★ SOSA Vaayu · 400ml at eight hours a day
Eight hours a day is the schedule most properties actually need, and it is the one the machine was built to be set to
★ ★ ★ ★ ★
★★★★★
"Eight hours on a timer covering afternoon to late evening. One press, and the ground floor reads the same at eleven at night as it does at five."
Villa · open ground floor
★★★★★
"The month-by-month table is what I printed and stuck inside the cupboard door. I know exactly where I should be at day sixty."
Guesthouse owner
★★★★★
"Running it eight hours instead of continuously made no perceptible difference to the room and a very large difference to the tank."
Duplex · 2,000 sq ft
★★★★★
"Told me the electricity at eight hours a day is under a hundred and fifty rupees a year. That ended a conversation I had been having with my father for a month."
Vaayu ₹11,999
★★★★★
"Clear that no refill is on sale yet, in three separate places. I rang, asked, and made my own decision. That is all I want from a brand."
Boutique property
★★★★★
"We use four hours rather than eight because it is a weekend let. The arithmetic here scales straight across."
Weekend villa let
★★★★★
"Eight hours on a timer covering afternoon to late evening. One press, and the ground floor reads the same at eleven at night as it does at five."
Villa · open ground floor
★★★★★
"The month-by-month table is what I printed and stuck inside the cupboard door. I know exactly where I should be at day sixty."
Guesthouse owner
★★★★★
"Running it eight hours instead of continuously made no perceptible difference to the room and a very large difference to the tank."
Duplex · 2,000 sq ft
★★★★★
"Told me the electricity at eight hours a day is under a hundred and fifty rupees a year. That ended a conversation I had been having with my father for a month."
Vaayu ₹11,999
★★★★★
"Clear that no refill is on sale yet, in three separate places. I rang, asked, and made my own decision. That is all I want from a brand."
Boutique property
★★★★★
"We use four hours rather than eight because it is a weekend let. The arithmetic here scales straight across."
Weekend villa let
✓ Vaayu · 400ml · 1h / 4h / 8h / 24h timers · auto-stop · key-lock · 5W ✓ At 8 hrs a day: about 1.2 kWh a month of electricity — arithmetic on 5W, tariffs vary ✓ No separate Vaayu refill oil is sold today — confirm with SOSA before you buy
Founder Diaries · Large-Space Scenting · The Eight-Hour Day
The daily rate: 4.44 ml a day on the conservative reading, 1.48 ml a day on the generous one. At the conservative figure you are a third of the way through the tank at day thirty.
The electricity: 5W × 8 hours = 40 Wh a day, 1.2 kWh a month, 14.6 kWh a year — roughly ₹88 to ₹146 a year at ₹6 to ₹10 a unit. Arithmetic on the rated wattage, not a bill; tariffs vary by state.
The constraint: no separate Vaayu refill oil is sold at present. Ask SOSA where availability stands before you buy.
Vaayu₹11,999 · 8h timerThe commonest scheduling mistake is to start the window at the moment the room is wanted. A large connected volume does not fill instantly; give it an hour or two of head start. For a home, a window running from mid-afternoon to late evening works better than one starting at seven. For a let property, the window should open before check-in rather than at it — the guest's ninety seconds of arrival is the thing you are actually buying, and it cannot be manufactured after the door opens. And be honest about which hours you are asleep for; scenting a house from midnight to eight is a third of your annual supply spent on nobody.
Vaayu · 1h / 4h / 8h / 24h₹11,999Shop → 
Sukoon · steady / 2H / 4H₹1,899Shop → 
Fresh Brew · no timer at allfrom ₹849Shop →
SOSA Vaayu specifications (verified from the live product page, August 2026): ₹11,999 (the product page displays a rounded ₹12,000). Waterless cold-air nebulisation — pressurised air atomises undiluted fragrance oil into a dry nano-mist; no water, no heat, residue-free. Coverage up to 1000m³, about 2,000–3,000 sq ft. 400ml refillable tank, 90+ days per fill at a mid intensity setting. Bluetooth app plus onboard buttons, 1h / 4h / 8h / 24h timers, adjustable mist intensity, auto-stop and key-lock. Under 38 dB. DC 12V / 1A, 5W. 165 × 80.5 × 215 mm, 0.9 kg, black or white. Freestanding or wall / HVAC mount. CE, RoHS and SGS certified. Ships with four SOSA Hotel Collection fragrances at 100ml each (400ml in total) in one of three combos chosen at checkout. SOSA does not currently sell a separate Vaayu refill oil; the 400ml supplied in the box is the fragrance available at the time of writing, and buyers who need long-term supply should confirm current refill availability with SOSA before purchasing. The cold-air oil supplied with the Vaayu is a different product from the water-based Hotel Collection sold for ultrasonic machines (15ml ₹299 · 100ml ₹999 · 300ml ₹1,799), which must not be used in a Vaayu despite sharing scent names. Other SOSA machines: Boond 300ml ₹899 (~150 sq ft) · Sukoon 500ml ₹1,899 (270–320 sq ft) · Megh 6L ₹3,499 (~215 sq ft — a runtime and humidity machine, not a coverage upgrade) · Aangan ₹25,999 (~8,000–10,000 sq ft) · Meenar ₹38,500 (12,000–18,000 sq ft) · Safar car diffuser ₹3,999. Reed diffusers 50ml ₹749–₹849 (6–8 weeks) · 130ml ₹1,249–₹1,349 (14–18 weeks) · duo sets ₹1,498–₹1,598 · oil-only refills 300ml ₹2,399 / 500ml ₹3,499. Runtime, consumption and coverage figures are manufacturer specifications and vary with intensity setting, run hours, ceiling height, ventilation and season; any per-month or per-day figure in this guide is arithmetic on those specifications, not a measurement. Electricity costs vary by state tariff. No claim is made that scenting affects ratings, reviews, bookings, occupancy, revenue, health, mood or air quality. Free shipping above ₹499. A portion of every order supports girl-child education through Nanhi Kali. Prices subject to change — see the live product pages.
Eight hours a day is the pattern almost every property should actually run, and it is not a coincidence that the SOSA Vaayu has an 8h timer alongside its 1h, 4h and 24h settings. It matches a working day, an evening at home and a guest's waking hours in a rented property, and it is one press to set. This page works that single scenario all the way through — the millilitres, the days, the electricity, the month-by-month checkpoints — rather than giving you another table of possibilities. First, the sentence that belongs at the top of every Vaayu running-cost page: SOSA does not currently sell a separate Vaayu refill oil. The 400ml in the box is the entire cold-air fragrance supply available today, so if long-term supply matters to you, confirm current refill availability with SOSA before spending ₹11,999.
Quick answers — read this first
The headline: at eight hours a day, 400ml lasts somewhere between about 90 days and about 270 days — three months to nine — depending on which reading of the 90-day specification is correct. Budget on three, and treat anything beyond it as a good surprise.The daily rate: 4.44 ml a day on the conservative reading, 1.48 ml a day on the generous one. At the conservative figure you are a third of the way through the tank at day thirty.
The electricity: 5W × 8 hours = 40 Wh a day, 1.2 kWh a month, 14.6 kWh a year — roughly ₹88 to ₹146 a year at ₹6 to ₹10 a unit. Arithmetic on the rated wattage, not a bill; tariffs vary by state.
The constraint: no separate Vaayu refill oil is sold at present. Ask SOSA where availability stands before you buy.
The short answer
Short answer: running a SOSA Vaayu eight hours a day, 400ml should last you at least the specified 90 days and quite possibly closer to nine months. The spread exists because the specification quotes 90+ days per fill at a mid intensity setting without stating the daily hours behind it — read as continuous operation the implied rate is 0.185 ml an hour and eight hours a day gives 270 days; read as an eight-hour day it is 0.555 ml an hour and gives exactly the 90 days quoted.
Why eight hours is the right pattern: a cold-air field takes time to establish in a large volume and then persists for hours after the machine stops, particularly in an air-conditioned home with the doors mostly shut. So eight hours of running buys most of the benefit of twenty-four at a third of the oil. Set it once with the 8h timer, lock it with the key-lock, and stop thinking about it.
Shop: Vaayu ₹11,999 — 400ml, up to 1000m³, 1h / 4h / 8h / 24h timers, adjustable intensity, auto-stop, key-lock, under 38 dB, 5W. For one room instead, Sukoon ₹1,899 running 16–18 hours on low. Reed diffusers from ₹749. Free shipping above ₹499.
In this guide
One press, eight hours
Vaayu · 400ml · ₹11,999
16–18 hrs on low
Sukoon 500ml · ₹1,899
Cannot be scheduled at all
Reed diffusers · from ₹749
Straight answer
How long does 400ml last at eight hours a day?
1. Between about three months and about nine. The Vaayu's specification is 400ml and 90+ days per fill at a mid intensity setting. On the conservative reading — that the 90-day figure already assumes an eight-hour day — eight hours a day gives you exactly 90 days. On the generous reading — that it assumes continuous running — the same schedule gives 270 days. Both follow from the same published pair of numbers.
2. The daily rate, both ways. 400 ÷ 90 = 4.44 ml a day if the conservative reading holds; 400 ÷ 270 = 1.48 ml a day if the generous one does. At 4.44 ml a day you are a third of the way down the tank at day thirty; at 1.48 ml a day you are a third of the way down at day ninety.
3. Budget on ninety days. Plan for the shorter figure, note your own level at day fourteen, and revise upward if your tank is falling more slowly. That is the right way round for a supply you cannot currently replenish.
4. The electricity is genuinely trivial. 5W × 8 hours = 40 watt-hours a day. That is 1.2 kWh a month and 14.6 kWh a year — about ₹88 a year at ₹6 a unit and about ₹146 at ₹10. Arithmetic on the rated wattage; tariffs vary by state and slab and this is not a quotation of anyone's bill.
5. Intensity still outranks the schedule. Eight hours at a high setting will not last as long as eight hours at a low one. If your tank is falling faster than the arithmetic suggests, the dial is the first thing to check, not the timer.
6. The supply position, stated plainly. SOSA does not currently sell a separate Vaayu refill oil. The four 100ml cold-air bottles in the box are 400ml — one tankful — and that is what is available today. Ask SOSA where refill availability stands before you commit.
7. No substitutes. The water-based Hotel Collection at ₹299 / ₹999 / ₹1,799 is made for ultrasonic machines and must not be used in a Vaayu, despite sharing scent names. Reed oil goes in neither.
Made in India, CE / RoHS / SGS certified, and a portion of every order supports girl-child education through Nanhi Kali.
2. The daily rate, both ways. 400 ÷ 90 = 4.44 ml a day if the conservative reading holds; 400 ÷ 270 = 1.48 ml a day if the generous one does. At 4.44 ml a day you are a third of the way down the tank at day thirty; at 1.48 ml a day you are a third of the way down at day ninety.
3. Budget on ninety days. Plan for the shorter figure, note your own level at day fourteen, and revise upward if your tank is falling more slowly. That is the right way round for a supply you cannot currently replenish.
4. The electricity is genuinely trivial. 5W × 8 hours = 40 watt-hours a day. That is 1.2 kWh a month and 14.6 kWh a year — about ₹88 a year at ₹6 a unit and about ₹146 at ₹10. Arithmetic on the rated wattage; tariffs vary by state and slab and this is not a quotation of anyone's bill.
5. Intensity still outranks the schedule. Eight hours at a high setting will not last as long as eight hours at a low one. If your tank is falling faster than the arithmetic suggests, the dial is the first thing to check, not the timer.
6. The supply position, stated plainly. SOSA does not currently sell a separate Vaayu refill oil. The four 100ml cold-air bottles in the box are 400ml — one tankful — and that is what is available today. Ask SOSA where refill availability stands before you commit.
7. No substitutes. The water-based Hotel Collection at ₹299 / ₹999 / ₹1,799 is made for ultrasonic machines and must not be used in a Vaayu, despite sharing scent names. Reed oil goes in neither.
Made in India, CE / RoHS / SGS certified, and a portion of every order supports girl-child education through Nanhi Kali.
TL;DR: at eight hours a day, 400ml runs between about 90 and about 270 days — budget on 90 and check your own level at day fourteen. Electricity for that schedule is roughly ₹88 to ₹146 a year on the rated 5W. And no separate Vaayu refill oil is currently sold, so ask SOSA about supply before you spend ₹11,999.
The timer that suits almost every property
SOSA Vaayu · waterless cold-air nebuliser ₹11,999
1h, 4h, 8h and 24h timers with auto-stop, set from a Bluetooth app or the onboard buttons and held in place by a key-lock so a guest or a well-meaning relative cannot change them. The 8h setting is the one most homes and let properties should live on. A 400ml refillable tank rated at 90+ days per fill at mid intensity, covering up to 1000m³ — pressurised air atomises undiluted oil into a dry nano-mist with no water and no heat. Under 38 dB, DC 12V / 1A at 5W, 0.9 kg, freestanding or wall / HVAC mounted. Four Hotel Collection cold-air fragrances at 100ml each in the box; no separate refill oil is currently sold.
Part one — why eight hours, and which eight they should be
Most owners arrive at the eight-hour day by accident, having tried continuous running and found it wasteful. It is worth arriving at deliberately instead, because the choice of which eight hours turns out to matter almost as much as the number. The governing fact is that a cold-air field takes a while to build in a large volume and then decays slowly once the machine stops. That asymmetry is what makes an intermittent schedule so efficient — you are paying for the build and then living off the decay.
1
WHY EIGHT
It matches how properties are actually occupied
Eight hours is a working day, an evening at home from five to one, or the waking window of a guest in a rented property. It is also, on the arithmetic, roughly the point where the marginal hour stops earning its oil. Going from four hours to eight measurably changes how a large open floor reads across a whole evening; going from eight to sixteen mostly scents a house that is asleep. In a commercial setting the eight-hour day is simply the norm — a shop, a showroom or a lobby runs on trading hours, and there is no reason a home should behave differently. The 8h timer means you set it once rather than remembering to switch anything, and auto-stop means the machine consumes nothing for the other sixteen.
The test: if the room reads correctly at the end of your eight hours, the ninth hour is oil you did not need to spend.
2
WHICH EIGHT
Start before you need it, not when you need it
Vaayu₹11,999 · 8h timerThe commonest scheduling mistake is to start the window at the moment the room is wanted. A large connected volume does not fill instantly; give it an hour or two of head start. For a home, a window running from mid-afternoon to late evening works better than one starting at seven. For a let property, the window should open before check-in rather than at it — the guest's ninety seconds of arrival is the thing you are actually buying, and it cannot be manufactured after the door opens. And be honest about which hours you are asleep for; scenting a house from midnight to eight is a third of your annual supply spent on nobody.
The rule: the window should open before the room is needed and close before the house goes quiet.
3
WHAT IT DOES TO THE NUMBER
Ninety days, or two hundred and seventy
The specification gives 400ml and 90+ days at a mid intensity setting, and does not state the daily hours behind it. If those 90 days already assume an eight-hour day, then eight hours a day is exactly 90 days and the rate is 4.44 ml a day. If they assume continuous running, the implied rate is 0.185 ml an hour, eight hours a day is 1.48 ml a day, and 400ml runs 270 days. I am not going to pick a column and call it fact — I would rather you knew the ambiguity exists, budgeted on the shorter one, and asked SOSA which reading is intended if a commercial plan depends on it. Whichever holds, the intensity setting sits on top of both: eight hours at a high setting will not match eight hours at a low one.
Part two — the eight-hour day, checkpoint by checkpoint
The same schedule tracked through both readings, so you can see at a glance whether your tank is behaving conservatively or generously. Note your own level against this at day fourteen and you will know which column you are living in.
Eight hours a day, tracked
Where a 400ml tank should be at each checkpoint
| Checkpoint | Conservative · used | Conservative · left | Generous · used | Generous · left | What to do here |
|---|---|---|---|---|---|
| Day 14 ★ | 62ml | 338ml | 21ml | 379ml | Read your level. This is the measurement that settles it |
| Day 0 | 0 | 400ml | 0 | 400ml | Fill, set the lowest usable intensity, set the 8h timer, lock it |
| Day 30 | 133ml | 267ml | 44ml | 356ml | One third gone on the conservative track. Adjust intensity now if needed |
| Day 45 | 200ml | 200ml | 67ml | 333ml | Halfway on the conservative track. Decide whether to rotate scent |
| Day 60 | 267ml | 133ml | 89ml | 311ml | Two thirds gone conservatively. Ask SOSA about refill availability |
| Day 90 | 400ml | Empty | 133ml | 267ml | The specification's figure on the conservative reading |
| Day 270 | — | — | 400ml | Empty | The generous reading's endpoint — about nine months |
| The honest caveat: the conservative column runs at 4.44 ml a day and the generous one at 1.48 ml a day; both are arithmetic on the same manufacturer specification — a 400ml tank and 90+ days per fill at mid intensity — under different assumptions about the daily run hours that figure implies, because the specification does not state them. Neither column is a measurement, and neither accounts for your intensity setting, connected volume, ceiling height, ventilation or season, all of which move the real figure. Your day-14 reading beats both. And the constraint around the whole table: SOSA does not currently sell a separate Vaayu refill oil, so the 400ml is today's entire supply — which is exactly why the day-60 row says to ask. | |||||
Shop this guide
Three machines, three relationships with a timer
Vaayu · 1h / 4h / 8h / 24h₹11,999Shop → Sukoon · steady / 2H / 4H₹1,899Shop → Fresh Brew · no timer at allfrom ₹849Shop →
The SOSA principle
You pay for the build and then live off the decay. That is the whole case for a timer.
A cold-air field takes hours to establish in a large volume and hours to fade once the pump stops. Eight hours of running buys most of the benefit of twenty-four, at a third of the oil — which is why a reed diffuser, which cannot be paused, is a different economy entirely.
Part three — when eight hours is the wrong pattern, and the supply question
Three properties should not run this schedule. The first is a weekend let or a holiday home used intermittently. Scenting an empty building eight hours a day is the clearest waste I can think of, and with no separate refill currently on sale it is a waste you cannot correct by buying more. Use the 4h and 1h timers around arrivals instead, and the 400ml will run into years rather than months. The second is a space near the top of the 1000m³ rating. There, eight hours at the intensity that volume demands will not give you the days in the table above — plan on considerably less and treat that as the cost of the coverage you wanted. The third is a property where somebody keeps changing the settings. A schedule only saves oil if it survives contact with the household; use the key-lock, and tell your housekeeping staff what it is for.
Which brings me to the thing I state on every page in this cluster, in as many places as it takes. SOSA does not currently sell a separate refill oil for the Vaayu. The machine ships with 400ml of cold-air fragrance in four 100ml bottles — exactly one tankful — and that is the supply available at the time of writing. There is no refill price for me to quote and I will not estimate one. I will also not point you at the water-based Hotel Collection sold at ₹299, ₹999 and ₹1,799 as a substitute; it is formulated for ultrasonic machines, it shares scent names because the compositions are the same, and it does not go in a nebuliser. If long-term supply matters to your purchase, ask SOSA where refill availability stands on the day you order and treat the answer as a condition of the sale. This is the same honesty we apply to our reed range, where replacement reeds are not sold separately and we say so in the buying guide rather than the small print.
On the electricity, so that the smaller number is complete too. Eight hours a day on the rated 5W is 40 watt-hours a day, 1.2 kilowatt-hours a month and 14.6 kilowatt-hours a year — roughly ₹88 a year at ₹6 a unit, ₹117 at ₹8, ₹146 at ₹10. That is arithmetic on a rated figure rather than a meter reading, tariffs vary considerably by state, discom and consumption slab, and fixed charges and duties are excluded. I include it not because it will change anybody's decision but because a running-cost page that omits the computable number in favour of the uncomputable one is not being straight with you. And the boundary that belongs everywhere in this cluster: a scent machine adds fragrance and does nothing else. It does not purify or filter air, remove odours, or affect anyone's health, sleep, focus or mood. Ventilate first; scent afterwards.
Scenting a house from midnight to eight is a third of your annual supply spent on nobody.
— Sonal Sahani, SOSA
Part four — three ways to cover an eight-hour scenting day
The same eight-hour requirement, met by each format we sell, with the consumable cost stated wherever a published price exists and marked open where one does not.
The eight-hour edit
One schedule, every format, honestly costed
| Format | Up-front | Consumable cost | How it handles an eight-hour day |
|---|---|---|---|
| Sukoon — one normal room ★ | ₹1,899, three 15ml scents included | Water-based Hotel Collection · 15ml ₹299 · 100ml ₹999 · 300ml ₹1,799 | Comfortably — 16–18 hrs on low, with 2H / 4H timers and a remote |
| Vaayu — a whole open floor | ₹11,999, 400ml included | Open — no separate refill oil sold today. Ask SOSA | Built for it: an 8h timer, auto-stop and key-lock. 90–270 days on the tank |
| Boond — a small room or desk | ₹899 | Same Hotel Collection prices as the Sukoon | Needs a top-up — about six hours a fill on a 300ml tank |
| Reed diffuser 50ml — one closed room | From ₹749 | About ₹13–₹20 a day over 6–8 weeks | Cannot be scheduled at all — it runs constantly, by design |
| Reed diffuser 130ml | From ₹1,249 | About ₹10–₹14 a day over 14–18 weeks | Same constant release; size buys duration, never reach |
| Reed diffuser on the 300ml oil refill | ₹2,399 · reuse your own vessel and reeds | About ₹7–₹10 a day over 8–11 months | The cheapest fragrance we sell per day. Reed bottles only |
| Never a coverage answer: Megh | ₹3,499 · 6L · ~100 hrs runtime | Same Hotel Collection prices | Runs long but covers only ~215 sq ft — less than the Sukoon |
Honest notes for buyers: the reed diffuser cost-per-day figures are arithmetic on published SOSA prices and stated bottle life (50ml over 42–56 days, 130ml over 98–126 days, a 300ml refill over roughly 8–11 months) and exclude electricity because reeds use none. The Hotel Collection dose per ultrasonic tank fill is not published, so no per-day figure is given for the Sukoon, Boond or Megh — only the bottle prices, which are verified. Vaayu electricity figures are arithmetic on the rated 5W; tariffs vary by state, discom and slab, and nothing here quotes any household's bill. The 400ml tank and 90+ days per fill are manufacturer specifications at a mid intensity setting. SOSA does not currently sell a separate Vaayu refill oil — the 400ml supplied in the box is the cold-air fragrance available at the time of writing, and buyers who need long-term supply should confirm current availability with SOSA before purchasing. The water-based Hotel Collection is a different product for ultrasonic machines and must not be used in a Vaayu; reed oil goes in neither machine. Warranty, AMC, installation, spare parts and app platform details are unverified — ask SOSA. No health, mood, air-purification or odour-removal claim is made or implied. Free shipping above ₹499, and a portion of every order supports girl-child education through Nanhi Kali.
The format with no schedule and no settings
SOSA Fresh Brew · reed diffuser ₹849 / 50ml
Worth knowing what you are giving up when you buy a timer. A reed diffuser cannot be scheduled — it releases constantly, whether you are in the room or asleep or away for a fortnight, which is exactly why an eight-hour comparison does not apply to it. What it offers instead is simplicity and a fully priced supply: Coorg coffee over Kerala vanilla, the fullest-projecting composition in our range at 9.5 on SOSA's own internal strength scale at six reeds, six fibre reeds per bottle, six to eight weeks on 50ml or 14–18 weeks on the 130ml at ₹1,349. Flip the reeds weekly with gloves, keep it out of direct sun, and stand it on a tray.
SS
ISIPCA
Versailles
Versailles
A note from Sonal
I have written this page around a single schedule because the general version of the question kept producing general answers, and general answers are what people ignore. Eight hours a day is what most properties should run, and once you fix the schedule everything else becomes concrete — a millilitre figure, a checkpoint at day fourteen, an electricity cost you can put in a budget, a decision about which eight hours the window should cover.
The day-14 checkpoint is the part I would most like you to use. Two manufacturers' readings of the same specification differ by a factor of three, and no amount of writing on my part settles which applies to your house. A piece of tape on the tank and a fortnight of patience settles it completely. Everything after that is your number rather than mine, and your number is the one worth planning with.
The last thing, again. We ship 400ml and we do not currently sell a separate cold-air refill for this machine. Please ask us where that stands on the day you buy — the day-60 row in the table above says the same thing, and it says it there on purpose. A reader who knows our supply position before spending ₹11,999 is far better served than one who is sold a fantasy. Everything we make is composed and handmade in small batches in Pune, and a part of every order funds a girl's classroom through Nanhi Kali.
Frequently asked questions
How long does 400ml last at eight hours a day?
Between about 90 days and about 270 — three months to nine. The spread comes from the specification quoting 400ml and 90+ days per fill at mid intensity without stating the daily run hours it assumes. Read as an eight-hour day it gives 90 days at 4.44 ml a day; read as continuous running it gives 270 days at 1.48 ml a day. Budget on 90 and check your own tank level at day fourteen.
How much electricity does eight hours a day use?
On the Vaayu's rated 5W, eight hours is 40 watt-hours a day — 1.2 kWh a month and 14.6 kWh a year. At ₹6 a unit that is about ₹88 a year, at ₹8 about ₹117 and at ₹10 about ₹146. These figures are arithmetic on the rated wattage rather than a meter reading; tariffs vary by state, discom and consumption slab, and fixed charges and duties are excluded.
Which eight hours should I choose?
Start the window an hour or two before the space is actually wanted, because a large connected volume takes time to fill, and close it before the house goes quiet. Mid-afternoon to late evening suits most homes; for a let property the window should open before check-in rather than at it. Scenting a sleeping house from midnight to eight spends a third of your supply on nobody.
Is eight hours better than running it continuously?
For almost every home, yes. A cold-air field takes hours to establish in a large volume and then persists for hours after the pump stops, so eight hours buys most of the benefit of twenty-four at roughly a third of the oil. The 24h timer exists for commercial installations that genuinely need it. In a house it mostly scents rooms that nobody is in.
What do I do when the 400ml is finished?
Ask SOSA, and ask before you buy rather than after. SOSA does not currently sell a separate cold-air refill oil for the Vaayu, so the 400ml supplied in the box is the fragrance available at the time of writing. The water-based Hotel Collection for ultrasonic machines is not a substitute and must not be used in a Vaayu. If uninterrupted long-term supply is essential to you, a Sukoon at ₹1,899 or a reed diffuser from ₹749 has a fully priced consumable behind it.
Large-space scenting · the eight-hour day
Eight hours a day: budget ninety days, and check your tank at day fourteen
The SOSA Vaayu at ₹11,999 runs a 400ml tank rated at 90+ days per fill at mid intensity across up to 1000m³, with 1h / 4h / 8h / 24h timers, adjustable intensity, auto-stop and key-lock, under 38 dB on a rated 5W — about ₹88 to ₹146 a year of electricity at eight hours a day. Four Hotel Collection cold-air fragrances at 100ml each are supplied in the box. No separate Vaayu refill oil is sold at the time of writing, so confirm current availability with SOSA before you commit. Free shipping above ₹499, and a portion of every order supports girl-child education through Nanhi Kali.
See the Vaayu → Sukoon ₹1,899
Continue the read
More on consumption and running cost
- How long can 400ml last in a scent machine? — the same arithmetic at six daily schedules.
- How much does it cost to run a cold-air scent diffuser? — electricity computed, fragrance stated honestly.
- What does whole-home scenting cost per month in India? — three household scenarios, fully costed.
- The complete running-cost and consumption guide — this page and the eight around it, in one place.
- 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, on what an eight-hour daily schedule does to a 400ml tank of cold-air fragrance oil. The 400ml tank, the 90+ days per fill at mid intensity, the 1h / 4h / 8h / 24h timers and the 5W rating are manufacturer specifications. Because the specification does not state the daily run hours behind the days-per-fill figure, two readings are carried throughout — 4.44 ml a day and 1.48 ml a day — and every millilitre, day and rupee figure here is arithmetic on one of those assumptions rather than a measurement. Electricity costs are computed as watts × hours ÷ 1,000, multiplied by an assumed tariff of ₹6 to ₹10 a unit; tariffs vary by state, discom and slab, and fixed charges and duties are excluded. Reed diffuser cost-per-day figures are arithmetic on published prices and stated bottle life. No health, mood, air-purification or odour-removal claim is made or implied.SOSA Vaayu specifications (verified from the live product page, August 2026): ₹11,999 (the product page displays a rounded ₹12,000). Waterless cold-air nebulisation — pressurised air atomises undiluted fragrance oil into a dry nano-mist; no water, no heat, residue-free. Coverage up to 1000m³, about 2,000–3,000 sq ft. 400ml refillable tank, 90+ days per fill at a mid intensity setting. Bluetooth app plus onboard buttons, 1h / 4h / 8h / 24h timers, adjustable mist intensity, auto-stop and key-lock. Under 38 dB. DC 12V / 1A, 5W. 165 × 80.5 × 215 mm, 0.9 kg, black or white. Freestanding or wall / HVAC mount. CE, RoHS and SGS certified. Ships with four SOSA Hotel Collection fragrances at 100ml each (400ml in total) in one of three combos chosen at checkout. SOSA does not currently sell a separate Vaayu refill oil; the 400ml supplied in the box is the fragrance available at the time of writing, and buyers who need long-term supply should confirm current refill availability with SOSA before purchasing. The cold-air oil supplied with the Vaayu is a different product from the water-based Hotel Collection sold for ultrasonic machines (15ml ₹299 · 100ml ₹999 · 300ml ₹1,799), which must not be used in a Vaayu despite sharing scent names. Other SOSA machines: Boond 300ml ₹899 (~150 sq ft) · Sukoon 500ml ₹1,899 (270–320 sq ft) · Megh 6L ₹3,499 (~215 sq ft — a runtime and humidity machine, not a coverage upgrade) · Aangan ₹25,999 (~8,000–10,000 sq ft) · Meenar ₹38,500 (12,000–18,000 sq ft) · Safar car diffuser ₹3,999. Reed diffusers 50ml ₹749–₹849 (6–8 weeks) · 130ml ₹1,249–₹1,349 (14–18 weeks) · duo sets ₹1,498–₹1,598 · oil-only refills 300ml ₹2,399 / 500ml ₹3,499. Runtime, consumption and coverage figures are manufacturer specifications and vary with intensity setting, run hours, ceiling height, ventilation and season; any per-month or per-day figure in this guide is arithmetic on those specifications, not a measurement. Electricity costs vary by state tariff. No claim is made that scenting affects ratings, reviews, bookings, occupancy, revenue, health, mood or air quality. Free shipping above ₹499. A portion of every order supports girl-child education through Nanhi Kali. Prices subject to change — see the live product pages.