Who pays the chiller / cooling charges - me or the landlord?

It depends on the system. In 'chiller-free' buildings the landlord pays cooling (it runs off the building supply). With district cooling (Empower, Emicool), tenants usually pay the consumption charge; the fixed capacity/demand charge may fall on landlord or tenant depending on your contract addendum. Electricity and water (DEWA) are always the tenant's. If the contract is silent, disputes go to the RDSC.