You're able to provide 17,000 kW for free? Nice.
17000 w/hour you mean? 17000 KW/hr is a lot.
You would need several big 240v 15-20A A/C to cool all of that, its not a good idea, just push the air strait outside. I hope thats in a warehouse because that would be a lot of noise.
But pushing the air outside will let air in. Air in will carry dust. Isn't that bad? What kind of extractor would i need? What size?
A very powerful one, and i don't know exactly depend how much space you got to let the air through. And yes, there will be dust, so what

? Use compressed air from time to time and buy box fan filters on ebay or such.
Dust don't really do much unless you let it accumulate by the inch. Unless you live in a very dirty environment or next to a volcano, you should be fine. Here i just blow some air through the heat sink every few months for good measure.
Never heard of an dust explosion, if dust gets too much and doesnt get cleaned, it heaps up. That is explosive and with the miners being hot, that is the ignition source and boom it blows up. Dust is dangerous!
I just honestly can't imagine somewhere with such dirty air. Even here in Québec we have relatively okay air and the dust does not accumulate overnight at all. It takes a year to have an accumulation that raise the temps by 7C~ for GPU and 2-3C for antminers.
And once a year, blowing compressed air through the heatsink is not really much maintenance imo, takes a few seconds per miner, which i only need to do at summer anyways because its cold 8 months a year here and then heat mean absolutely nothing, dust or not at this point.
If you live in a very dusty environment you'll need filters and lots of them i guess.
Anyhow. 17kW is not too bad on 240v. If its 120v that would be 141AMP~ which indeed sound too much for a "room". You'd need an industrial grade power circuit. Especially if you want to add some A/C during hot season.