Time tariff is applicable to HVAC central air conditioning wherein a/c use is based on the operating time of the room blower fan.
Energy tariff is not suited for central or VRV air conditioning as the power consumption information is not readily accessible, so time tariff is the way to go for both.
In a classroom that uses either VRV or central air conditioning, electricity tariff is not applicable, so only time tariff can be applied
Can be used for various types of air conditioners including: central a/c, split-type a/c, window type, standing box type, and variable frequency a/c.
During classes, the instructor inserts the card to enable the a/c; after class, the card is removed and power is cut off.
Example: During the mornings, the classroom is for student use; in the evenings, the same classroom is rented to the community college.
Approach: The new rate is changed through the credit dispenser when the card is topped up; the administrator does not need to roam around to update each reader with the new rate.