Why air conditioners in Los Angeles get dirty
An air conditioner moves a lot of air. In much of Los Angeles, especially inland neighborhoods and the valleys, central air can run from late spring well into fall, and heat waves can stretch into October. All that run time pulls dust, pet hair and lint toward the indoor coil while the outdoor unit sits in the open, collecting leaves, blown dirt and debris from Santa Ana wind events. Smoke and ash from wildfires, like the January 2025 Palisades and Eaton fires, settle on outdoor equipment too.
The U.S. Department of Energy notes that outdoor condenser coils can become very dirty if the outdoor environment is dusty or if there is foliage nearby, and it recommends checking the evaporator coil every year and cleaning it as necessary. AC cleaning is how that cleaning gets done without anyone touching the refrigerant side of your system.
The indoor evaporator coil
The evaporator coil is the cold part of the system. It sits next to the furnace or air handler, usually inside a sealed cabinet, and warm house air passes over its fins to be cooled. Because the coil is wet during operation, dust that reaches it tends to stick and build up into a mat.
A clean, well-fitting filter is the main defense, but some dust always gets through, especially when filters are skipped or the wrong size. We clean the coil surface we can reach through existing access panels, using methods that suit the coil and do not bend the fins. We do not cut refrigerant lines, remove the coil or open sealed refrigerant components; that is HVAC technician work. If your coil is buried behind sealed panels, we will tell you what we can and cannot reach before we start.
The outdoor condenser coil
The outdoor unit gets rid of the heat your AC pulls out of the house. Its coil wraps around the cabinet with fine aluminum fins that can clog with leaves, seed pods, grass clippings and dirt. A blocked condenser coil has to work against that layer every time it runs.
With the power shut off at the disconnect, we clear debris from around and inside the cabinet where it is accessible, clean the coil and rinse it at low pressure from the appropriate direction so the dirt comes out instead of being pushed deeper. High-pressure spray can flatten fins, so we avoid it. We also look at what is around the unit. The Department of Energy recommends keeping foliage trimmed back at least 2 feet from the outdoor unit so air can flow freely, and in Los Angeles yards that often means bougainvillea, hedges, side-yard storage or a fence built too close.
The drain pan and condensate line
As the evaporator coil cools the air, it also pulls moisture out of it. That water collects in a drain pan and leaves through a condensate line, which usually runs outside or to a drain. Over a long cooling season, dust, sludge and algae can slow or block the line.
The Department of Energy notes that clogged drain channels prevent a unit from reducing humidity and that the excess moisture can discolor walls or carpet. In attic installations, which are common in Los Angeles homes where central air was added later, a backed-up drain can drip into the ceiling below. We clean the drain pan and clear the condensate line, then confirm it carries water away once the system is running. If the pan is rusted through or the line is improperly sloped, we will point it out so you can have it repaired.
Filters: the part you control
Filters are the simplest way to keep coils clean between visits. The Department of Energy recommends cleaning or replacing your air conditioning filter every month or two during the cooling season, and more often if the system runs constantly, if you have pets, or if the home is dusty. It also states that replacing a dirty, clogged filter with a clean one can lower an air conditioner’s energy consumption by 5% to 15%.
During every AC cleaning we check your filter’s size and fit and how it sits in the rack. A filter that leaves gaps lets air bypass it entirely, which sends dust straight to the coil. We will tell you what size to buy and how often to check it given how your household uses the system.
Homes, condos and commercial spaces
Many central air systems in Los Angeles homes are split systems: an indoor coil on top of or beside a furnace or air handler, and a condenser outside in a side yard, on a slab behind the garage or on the roof. Hillside homes and condos may have the outdoor unit on a balcony, a rooftop or a narrow ledge, which affects how we reach it. Small offices and shops often use rooftop package units that house both coils in one cabinet. The cleaning principles are the same in every case, but access is different, so we look at the setup first and tell you what we can safely reach before quoting.
What AC cleaning does not include
WINN AIR CORP cleans air conditioning components. We do not repair, recharge, install or replace air conditioners. That means no refrigerant work, no electrical diagnosis, no capacitor or contactor replacement, no compressor or fan motor repair, and no system sizing or installation. If your AC is not cooling, is short cycling, has ice on the lines or is making new noises, you need a licensed HVAC technician. We will tell you what we noticed while cleaning so you can pass it along.
How AC cleaning fits with other services
AC cleaning focuses on the coils and drainage. If dust is also caked on the blower wheel or inside the return plenum, HVAC cleaning covers those parts, and many customers combine the two in one visit. If dust is coming out of your vents or the ducts have not been cleaned in years, see air duct cleaning. To see if we cover your neighborhood, check our service areas, and read air duct cleaning vs. HVAC maintenance to understand where cleaning ends and a tune-up begins.
Schedule AC cleaning in Los Angeles
Before the next heat wave, call WINN AIR CORP at (213) 596-9955 or request a free estimate. We will look at your indoor coil, drain line and outdoor unit and give you a clear price before any cleaning begins.