★ SOSA for 4BHK and Duplex Show Apartments
A single-level 4BHK is one machine. A duplex is the first honest case for a second one.
★ ★ ★ ★ ★
★★★★★
"Placed it on the console by the entrance. The scent is there when the door opens and out of your head by the time you reach the balcony."
SOSA Vaayu · entrance placement
★★★★★
"In a 2BHK the lowest intensity is plenty. We tried the middle setting for a week and it was far too much for 700 sq ft."
SOSA Vaayu · 2BHK sample flat
★★★★★
"The key-lock matters more than I expected. Buyers bring children and children press everything."
SOSA Vaayu · key-lock
★★★★★
"Under 38dB is honest. You cannot hear it over the split unit in the master bedroom."
SOSA Vaayu · quiet running
★★★★★
"We open every bedroom door 30 minutes before a viewing and the far room now smells the same as the living room."
SOSA Vaayu · 3BHK corridor
★★★★★
"Same fragrance in the gallery and in the flat, different intensity. That was the advice and it was right."
SOSA Vaayu · gallery and flat
★★★★★
"Placed it on the console by the entrance. The scent is there when the door opens and out of your head by the time you reach the balcony."
SOSA Vaayu · entrance placement
★★★★★
"In a 2BHK the lowest intensity is plenty. We tried the middle setting for a week and it was far too much for 700 sq ft."
SOSA Vaayu · 2BHK sample flat
★★★★★
"The key-lock matters more than I expected. Buyers bring children and children press everything."
SOSA Vaayu · key-lock
★★★★★
"Under 38dB is honest. You cannot hear it over the split unit in the master bedroom."
SOSA Vaayu · quiet running
★★★★★
"We open every bedroom door 30 minutes before a viewing and the far room now smells the same as the living room."
SOSA Vaayu · 3BHK corridor
★★★★★
"Same fragrance in the gallery and in the flat, different intensity. That was the advice and it was right."
SOSA Vaayu · gallery and flat
★ The machine a 4BHK sample flat uses
SOSA VaayuOne unit for a single-level 4BHKView ₹11,999
SOSA VaayuA second unit for an enclosed upper levelView ₹11,999
SOSA VaayuSame fragrance, softer upstairsView ₹11,999
✓ A 2,000-3,000 sq ft 4BHK is roughly 570-850m³ - still inside one Vaayu's 1000m³ rating on a single level ✓ A second unit is only for a duplex where the upper level is a separate body of air ✓ Made in India · independent, not affiliated with any hotel · a portion funds girl-child education
Founder Diaries · Commercial Scenting Guides · Sample Flats
Does a duplex show flat need two scent machines? Only if the upper level is a separate body of air. With an open stairwell and shared air-conditioning, one SOSA Vaayu (₹11,999) at the foot of the stairs usually carries both levels, because warm air rises. With a door at the stair head or separate split units upstairs, add a second Vaayu on the upper landing and run it one step softer.
Where should the machines go in a 4BHK show flat? The main unit goes on the entrance-to-living air path, close to where conditioned air enters the main living volume. In a duplex, the second SOSA Vaayu (₹11,999) goes on the upper landing rather than inside a bedroom, so it feeds the upper corridor. Both run the same fragrance, with the upper unit a step lower.
See the SOSA Vaayu Book a scenting plan
Facts verified 24 August 2026 against the live SOSA product pages: the SOSA Vaayu (₹11,999) is a waterless cold-air nebuliser rated to 1000m³, described by the manufacturer as approximately 2,000-3,000 sq ft, with a 400ml refillable tank lasting up to about 75 days depending on intensity and run hours, Bluetooth app and button control, 1h/4h/8h/24h timers, adjustable intensity, operation under 38dB, freestanding or wall and HVAC mounting, auto-stop and key-lock, and CE, RoHS and SGS certification. Scent enhances the ambience and perceived quality of a space; it works alongside proper ventilation and cleaning and is not a substitute for either, and SOSA makes no claim that fragrance alone influences a purchase decision. The hotel-inspired scents are SOSA's own original interpretations; SOSA is an independent brand and is not affiliated with, or endorsed by, any hotel named for reference. Coverage, fragrance usage and running cost depend on the space, settings and hours of use, and are confirmed on a consultation. Prices and availability are subject to change - see the live product pages.
This is the first plan in the range where the honest answer might be two. On a single level, a 4BHK is still one machine. In a duplex, everything depends on whether the upper floor is a separate body of air, and there is a simple test for that.
Quick answers — read this first
How many scent machines does a 4BHK sample flat need? One on a single level. A 2,000 to 3,000 sq ft 4BHK holds roughly 570 to 850m³ of air at a normal ceiling height, which is still inside the SOSA Vaayu's 1000m³ rating (₹11,999). A duplex is the exception: if the upper level is closed off by a door or runs on its own air-conditioning, it is a second body of air and needs its own machine.Does a duplex show flat need two scent machines? Only if the upper level is a separate body of air. With an open stairwell and shared air-conditioning, one SOSA Vaayu (₹11,999) at the foot of the stairs usually carries both levels, because warm air rises. With a door at the stair head or separate split units upstairs, add a second Vaayu on the upper landing and run it one step softer.
Where should the machines go in a 4BHK show flat? The main unit goes on the entrance-to-living air path, close to where conditioned air enters the main living volume. In a duplex, the second SOSA Vaayu (₹11,999) goes on the upper landing rather than inside a bedroom, so it feeds the upper corridor. Both run the same fragrance, with the upper unit a step lower.
The short answer
Short answer: one machine on a single level - a 2,000-3,000 sq ft 4BHK is roughly 570-850m³ against the SOSA Vaayu's 1000m³ rating (₹11,999) - and two only when the flat is a duplex whose upper level is closed off or separately air-conditioned.
The pick: one SOSA Vaayu (₹11,999) on the main living level, plus a second Vaayu on the upper landing of a duplex where the upper floor is a separate air volume.
Next step: send both floor plates and tell us whether the stairwell is open - book a free scenting plan and we will confirm one machine or two.
In this guide
A 4BHK is the first plan where the answer is not automatically one. The deciding question is not the square footage. It is whether the upper level is a separate body of air.
The machine, once for a flat and twice for a duplex
The machine
SOSA Vaayu · ₹11,999
The smaller plan
3BHK sample flats
Get the count checked
Free scenting plan
Straight answer
Does a 4BHK sample flat need one scent machine or two?
On a single level, one. A 4BHK show flat of 2,000 to 3,000 sq ft holds roughly 570 to 850 cubic metres of air at a normal ceiling height, and one SOSA Vaayu (₹11,999) is rated to 1000m³, about 2,000-3,000 sq ft. You are near the top of the band rather than a fraction of it, so placement gets stricter - the machine goes centrally on the air path, close to where conditioned air enters the main living volume, and the intensity moves up to the middle rather than the lowest setting. But it is still one machine. The genuine second-machine case is a duplex or a two-level penthouse, and the deciding question is not the square footage. It is whether the upper level is a separate body of air. Here is the test. Stand at the stair head with the air-conditioning running as it would run during a viewing. If the stairwell is open, the levels share air, and warm air rising will carry fragrance up on its own - one machine placed at the foot of the stairs usually does both floors, and you confirm it by walking the upper landing 45 minutes after switch-on. If there is a door at the stair head, or the upper floor runs on its own split units with the doors shut, that floor is a second volume and no amount of intensity downstairs will fix it. Add a second Vaayu on the upper landing, not inside a bedroom, run the same fragrance, and set it one step softer than the ground floor, because the upper level is smaller and quieter and buyers arrive there after their nose has already adjusted. Schedule both on the app so they start together, 30 to 45 minutes before the first appointment. A free scenting plan will confirm one machine or two from your plans, and a portion of every order supports girl-child education through Nanhi Kali.
Single-level 4BHK: one machine, placed centrally, middle intensity. Duplex: one if the stairwell is open, two if the upper level is closed off or separately air-conditioned.
A 4BHK runs on one SOSA Vaayu - rated to 1000m³, about 2,000-3,000 sq ft, against a flat of roughly 570-850m³. A duplex with an enclosed upper level takes a second unit on the landing, same fragrance, one step softer.
See the SOSA Vaayu ₹11,999 Book a scenting plan
One machine or two
Square footage does not decide it. A separate body of air does.
The machine a 4BHK show flat uses, once or twice
The same machine, ordered once for a single-level 4BHK and twice for a duplex with an enclosed upper floor. The pictures link to the product page so you can confirm the rating against both floor plates.
The main level, 2,000-3,000 sq ft
SOSA Vaayu
Rated to 1000m³ against a single-level 4BHK's roughly 570-850m³. Waterless cold-air nebuliser, 400ml tank lasting up to 75 days, Bluetooth app with 1h/4h/8h/24h timers, adjustable intensity, under 38dB, key-lock.
From ₹11,999
The upper landing of a duplex, one step softer
SOSA Vaayu (second unit)
Order the same machine again only when the upper level is closed off or separately air-conditioned. Same fragrance, lower intensity, same schedule, so the two floors read as one home rather than two scented spaces.
From ₹11,999
Mounted to suit either floor
SOSA Vaayu, wall or HVAC mount
165 x 80.5 x 215mm and 0.9kg, freestanding, wall mounted at about 1.5 metres, or fixed to the HVAC. Waterless, so no damp near veneer, stone or artwork on either level.
From ₹11,999
One machine or two - the test that settles it
Three steps settle a 4BHK: the volume maths for the main level, the stairwell test for a duplex, and how to run a second machine if you genuinely need one.
1
Do the maths for the main level first
2,000 to 3,000 sq ft is 570 to 850 cubic metres
A 2,000 sq ft floor at 10 ft is about 570m³. A 3,000 sq ft floor is about 850m³. Both sit inside a single machine's 1000m³ rating, but not with much to spare, so a 4BHK is where sloppy placement starts to show. Put the machine centrally on the air path rather than tucked by the entrance, and expect to run a middle intensity rather than the lowest. If the main level has a double-height living room, add the extra height to your volume before deciding.
Tip: measure the height too. A 3,000 sq ft floor with a 12 ft ceiling is over 1,000m³ and needs a rethink.
One Vaayu is rated to 1000m³, which covers a single-level 4BHK of 2,000-3,000 sq ft.
See SOSA Vaayu →
2
The stairwell test
Is the upper level a separate body of air?
Run the air-conditioning as it would run during a viewing and stand at the stair head. Open stairwell, shared air, no door: the levels are one volume, warm air rises, and a single machine at the foot of the stairs will usually carry both floors. Door at the stair head, or separate split units running upstairs with bedroom doors shut: that floor is its own volume and nothing you do downstairs will reach it. Confirm either way by walking the upper landing 45 minutes after switch-on, which is the only test that matters.
Because the Vaayu can be wall mounted, the upper unit can go on the landing wall without using a styled surface.
See SOSA Vaayu →
3
If you add a second, run it softer
Same fragrance, same schedule, one intensity step down
Two machines only work as one home if they carry the same fragrance and start together. Order the same scent for both, set both on the app to begin 30 to 45 minutes before the first appointment, and set the upper unit one step below the ground floor. The upper level is smaller, quieter and reached later in the walkthrough, by which point a visitor's nose has already adapted - so matching intensities makes the top floor feel heavier than it is.
Tip: put the upper unit on the landing, never inside a bedroom, or the bedroom becomes the strongest room in the house.
The same Vaayu ordered twice, both with 400ml tanks lasting up to 75 days and both on app schedules.
See SOSA Vaayu →
The SOSA principle
Nobody should buy a second machine because the flat is expensive. You buy a second machine because there is a second body of air, and a closed stair door is the only thing that reliably creates one.
Count air volumes, not bedrooms. A 4BHK on one level is one volume. A duplex might be two.
4BHK sizing - single level and duplex
Four versions of a 4BHK, and the count each one honestly needs.
The SOSA plan
4BHK and duplex sizing - one machine or two
| Your 4BHK | What it needs |
|---|---|
|
A single-level 4BHK of 2,000-2,400 sq ft
|
One SOSA Vaayu (₹11,999), placed centrally on the air path, low to middle intensity. View → |
|
A single-level 4BHK of 2,400-3,000 sq ft
|
Still one machine, but placed centrally rather than by the entrance, and run at a middle intensity. Check the far corner at 45 minutes. View → |
|
A duplex with an open stairwell and shared air-conditioning
|
Usually one machine at the foot of the stairs. Walk the upper landing 45 minutes after switch-on before you decide anything else. View → |
|
A duplex with a door at the stair head, or separate AC upstairs
|
Two machines. The second on the upper landing, same fragrance, one intensity step softer, on the same schedule. View → |
One fragrance across both floors, always. A duplex that smells of one thing downstairs and another upstairs reads as two staged sets rather than one home, which is the same reason we advise against room-by-room scents in should the living room and bedrooms of a sample flat smell different. If you are running two units, the operating detail matters more than the purchase: how to use SOSA Vaayu across a luxury sample apartment covers mounting, pairing and schedules for a large flat. For the smaller plans on the same project, see how many machines a 3BHK sample flat needs, and the sales gallery scenting plan for the site as a whole.
One machine, or two if the upper level is closed
SOSA Vaayu ₹11,999 is rated to 1000m³. Send both floor plates and tell us about the stairwell, and we will confirm the count.
A duplex does not need two machines because it has two floors. It needs two machines if it has two bodies of air, and a door at the stair head is what makes that true.
— Sonal Sahani, SOSA
Running two units well
Same fragrance, same schedule, different intensity - so the duplex reads as one home
The SOSA 4BHK sample flat specification
The same machine, once or twice. The Vaayu is waterless, so there is no damp and no residue on veneer, stone or artwork, it runs under 38dB, and it mounts freestanding, on a wall or to the HVAC. Made in India, and a portion of every order supports girl-child education through Nanhi Kali.
The SOSA 4BHK sample flat specification
One machine on a level, two only across a closed duplex
| Machine | Best for | Why it works | Price |
|---|---|---|---|
|
SOSA Vaayu
|
The main level of a 2,000-3,000 sq ft 4BHK | 1000m³ rating against roughly 570-850m³ of air, placed centrally on the air path, middle intensity, app timers, under 38dB | ₹11,999 View → |
|
SOSA Vaayu
|
The upper landing of an enclosed duplex level | A second unit on the same fragrance, one intensity step softer, on the same schedule so both floors start together | ₹11,999 View → |
A quick word on choosing: two machines is a legitimate answer here, and it is still a decision about air volumes rather than about bedrooms or budget. Do the stairwell test before ordering the second unit. One honest note - fragrance works alongside ventilation and cleaning and cannot cover fresh paint, adhesive, new PVC or damp. Cure and ventilate first. A free scenting plan will confirm the count from your plans.
SS
ISIPCA
Versailles
Versailles
A note from Sonal
Large show flats are where scenting budgets get inflated. A four bedroom apartment feels like it should need four machines, and a duplex feels like it should need six. Neither is true, and buying that way produces an apartment that smells like a series of separately perfumed rooms.
On one level, a 4BHK of 2,000 to 3,000 sq ft is roughly 570 to 850m³ and a single Vaayu is rated to 1000m³. One machine, placed centrally, on a middle setting. The only case where I willingly recommend a second unit is a duplex whose upper floor is genuinely cut off - a door at the stair head, or its own air-conditioning with the doors shut. Then it is two machines, same fragrance, the upper one softer.
Two things I say to every developer selling large homes: a home that smells strongly perfumed reads as staged, so run the flat softer than the sales gallery even when the flat is enormous. And fragrance cannot cover fresh paint, adhesive, new PVC or damp - a newly finished penthouse needs curing and ventilation before it needs scent. Everything is made in India, and a portion of every order supports girl-child education through Nanhi Kali.
Frequently asked questions
How many scent machines does a 4BHK sample flat need?
One on a single level. A 2,000 to 3,000 sq ft 4BHK holds roughly 570 to 850 cubic metres of air at a normal ceiling height, which is inside the SOSA Vaayu's 1000 cubic metre rating, about 2,000 to 3,000 sq ft, at Rs 11,999. Place it centrally on the air path rather than by the entrance.
Does a duplex show flat need two machines?
Only if the upper level is a separate body of air. With an open stairwell and shared air-conditioning, one machine at the foot of the stairs usually carries both floors because warm air rises. With a door at the stair head or separate split units upstairs, add a second unit on the upper landing.
How do I test whether the upper floor needs its own machine?
Run the machine and the air-conditioning as you would during a viewing, then walk the upper landing 45 minutes after switch-on. If the fragrance is clearly present there, one machine is enough. If it is absent or faint, the upper level is a separate volume and needs its own unit.
Should the second machine run at the same strength?
No, one step softer. The upper level is usually smaller and quieter, and a visitor reaches it later in the walkthrough when their nose has already adapted. Matching intensities makes the upper floor feel heavier than the ground floor. Use the same fragrance in both units and start them on the same schedule.
What if the living room is double height?
Add the extra height to your volume calculation before deciding. A 3,000 sq ft floor at 12 ft is over 1,000 cubic metres, which is past a single Vaayu's rating, and that is a case to have checked on a consultation rather than guessed at.
Count bodies of air, not bedrooms
SOSA — Sample Flat Scenting for 4BHK show apartments, duplexes & penthouses
The SOSA Vaayu (₹11,999) is rated to 1000m³, about 2,000-3,000 sq ft, so a single-level 4BHK of roughly 570-850m³ is one machine, and only an enclosed duplex level earns a second. Waterless, under 38dB, key-locked and made in India, and a portion of every order supports girl-child education through Nanhi Kali. Send both floor plates and we will confirm the count before you spend anything.
Book a free scenting plan → SOSA Vaayu · ₹11,999
One more look at the machine and the second-unit case
Continue the read
More from SOSA
Editorial standards & sources
About this guide: Written by Sonal Sahani, ISIPCA Versailles-trained founder and perfumer at SOSA Home & Body. Product recommendations reflect the SOSA range; the planning advice applies to any brand.Facts verified 24 August 2026 against the live SOSA product pages: the SOSA Vaayu (₹11,999) is a waterless cold-air nebuliser rated to 1000m³, described by the manufacturer as approximately 2,000-3,000 sq ft, with a 400ml refillable tank lasting up to about 75 days depending on intensity and run hours, Bluetooth app and button control, 1h/4h/8h/24h timers, adjustable intensity, operation under 38dB, freestanding or wall and HVAC mounting, auto-stop and key-lock, and CE, RoHS and SGS certification. Scent enhances the ambience and perceived quality of a space; it works alongside proper ventilation and cleaning and is not a substitute for either, and SOSA makes no claim that fragrance alone influences a purchase decision. The hotel-inspired scents are SOSA's own original interpretations; SOSA is an independent brand and is not affiliated with, or endorsed by, any hotel named for reference. Coverage, fragrance usage and running cost depend on the space, settings and hours of use, and are confirmed on a consultation. Prices and availability are subject to change - see the live product pages.