I haven't had any more or fewer problems with contamination, but I have seen greatly improved yields after adjusting the fan. After the spawn run the substrates are very resistant to contamination, and the air in the chamber is full of bacteria and fungal spores no matter which way the fan is situated. You're all good :)
Even during the spawn run, if you pasteurize well, there is very little chance of contamination, unless of course you introduce the contam with the spawn already germinated and healthy... I often harvest bare handed and have seen no increase in contamination... I often toss them well before contamination is a concern... I rarely see a contam in my three flushes.
This is a very cool box by the way... Similar and in some ways superior to the ones I was constructing 8-9 years ago...
Edited by PJammer24, 30 October 2019 - 11:11 AM.