How would a tenant who leases part of a floor in a high rise building meter their use of chilled water from the base building plant? Each floor is served by one air handler, so this tenant uses part of the chilled water that goes to that floor's air handler.
Is it sufficient to meter total building chilled water (Btu or kWh of the plant) and prorate based on square footage? I don't see how it could be accurately measured otherwise.