The energy consumption of an air conditioner depends on various factors such as its efficiency, usage patterns, and the local climate. However, on average, a 1.5-ton (18,000 BTU) air conditioner can consume around 1.2 to 1.6 kilowatts (kW) per hour. So, if used continuously for an hour, it would consume approximately 1.2 to 1.6 units of electricity.