This is a "scratch" page used to record various measurements and test results obtained for the Corsi-Rosenthal Cube.

Room sizing / CADR figure

CFM measurements of a 4-sized cube configuration were taken here:

As per conversation with David Elfstrom, these figures were using a Lasko Power Plus fan, which puts out ~20% more flow than typical fan.

In David Elfstrom's own CADR predictions, he uses a figure of \(\sim62\%\) efficacy of the MERV-13 filters (confirmed with him). So this is a figure based on \(0.3um\) particles expected lower bound performance with the MERV-13 filters.

COVID-carrying particles are likely larger than 0.3um (most penetrating particle size), so this is a lower bound figure. I am not sure if the exact size distribution of COVID-carrying particles is known. We know \(80\%\) of them are are "less than \(5um\)."

Using John Semmelhack's CFM measurements, we can make a guess at the difference between the cube with 1" filters and the cube with 2" filters. His cube was constructed with 2" MERV-13 filters.

We assume a conservative figure here. Want to give a lower bound. So this scale multiple looks like \((349/455)\).

\((349/455)*871*0.62*0.80 = 331 \text{ CFM CADR}\).

Fan shroud added

As per David Elfstrom's measurements, an optimally-sized fan shroud increases the fan flow by \(47\%\). We should assume that not everyone gets the exact optimal fan shroud sizing (due to differences in fan models), so let's lower this by \(20\%\) to \(37.6\%\):

\(331 * 1.376 = 455 \text{ CFM CADR}\)