HouseFresh

AI is killing All About Berlin. When you Google something, you used to get a link to my website, but now you get an AI-generated answer trained on my work. This has a devastating impact on traffic.

AI is killing All About Berlin. When you Google something, you used to get a link to my website, but now you get an AI-generated answer trained on my work. This has a devastating impact on traffic.

Recently, I've received several emails requesting H13 or even higher-grade filters. I would still like to explain here why H13 and higher-grade filters are not a good choice for air purifiers. A good air purifier's primary goal is to clean the air in a room as quickly as possible. There is a specific metric to describe this: CADR (Clean Air Delivery Rate). The higher the CADR, the faster the purifier captures airborne particles on the filter. Achieving a high CADR requires two conditions: High filtration efficiency – the filter should capture a high percentage of particles that pass through it. Large airflow volume – a large amount of air should flow through the filter per unit of time. If the airflow is large but the filtration efficiency is low, only a few particles are captured each pass. Conversely, if the efficiency is high but the airflow is small, the total number of captured particles is also low. But these two factors contradict each other. With the same fan, using a higher-grade filter improves efficiency, but it also increases resistance, which reduces the airflow. So a higher-grade filter is not always better. Filters like H13 or H14 commonly found on the market have very high resistance, significantly reducing airflow and thereby lowering CADR — meaning slower purification. After extensive testing, I found that the E11 filter offers the best balance. With about 95% filtration efficiency, its airflow loss is minimal, resulting in the highest overall CADR and thus the fastest cleaning speed.