Complete Guide to Indoor Air Quality (IAQ)
Understanding CADR (Clean Air Delivery Rate)
When buying an air purifier, marketing terms like "99.9% efficient" can be misleading. The only metric that matters is CADR. It measures the volume of filtered air delivered per hour. If your room is 20m², you need a purifier that can cycle all that air at least 2.5 times per hour (General use) or 5 times per hour (Allergies). Our calculator gives you the exact CADR number to look for on the box.
Why Humidify in Winter?
Cold air cannot hold moisture. When you heat cold air in winter, the Relative Humidity (RH) drops drastically, often below 20%. This dries out your mucous membranes (nose, throat), making you more susceptible to flu and colds. It also damages wooden furniture and floors. Using a humidifier to maintain 45-50% RH helps preserve health and home.
Ultrasonic vs. Evaporative Humidifiers
Ultrasonic (Cool Mist) machines are quiet but can spread "white dust" (minerals) if you use tap water. They require distilled water. Evaporative models use a fan and a wick filter. They are noisier but self-regulating (they can't over-humidify) and don't produce white dust. For bedrooms, evaporative is often safer.