Solutions by situation
A 2BHK apartment: the whole setup, in order of value
The problem
A 2BHK is the default Indian urban home and the default target of coverage claims that do not survive contact with a floor plan.
One unit rated for 700 sq ft does not clean a 700 sq ft flat, because air does not move between rooms with the doors shut and, with them open, the unit is fighting the whole volume plus continuous infiltration.
On the water side, apartments add their own complication: the supply reaching your tap has usually been through an underground sump and an overhead tank, and the building's plumbing is a variable you do not control.
What this situation actually needs
Requirements first, in the order they matter. Note that several of these are not products.
Bedroom particulate reduction
Eight continuous hours a night is the largest single exposure block in the day and the easiest room to seal.
H13 HEPA at 4–5 air changes per hour for the bedroom volume, door closed
Kitchen extraction that vents outdoors
Cooking is usually the largest pollution exposure in the home, and a purifier cannot address it.
Ducted chimney, run from before ignition to ten minutes after
Infiltration control
In a leaky flat, outdoor air refills the space as fast as a purifier cleans it.
Door sweeps, sealed unused exhaust openings, window gap sealing
Water characterised at your own tap
Building sump and overhead tank sit between the mains and your kitchen, and both can change the water.
Baseline panel including coliforms, drawn at the kitchen tap
Tank hygiene
An uncleaned tank is a contamination source regardless of the water entering it.
Society tank cleaning on a recorded schedule
The specification
Written as a specification rather than a product name, deliberately. A specification survives a model being discontinued and can be taken to any shop; a product recommendation expires.
| Attribute | Target | Why |
|---|---|---|
| Air — unit count | One per room you actually want treated | CADR does not distribute itself between closed rooms |
| Air — priority room | Master bedroom first, then the second bedroom or living room | Longest continuous occupancy first |
| Air — sizing | Room volume × 4–5 ACH, not the box's coverage figure | Coverage claims are typically calculated at 2 ACH |
| Water — technology | Specified from a test; UV/UF on clean low-TDS supply, RO where TDS or a contaminant requires it | Apartment supply is often municipal and low-TDS, where RO is unnecessary |
| Water — capacity | 8–10 litre storage for a family of four | Covers daily drinking and cooking draw with recovery time |
What to avoid
In every one of these situations there is a purchase that looks obviously right and is wrong.
One large purifier bought to cover the whole flat
It will clean the room it is in and very little else. The coverage figure on the box assumes a sealed volume and two air changes per hour.
RO on low-TDS municipal apartment supply
Below about 200 ppm there is little to remove, and RO discards two to four litres per litre to remove it. UV addresses the risk that actually applies.
Assuming the building's water report describes your tap
The sump and the overhead tank sit in between, and both are common contamination points. Sample at your own kitchen tap.
Buying purifiers before draught-proofing
A few hundred rupees of sealing raises the effectiveness of everything you buy afterwards.
Frequently asked questions
How many air purifiers do I need for a 2BHK?
Do I need RO in an apartment on municipal supply?
Should I test water at the tap or ask the society?
Budget bands are indicative Indian market ranges for planning, last reviewed 2026-08-08. Where this page recommends a test before a purchase, that ordering is deliberate — the specification depends on the result, and a recommendation made without one is a guess wearing a table.