Replace The Unit Cover, & Turn It On To Make Sure It Runs Properly

The air conditioner filter should also be replaced every few months. It is usually located near the return air duct by the furnace. Since prehistoric times, snow and ice were used for cooling.

The business of harvesting ice during winter and storing for use in summer became popular towards the late 17th century. This practice was replaced by mechanical ice-making machines.

The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water.

The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate.

In Ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season.

Dichlorodifluoromethane (R-12) was the most common blend used in automobiles in the US until 1994, when most designs changed to R-134A due to the ozone-depleting potential of R-12. R-11 and R-12 are no longer manufactured in the US for this type of application, so the only source for air-conditioning repair purposes is the cleaned and purified gas recovered from other air conditioner systems.