The Air Conditioner

The air conditioner/heater unit I have is now a year old, and the company from which I purchased it provided a free one year check up. The technician showed me how to clean out the outdoor unit, and he checked for the temperature of the air coming out of the vents:  54° to 57°.  That explains why, when the air is blowing, I am too cold, although the thermostat is set at 78°.  But, that tells me the unit is working as it should.  I can also tell that by the electric and gas bills I have received this past year, and the actual usage of electricity and gas has been less, although I have the air conditioner set cooler (not much) and the heater set warmer (by about 3°) than I did before the new unit.