The filter configuration is one of the most important differences between home air purifiers. Depending on the model, the system may include a pre-filter, particle or HEPA filtration and an activated-carbon component.

Check the exact specification of each appliance rather than assuming that every air purifier uses the same filter class or efficiency. Different AirgoClean® models and replacement filters can have different filtration characteristics.

A stated filter efficiency refers to the performance of a defined filter under specified conditions. It does not mean that the appliance removes the same percentage of every type of airborne contaminant from an entire room.

Where a formal filter class is stated for a particular model or replacement filter, compare that exact specification. Do not infer a higher HEPA class from product names or from percentage values alone.

Use the manufacturer's recommended room size together with the appliance's stated air volume when comparing models. Larger rooms or spaces with higher ceilings generally contain more air and may require greater circulation capacity.

Real-world performance also depends on ventilation, open doors and windows, occupancy, particle sources and the selected fan stage. Room-size recommendations should therefore be treated as selection guidance rather than guaranteed air-quality results.

Air volume describes how much air an appliance moves over a defined period. Filter efficiency describes how a particular filter performs under specified conditions. A high value in one category does not automatically imply a high value in the other.

Also check whether the published air volume refers to the maximum fan stage. Reduced-speed and night modes normally operate with different airflow and sound characteristics.

Where fitted, an activated-carbon component complements particle filtration by adsorbing selected odours and gaseous contaminants. This can be useful in rooms affected by cooking smells, smoke or other suitable airborne compounds.

The effectiveness of activated carbon depends on the filter design, contaminant concentration, operating conditions and filter condition. It should not be described as removing every odour or gaseous substance.

Selected air purifiers include particle sensors, air-quality indicators and automatic operating modes. Depending on the appliance, the fan speed can respond to the sensor reading without requiring continuous manual adjustment.

These displays are useful for controlling the appliance and observing changes detected by its sensor. Unless explicitly documented as calibrated measurement equipment, they should not be treated as laboratory instruments.

For bedrooms, home offices and frequently occupied living areas, consider operating noise as well as filtration performance. Sound levels can vary between fan stages, so the maximum specification alone does not describe everyday operation.

Check whether the model provides a reduced-speed or night mode if quieter operation is important to you. Balance the selected operating stage with the amount of air circulation required for the room.

Timers, filter-status indicators, automatic modes, touch controls and air-quality displays can make an air purifier easier to use. The available functions differ between models and generations.

Choose features that support your actual routine rather than assuming that every appliance in the range includes the same sensors, display functions or operating programmes.

Air-purifier performance depends on keeping the filtration system in suitable condition. Follow the operating instructions for cleaning any reusable components and replacing filters when required.

Replacement filters must be matched to the exact appliance model and, where relevant, generation or filter variant. Similar product names do not guarantee compatibility or identical filtration performance.

No single value describes the suitability of a home air purifier. Compare the complete appliance and filter specification with your room and preferred way of using the device.

• Check the exact filter stages and stated filter efficiency;
• Compare recommended room size and maximum air volume;
• Consider particle sensors, automatic modes and controls;
• Check operating noise at the relevant fan settings;
• Verify replacement-filter compatibility and maintenance requirements.