I understand the thermal output of these boards is quite low due to low power consumption, do you know what wattage is outputted as heat? And also if a single larger fan would be adaquate to cool several of the boards, I'd prefer them as a quiet and power cheap alternative to GPU mining.
100% of electrical power consumption is always equals to heat output (except some open systems like heatpumps). So if this board consumes 20W then 20W is released as heat.
Yes, I also asked ngzhang about custom cooling solutions. Hope his new product will contain holes for heatsink installation :)