Indoor air guides
16 in-depth guides to choosing, sizing, installing and maintaining air purification. Each guide works through the numbers — room volume, clean air delivery rate, filter classes, noise — so you can check a product claim yourself instead of taking it on trust.
How to size an air purifier explains the one calculation that matters most; CADR explained shows how to read the number on the box; and the 12-question buying checklist turns both into a shortlist. For quick numbers, use the air purifier size calculator.
Filtration & technologies
How particle and gas filters work, what the filter classes mean, and which 'active' technologies can add pollutants instead of removing them.
What Is a HEPA H13 Filter and How Does It Work?
Capture mechanisms, the EN 1822 class table, MPPS and why a sealed housing matters as much as the filter.
Filtration & technologiesHEPA H13 vs H14: What Is the Difference?
A tenfold difference in penetration — and why it often matters less in a living room than airflow and sealing.
Filtration & technologiesHow Activated Carbon Filters Help with VOCs and Odors
Adsorption, carbon mass, contact time, humidity — and the gases carbon handles poorly.
Filtration & technologiesIonizers, UV and Ozone: What to Know Before Buying an 'Active' Air Purifier
Ozone generators, ionizers, UV-C and PCO: how they work and how to check that a device does not add pollutants.
Sizing & performance
The numbers behind a purifier: room volume, air changes per hour, CADR and how to plan real rooms such as offices.
How to Size an Air Purifier for a Room
Room volume × air changes per hour = required clean air. Worked examples, target table and common mistakes.
Sizing & performanceCADR Explained: What Clean Air Delivery Rate Really Tells You
How CADR is measured, how to convert CFM to m³/h and the questions the number leaves unanswered.
Sizing & performanceAir Purification for Offices: A Practical Planning Guide
Room-by-room planning with a worked meeting-room example, noise targets and a maintenance plan.
Airflow & placement
An air purifier can only clean the air that reaches it. These guides cover circulation, mixing and where to install a unit.
How Airflow Affects Indoor Air Quality
Mixing, short-circuiting and the decay equation — plus a home test to measure real performance.
Airflow & placementWhere Should an Air Purifier Be Installed?
Clearances, sources, short-circuiting and room-specific advice for bedrooms, living rooms and open plan.
Ceiling systems
Where ceiling-integrated purification makes sense, where it does not, and how it compares with floor and wall-mounted units.
Ceiling Air Purifier vs Floor Air Purifier: Which Is Better?
Footprint, airflow, noise, installation and service compared — including when a floor unit is the better choice.
Ceiling systemsCeiling-Mounted vs Wall-Mounted Air Purification
Air throw, the Coanda effect, structure, electrics and service height — the engineering behind each mount.
Air quality basics
What PM2.5, VOCs, CO₂ and common allergens are, where they come from and which control strategy fits each one.
Indoor Air Quality: PM2.5, VOCs and CO₂ Explained
Sources, WHO guideline values, sensor limits and the right control strategy for each pollutant.
Air quality basicsPollen, Dust Mites and Pet Dander: What an Air Purifier Can and Cannot Do
Particle sizes and settling times explain why purifiers help with some allergens more than others.
Buying & ownership
Checklists, noise, running costs and maintenance for the whole life of an air purifier.
Air Purifier Buying Guide: 12 Questions to Ask
Twelve questions, what a good answer looks like, red flags and a worked running-cost example.
Buying & ownershipAir Purifier Noise Explained: Decibels, Fan Speed and Sleep
dB(A), sound power vs pressure, fan laws and why a larger unit on a low setting is often quieter.
Buying & ownershipAir Purifier Maintenance Guide
A maintenance schedule table, safe filter changes, seal checks and a simple service log.