Articles

By Jim Rosenthal, CAFS In the Fall of 2022, the EPA did chamber testing on DIY air cleaners to determine their effectiveness on reducing wildfire smoke. This resulted in an article in Indoor Air entitled “Impact of do-it-yourself air cleaner design on the reduction of simulated wildfire smoke in a controlled chamber environment” by Amara … More

The December issue of the ASHRAE Journal included an article entitled “How Do Particle Filters Work?” The article has graphs of “Efficiencies over time for two filters.” They come from ASHRAE Research Project (RP) 1190 — that was used to develop Loading Dust and Dust Loading Procedures for the ANSI/ASHRAE Filter Test Standards 52.1 and 52.2. The result … More

Tex-Air Filters has moved its headquarters, factory and Fort Worth warehouse to 5933 Eden Drive, Haltom City, Texas 76117. This 52,000 square foot facility was once the home of an aircraft parts manufacturer. It is a really good fit for our operation. It is very accessible for our customers (actually closer to downtown Fort Worth … More

Here is another version of the Mini Corsi-Rosenthal Box. It takes about 10 minutes to build. It has a small “footprint”. It is quiet – just 19 dBa. And the fans are rated at 104 cfm. Perfect for an office, bedroom, examining room or any other critical space where two or more people are in … More

The first Corsi-Rosenthal Box was built in August of 2020. It was presented as an “open source” concept so that as many people as possible could have low-cost cleaner, safer indoor air. It is based on sound engineering principles, but it is really very simple. Use 4 (or 5) MERV 13 filters in a “box” … More

By Jim Rosenthal In a previous article I summarized tests conducted using Corsi-Rosenthal Boxes with MERV 13 Filters at very high Air Change Rates. It was determined that two Corsi-Rosenthal Boxes could reduce particle counts in a small office to Class 10,000/ISO 7 levels in less than 15 minutes. Could Corsi-Rosenthal Boxes Reduce Particles to … More

By Jim Rosenthal As we have seen in numerous tests, Corsi-Rosenthal Boxes with MERV 13 filters have been shown to outperform HEPA Air Cleaners in particle removal – on all particle sizes. Given the difference in single pass efficiencies, this does not seem possible. After all, a HEPA is at least 99.97% efficient on all … More

In order to determine how air filters help to remove particles in a space, it is important to understand that filter effectiveness is not the same thing as filter efficiency. As it is currently defined, filter efficiency refers to the ability of a filter to capture particles in a single pass test. Filter effectiveness refers … More

By Jim Rosenthal Much of the Eastern United States is covered with wildfire smoke from the massive fires in Canada. A very effective way to avoid this respiratory hazard is to keep the windows closed and use an air cleaner – like a Corsi-Rosenthal Box. One word of caution – use the right filters. We … More

By JIm Rosenthal The most frequently asked question we receive on the Corsi-Rosenthal Box is: “When do you change the filters?” Of course – the answer is – it depends. There are a number of variables that need to be considered like – the quantity and type of particle exposure, the type of filters used, … More