Get matched with top heating and air conditioning pros in Biddeford, ME

To keep your air conditioner in good working condition, you should have it serviced by a professional at least once per year, ideally in the spring before the cooling season begins. If your AC unit is 10 years or older, consider servicing it twice a year (once in the spring and once in the fall) to catch potential problems early and help it reach its full lifespan. During a service visit, a technician will inspect, clean, and replace parts as needed. Regular maintenance helps avoid costly repairs. As a DIY task, you can also clean the evaporator coils annually.

Window AC units use a fair amount of electricity, but significantly less than central AC systems. Because they are more energy-efficient for cooling individual rooms or small spaces, their usage is comparatively low. On average, a window AC unit consumes between 500 and 1,400 watts, while a central AC system uses over 3,500 watts—meaning a window unit uses about one-third of the energy. This typically translates to a monthly running cost of $15 to $40, although this can vary depending on external factors.

Deciding whether to replace just the AC coil or the entire system depends on the age of your unit and the overall cost. Replacing a coil is less expensive than a full system replacement, but it can still be a pricey repair. If your HVAC system is relatively new and still under warranty, or if the replacement cost is significantly lower than a new system, replacing the coil can be a worthwhile investment that restores efficiency and extends the unit's life. However, for older systems (nearing the end of their 10-15 year lifespan) or those with extensive damage, it is often more cost-effective to replace the entire AC unit. Mismatched coils in an older system can lead to inefficiency and future breakdowns, so a full replacement ensures optimal performance and avoids further costly repairs.

Most AC repair technicians will take between two and six hours to carry out repairs, depending on the work needed and the accessibility of the unit. For example, recharging refrigerant lines should take one to two hours to service, while replacing a compressor, blower fan, or other major components can take five to eight hours. You can ask your AC repair technician how long they expect the job to take, but just in case, you should plan on being home and available for most of the day.