From the first yellow dust to the first 90-degree day: a six-week pollen calendar for your air conditioner

The season, in order

Columbia County is pine country with live oaks in every yard, and both trees bloom before spring arrives. The slash and loblolly pines release their pollen first, from late January into February: the yellow dust that coats cars, porches and the top of every outdoor unit. The live oaks follow in late February and March with catkins, the brown tassels that pile in gutters and against the condenser’s fins. By mid-March both are at full strength. By early April the rains knock the last of it down, just as the first 90-degree afternoon arrives and the air conditioner goes to work for real.

Six weeks, two trees, one piece of equipment that has to breathe through all of it. Here is the calendar.

Week one: the first yellow dust, late January

The pines start. Overnight the windshield is yellow and so is the top grille of the outdoor unit. The system is mostly in heating mode, which means the outdoor coil is pulling air across itself all night and collecting pollen the whole time.

Do this week: Change the filter even if it looks fine; the season is about to load it. Look at the outdoor unit and note how clear the fins are now, because that is the baseline. Clear leaves and debris from around the base so air can reach the sides.

Week two: the pines in full, early February

The dust is everywhere. Filters that normally last two or three months are visibly gray within two weeks. The outdoor coil has a yellow film that is still loose and easy to rinse.

Do this week: Rinse the outdoor coil with a garden hose, power off at the disconnect first, spraying from the inside out if the top comes off easily or gently from outside if not, top to bottom. Do not use a pressure washer. Check the filter again; replace if gray.

Week three: the oaks begin, mid-to-late February

Catkins start to fall and the brown tassels collect on top of the condenser, in the fan guard and against the fins, where they hold the pine dust in place like a mat. The heating season is winding down and there may be a few warm afternoons when the system cools; this is the first time the indoor coil sees pollen-laden air moving fast.

Do this week: Pull catkins off the top of the unit by hand. Change the filter if it is loaded; in a yard with big oaks, this is likely a two-week filter now. Check that the supply registers are not blowing dust, which would mean the filter has been bypassed or the duct is leaking on the return side.

Week four: everything at once, early March

Peak. Pine and oak together, dry windy days, yellow-brown dust on every surface. This is the week the filter photographs on this page were taken. Systems with original attic duct pull pollen in through return leaks the filter never sees. Allergy sufferers notice the house is worse than the yard.

Do this week: Filter again. Second coil rinse of the season. If anyone in the house is suffering, this is the week to talk about a media filter cabinet, which gives a higher-rated filter the surface area it needs without choking the blower, and about sealing the return duct.

Call 866-266-5709

Week five: the first warm stretch, mid-March

The first run of 80-degree afternoons. The system is now cooling for hours a day, and a coil that was not rinsed is paying for it: head pressure is high, cooling is weak, and the electric bill for March arrives higher than February’s even though the weather was mild. A loaded filter starves the indoor coil of airflow, and on a humid afternoon an airflow-starved coil can freeze.

Do this week: Make sure both coils are clean. If the system seems weak or the lines frost, shut it off and call rather than running it frozen. This is the natural week for a spring maintenance visit: coil cleaning done properly, capacitor and refrigerant checked, drain line flushed before the wet season.

Week six: the rains and the first 90, late March into early April

Spring storms wash the last pollen out of the air and off the unit. The first 90-degree day usually lands within a couple of weeks of it. The season is over; what remains is whatever got into the system during it.

Do this week: Final coil rinse to clear what the rain pushed deeper into the fins. Fresh filter for the start of summer. Date it with a marker so you know when it went in.

The filter, in one table

Filter	Catches pollen?	Airflow cost	Where it fits
Fiberglass, low rating	Poorly	None	Protects the coil from large debris only; change monthly
Pleated, middle rating	Well	Modest	The right answer for most Lake City homes; two to four weeks in pollen season
Pleated, high rating	Very well	Significant	Only where the system was designed for it; otherwise it starves airflow
Media cabinet, high rating	Very well	Low, thanks to surface area	The upgrade for allergy households and heavy-oak yards
Washable electrostatic	Variable	Rises as it loads	Needs washing every two weeks in pollen season to work at all

What a spring visit catches that a homeowner cannot

The coil rinse and the filter are homeowner work. A spring maintenance visit goes further: the indoor coil inspected and cleaned where pollen got past the filter, the blower wheel checked for buildup, the refrigerant charge verified before the hot months, the capacitor tested, the condensate drain flushed and the float switch tested before the June rains. In a yard with pines and oaks, that visit scheduled for late March is the one that keeps July uneventful.

Pollen season from Palm Coast

Cook’s serves Lake City and Columbia County from its headquarters at 37 Fairmont Ln in Palm Coast, about two hours and twenty-five minutes away, running spring maintenance by neighborhood from late February through April. Maintenance agreements put households on the schedule before the season starts; ask for the agreement tiers when you book. [[CONFIRM WITH JERRY]] Phone answered any hour, no after-hours charge, Lennox installed, every brand repaired and rinsed.