I was going to take the boards out of the metal case.  There is a warranty sticker on one of the screws on both the front and back of the box that holds the boards inside.  I can remove the fans though with no problem.

I was going to remove the boards, blow compressed air across the heat sinks and scrub the heat sinks if need be.

I'm still working on getting a workable filter for my room.....in the meantime I have been running several Antminer S9/L3 with supply fans that have no filter for about 5 weeks.  There is a visible thin layer of dust on top of the PSU and miners.  The exhaust fan has fine dust on the blades.  You get the picture.

Intake airflow exceeds total intake of all miners combined.  Exhaust fans also exceed total exhaust of all miners combined.

Chip/board temperatures are consistent and predictable.  The S9s run less than 80 C unless the ambient temperature is above 70 F (working on some exhaust issues).

HERE ARE THE QUESTIONS....

1.  Do I break the warranty and airblow with compressor (with moisture trap) all the miners since there is visible dust on the equipment and then install a workable filter....

OR

wait until the warranty expires then clean them ?

2.  How will dust related problems manifest ?  Will the temperatures start to get higher and higher despite adequate cooling measures or will the board suddenly either die or stop working until cleaned ?

I'm leasing a garage apartment about 350 sq ft which has windows on two adjoining walls.  The miners will be on a wire rack shelf with a "hot box" behind it and that will have a fan to pull that hot air to the outside through the attic.

I plan to have 40 miners and am looking at intake fans to bring in at least 10,000 cfm of fresh air.  So a few random questions...

1.  What type of fan ?  Do you take an "exhaust fan" that looks like it's a "box fan" ?  If so, do you just turn it around so that it functions as an intake or can you reverse the blade direction ?  It just seems awkward to have the motor exposed to the outside pointing towards the inside.

2.  Is there a way to match a filter with a fan ?  I'd like to get some basic filter in place but don't see a way to attach a filter and am not sure how that would fit together.

3.  How do you prevent rain water from being blown into the room ?  I imagine a 10,000 CFM fan blowing hard during a rainy day and the normally vertical falling raindrops get sucked into the fan and blown into the room.  Any suggestions on how to prevent this ?

Thanks.

Any update on the OP cooling/vent issue ? 

I've been also researching the cooling requirements and airflow management for my soon to arrive Antminers.  I've run across a resource that may be helpful.  It's from APC Electric which is, according to their website, the "industry-standard for reliable power and physical IT infrastructure."  

It's a whitepaper on calculating the total cooling requirements for a data center.

http://www.apc.com/us/en/support/resources-tools/white-papers/calculating-total-cooling-requirements-for-data-centers.jsp

The other resource is from a company called Upsite Technologies which is all about optimizing data center cooling.

https://youtu.be/sWinOiYqPSE

You are effectively building a very small data center and you don't have to reinvent the wheel to implement best practices to your own "mini-center".  Obviously you won't spend the kind of money big companies do but you can still take the principles of efficient energy use, airflow management and cooling techniques and creatively fit them to your needs.  Good luck and keep us posted !