Getting a system through a Memphis summer

Air conditioning here works harder than in most of the country, and it does it in humidity. The two most common failures in a Memphis summer are both preventable from the ground.

Filters. Change them every one to three months, and at the short end of that if you have pets or anyone in the house with allergies. A blocked filter starves the system for air, which makes it run longer, cost more, and in the worst case freeze the coil solid. Write the date on the edge of the filter in marker — it settles the argument about when you last changed it.

The condensate drain. Air conditioning pulls a remarkable amount of water out of humid air, and that water leaves through a drain line. In a humid climate, algae and slime block those lines routinely, and when the line backs up the water finds somewhere else to go — usually a ceiling. Once a year, before cooling season, flush the line with a cup of distilled vinegar. If your system has a float switch that shuts it down when the pan fills, that is a feature, not a fault; it just saved your drywall.

Outside, keep two feet clear around the condenser. Trim back shrubs, pull the leaves out of the fins, and do not build a deck box around it.

Twice a year — before cooling and before heating — is the sensible rhythm for a professional service visit. The spring one is the one that matters most here.

Call someone if: the system is not cooling despite a clean filter, you see ice on the lines, anything involves refrigerant or electrical connections, or you smell anything burning.