Inverter ACs cost more upfront but cut the electricity bill sharply, which is exactly why buying one used makes so much sense. These ads cover second hand inverter air conditioners in Karachi, mostly 1 ton and 1.5 ton units from Haier, Gree, Dawlance and Orient. Ask for the purchase date and whether the compressor warranty is still valid, since that is what separates a good deal from a risky one. For other types see Air Conditioners.