard that shows you the state of the building. Vaayu is controlled from a Bluetooth app or its onboard buttons, at the machine; Aangan is controlled on an intelligent board at the machine, with programmable work and pause cycles and daily schedules, and it has no app and no Bluetooth of its own. The connection Aangan offers to an air handling unit is a genuine and useful mechanical integration — the mist goes into the air the building is already moving — and it is a completely different thing from a digital one. In practice, therefore, a four-floor scheme is four machines, four written settings, four written schedules and one named person who owns the document. That is less elegant than a control panel and, in a club where the night steward has a key ring and an opinion, considerably more robust.
Finally, the verification walk, which is the only part of this a general manager must do personally. Walk it in the evening, not at opening time, because the evening is the worst case and the morning flatters the scheme. Come in from the car park with a nose that has been outside for some minutes. Take the lift to the top with the doors closed. Step out, and judge the top floor on first impression, in the first handful of seconds, before adaptation starts doing its work. Then descend the stairs slowly, pausing on each landing, and note the step at every level. What you are looking for is not a level; it is a monotonic fall — strongest at the bottom, weakest at the top, with no surprises. If the third floor is stronger than the second, you have found a chimney nobody drew. Take a member with you, once. A member who arrives fresh and has no stake in the specification is a better instrument than anyone who has been working on it, including me.
The scheme in buying order — and the gaps
If a multi-floor club asked me to write the purchase order, this is the order I would write it in, and the first two lines involve no purchase at all. The last row is what SOSA does not publish, and it belongs in the table rather than in a footnote, because a committee will find it either way and it is better found here.
| Step | What it is | Why it comes here in the order | Cost |
|---|---|---|---|
| 1. Mark up the section ★ | Every lift shaft, stair, atrium void, double-height space and riser, with the door state as found at seven in the evening | Because the section, not the plan, tells you what is one volume — and a propped fire door cancels a zone the drawing shows | No purchase |
| 2. Decide the unscented levels and rooms | Dining and bars on any floor, the gym floor, spa treatment rooms, the boardroom, a heritage library — and very often the whole top floor | Naming the silences first is what makes the rest of the scheme credible to a chef, a sommelier and a long-standing member | No purchase |
| 3. Vaayu at the arrival level | Up to 1000 m³ ≈ 2,000–3,000 sq ft, in the airflow path but away from the stair foot, or into an HVAC return, key-locked once set | The bottom of the stack sets the baseline for everything above it, so it is the first machine and sometimes the only one | ₹11,999 |
| 4. A week of running, then the evening walk | Lift to the top, judge on first impression, walk down pausing at each landing, record the step at every level | Because the upper floors need days to reach equilibrium, and because the evening is the worst case the specification must survive | No purchase |
| 5. Aangan where several floors share one air system | Up to 3,000 m³ ≈ 8,000–10,000 sq ft on HVAC, 800ml reservoir, under 42 dB, DC 12V at 14W, programmable cycles and daily schedules | Only worth it where the air handling genuinely serves the floors you want scented — check which floors are on which unit before specifying, not after | ₹25,999 |
| 6. Further zone units, upward, each set lower | One per genuinely closed floor that the walk showed to be short, commissioned in ascending order, top floor last and lowest | Because each setting below changes the input above, so an upward order is the only one you do not have to repeat | ₹11,999 each |
| 7. Reeds where a two-metre zone is the brief | Mountain Breeze and the rest, 50ml or 130ml, six fibre reeds in refillable glass | Upper-floor cloakrooms, a secretary’s office, a console on a landing — small closed volumes where a local zone is exactly what is wanted | ₹749–₹1,349 |
| No count, no network, no listed commercial refill: the honest gaps | No machine count is published as a formula for any property, at any height. No coverage figure is published for Meenar ₹38,500, which is the larger-property option specified on enquiry. No digital integration exists on any machine, so floors cannot be linked or controlled centrally. And no purchasable refill oil is listed for the waterless commercial machines — that fragrance is specified and quoted per property | Said plainly, because all four come up on a multi-floor job and a committee that discovers them later stops believing the rest | Quoted |
Versailles
The club that taught me this occupied five floors of a city building, with a stone stair winding up through the middle of it from the lobby to the committee floor. They had put a machine on each floor, sensibly and symmetrically, and they had set each one by standing in the room and deciding it felt about right. Within a month the committee floor at the top had raised the matter formally. The general manager did what anyone would do and turned the top-floor machine down. It made almost no difference, because the top-floor machine was contributing the smallest part of what the committee floor was receiving. Everything else was arriving up the stair.
We switched the top two machines off entirely and left them off for a fortnight. The top floor settled at a level everybody was happy with, supplied by the building rather than by a machine, and two units came out of the property altogether. Then we lowered the lobby setting by one step, because the lobby had been carrying five floors without anyone accounting for it, and the whole building improved — including the lobby, which members began describing as fresh rather than as scented. That word is the one you are chasing, and it comes mostly from air.
The other thing I would say to a committee about a tall building is about who does the judging. Whoever sets these machines will be a member of staff who has been in the building since seven in the morning, and by opening time they have stopped registering the fragrance entirely. On a single floor that produces a room set slightly too strong. In a stack it produces a top floor set considerably too strong, because the error compounds upward. So set it once, turn the key-lock, write the setting and the schedule on paper next to the machine, name one person who may change it, and check the building the way a member experiences it: from outside, in the evening, by lift to the top and down the stairs. Everything we make is composed in Pune, and a part of every order funds a girl’s classroom through Nanhi Kali.
Frequently asked questions
- Scenting 2,000 sq ft and the 5,000 sq ft fork — one zone honestly, then the point where zoning starts.
- The 10,000 sq ft case — the Aangan argument, with the HVAC precondition stated plainly.
- Zoning at 20,000 sq ft — a division exercise rather than a machine-count exercise.
- How many machines a large club needs — the six inputs, and why the honest answer is a method rather than a number.
- One large machine or several zones — the closed-door boundary decides it, not the budget.
- Double-height lobbies and central AC, corridors, lifts and stairs — the volume a plan hides, and where air actually goes.
- When reeds stop being enough — the crossover, in connected volume and dwell time.
- Brand: the SOSA founder story.
SOSA commercial scenting — facts verified August 2026: Vaayu ₹11,999, waterless cold-air nebulising, coverage up to 1000 m³ ≈ 2,000–3,000 sq ft, 400ml refillable sealed tank lasting up to about 90+ days depending on intensity and hours, Bluetooth app plus onboard buttons, run windows of 1h / 4h / 8h / 24h, day selection, adjustable intensity, auto-stop and key-lock, under 38 dB, freestanding, wall-mounted or HVAC-return mounting, DC 12V / 1A at 5W, CE, RoHS and SGS, black and white. Aangan ₹25,999, HVAC or AHU connection or standalone wall-mount or lay-flat, coverage up to 3,000 m³ ≈ 8,000–10,000 sq ft, 800ml reservoir, under 42 dB, DC 12V at 14W, intelligent PCB with programmable work and pause cycles and daily schedules, metal body 3.9 kg at 284 × 125 × 246 mm, black or white, one-year warranty, imported; it has no app and no Bluetooth, and no certifications are published for it. Meenar ₹38,500 is the larger-property option and is specified on enquiry; no coverage figure is published for it here. Ultrasonic machines: Sukoon ₹1,899 at 270–320 sq ft and Boond ₹899 at up to about 150 sq ft. Reed diffusers ₹749–₹849 for 50ml lasting 6–8 weeks and ₹1,249–₹1,349 for 130ml lasting 14–18 weeks, six fibre reeds, alcohol-free, phthalate-free, paraben-free, IFRA-compliant, 0 ppm formaldehyde, heat-stable CCT carrier, refillable glass bottle, tested at 45°C and 85% RH, composed in Pune. The Hotel Collection fragrance oils are water-based and ultrasonic-only at 15ml ₹299, 100ml ₹999 and 300ml ₹1,799; they are not for reed diffusers and not for the waterless commercial machines. No purchasable refill oil is listed for the waterless commercial machines — that fragrance is specified and quoted per property. No digital integration of any kind is offered on any SOSA machine: there is no networking, no building-management interface, no automation protocol and no smart-home connection, and the Aangan HVAC connection is a mechanical one. SOSA publishes no leather fragrance in any format and no tobacco or smoky fragrance for any diffuser. SOSA sells no air purifier and no dehumidifier, and makes no health, air-quality, VOC or mould claim. No dealer programme, reseller margin, trade price, territory or service contract is published. Free shipping above ₹499. A portion of every order supports girl-child education through Nanhi Kali. SOSA is an independent Indian fragrance house; the Hotel Collection scents are SOSA’s own interpretations inspired by the world’s finest hotels, and SOSA is not affiliated with or endorsed by any hotel brand. Prices subject to change — see the live product pages.