While about two out of every three homes in America do have air conditioning, there is still some confusion about proper maintenance and upkeep of AC services. Typically, an HVAC company should be onsite about once a year to monitor home cooling systems, and filters should be changed at least three times every year. Contractors should be able to demonstrate the proper technique for changing air filters; homeowners who keep track of their heating and cooling expenditures should notice a reduction in their annual costs after consistent filter replacement. Sometimes, an increase in a home’s levels of dust is noticeable…