Mila Air vs Mila Air Mini

The sensor that decides it

Both machines read particulates: PM1, PM2.5 and PM10, which covers dust, pollen, smoke particles and pet dander. Both read temperature, humidity and carbon monoxide.

The full-size Air adds two the Mini does not have:

• A VOC sensor, which detects volatile organic compounds. That is what you would want if the air problem is paint, glue, solvents, cleaning products or a newly fitted kitchen off-gassing.
• A pressure sensor, which tells the machine how blocked the filter actually is rather than counting down a timer. It replaces the filter when it needs replacing, not on a schedule.

If neither of those describes your problem, the Mini reads everything you care about.

Room size and footprint

Mila rates the Air at around 400 square feet at five air changes an hour, and up to about 1,000 square feet at two. The Mini is rated at around 318 square feet at five, and about 714 at two.

Use the first figure for a room you want genuinely clean and the second as the largest space the machine will affect at all.

The Mini is about 30 per cent smaller by floor space, which is the difference between a machine that fits beside a bedside table and one that does not. In a bedroom that often decides it.

What does not differ

Both take the same seven filters, each tuned to a different problem: allergies, pets, smoke, new-build off-gassing and so on. Both run from the same app and work with Apple Home.

Which to buy

For a bedroom or a study, the Mini. For an open-plan living space, or where solvents and off-gassing are the actual concern, the Air.

One good machine in the room where you sleep will do more for you than an underpowered one in a hallway.