Matching a diffuser to your room size is the single biggest factor in getting consistent, noticeable fragrance without wasting oil. A diffuser rated for a small washroom will struggle in an open-plan living room, and an oversized unit in a small bedroom can make a space smell overpowering. Here’s how to work out what you need.
m² vs m³: what’s the difference?
m² (square metres) measures floor area. m³ (cubic metres) measures the full volume of the room, including ceiling height. Most Airmate diffusers are rated in m³ because scent fills the whole volume of a room, not just the floor. To estimate your room’s volume, multiply its floor area (m²) by its ceiling height – a typical Sri Lankan home has ceilings of roughly 2.7–3m, so a 20m² room is roughly 54–60m³.
Airmate diffuser coverage, side by side
| Diffuser | Coverage | Best for | Price |
|---|---|---|---|
| Home Mate | Up to 50m³ | Bedrooms, home offices | LKR 25,000 |
| Duo Mate | Up to 80m² | Living rooms, larger shared spaces | LKR 40,000 |
| Core Mate | Up to 200m³ | Hotel rooms, reception areas (quietest, most portable) | LKR 80,000 |
| Lite Mate | Up to 300m³ | Washrooms, small offices, salons | LKR 18,000 |
| Pro Mate | Up to 500m³ | Offices, retail outlets, clinics | LKR 35,000 |
A few other things to factor in
- Open-plan vs enclosed: an open-plan living/dining area effectively has a larger “room” than its own footprint suggests, since scent disperses into connected spaces. Size up if your room opens onto a hallway or another room.
- Ceiling height: taller ceilings (common in verandas and older Sri Lankan homes) mean more volume for the same floor area – use the m³ calculation above rather than floor area alone.
- How long you want it running: if you plan to run a diffuser most of the day rather than a few hours, a slightly larger-capacity unit means less frequent refilling.
Quick answers
What size diffuser do I need for a 40m² room?
At a typical 2.7–3m ceiling height, a 40m² room is roughly 108–120m³. Home Mate (50m³) would be undersized; Core Mate (200m³) or Lite Mate (300m³) would comfortably cover it, with Core Mate better suited if you also want quiet, discreet operation.
Can one diffuser scent a whole house?
Not reliably through closed doors and multiple rooms. Each diffuser is rated for a single connected space. For a whole home, most customers run one diffuser per main living area rather than relying on one unit throughout.
Which diffuser should I buy if I’m not sure?
For a single bedroom or home office, Home Mate is the most popular starting point. For anything larger, or if you want app/remote control and a longer battery life away from power, Duo Mate or Core Mate are worth the step up.
See the full specifications, FAQs and running costs for each model on the Diffuser Machines page.
