I have a 10x10 cage and two 42U cabinets in a NYC datacenter for an existing business. We are quickly migrating most of our applications to AWS, so there is a lot of empty space in the colo facility but our monthly cost is fixed.
Would it be worth it for me to get some mining hardware in there to offset the cost of the unused space? Also, would the existing power (multiple 110v PDUs per cabinet) be sufficient?
That really depends on your power cost. Being in a Tier-II or Tier-III colo in NYC I can't imagine the power is cheap.
OP said his costs were fixed.
It depends how long your contract is for and how much time you want to spend figuring how to mine. Then there is the the question of how risk tolerant you are.
The first thing you should probably do is go to Bitmain’s website. Using the specs for their S9, L3+ and D3 miners, plug the cost, speed and other info into their respective mining calculators to see if you will have the data center space long enough to earn back the cost of the miners. Right now I think the the order of profitability from high to low is D3, L3+, then S9 or T9. But that is also the order of instability (high to low) as far as profit margin volitility goes.
Make sense?
To give you an idea right now, 150 Th/s on an S9 SHA 256 miner gets you about $200/day.
1000 Mh/s (2x L3+) gets you about $40 - $60/Day.
But no matter what miners you choose, count on waiting for a batch to be released, then after you pay, it will be 1-2 months before they ship to you. Markets will change between purchase and delivery and as you are mining. So don’t expect to get as much profit as the calculations say you will. But as I said time is likely to be your biggest limiting factor.