Downside is it could be a bunch of A1 miners. Which are not really that efficient of miners.
OP ask what miner it is your getting. But I'm betting a bunch of A1's. Which if free ore cheap electricity is fine. Just not good longterm for normal electricity.
is electricity is free, so efficiency will not matter
i would do it without thinking, basically free money, but i may find a bit fishy to be honest, i would check everything twice prior buying
Free electricity is tricky as if included in rent chance are they do not mean for miners to use it. And most places with it are limited on amount of electricity they have.
But OP said:
Chances are the owner of building has a provision and if your mining 1/2 or all of rent in electricity.... i bet you get kicked out the following month. It would have to be a big corporation to take a hit like that and hold up on free electricity. Most landlords would not take a hit like that on electricity.