From a yellow March morning to clean air: a Jacksonville filtration upgrade, step by step

Week one: the call

It is the first week of March. The oaks along the Avondale and Ortega streets have let go, every car is the same shade of yellow-green, and inside a 1930s house near the Cummer Museum the return grille has grown a gray fur in ten days. The homeowner’s child is wheezing. The call to Cook’s is short: the filter is new, the air still feels dirty, what are the options?

We ask four things on that call. What filter slot the air handler has (almost always a one-inch). Where the unit sits (closet, attic, garage). Whether anyone in the house has asthma or allergies. And the age of the ductwork, because filtration cannot fix what the duct brings in.

Week one, later: what changed in filtration

Three shifts matter for a Jacksonville buyer in 2026:

• Depth replaced density. The industry learned that a thick, pleated four- or five-inch media filter captures far more than a one-inch filter of the same rating, without strangling the blower. Deep cabinets are now the standard upgrade, not the premium one.
• Ratings got honest. MERV ratings are tested more consistently than they were a decade ago, and filters are labeled for what they actually catch: pollen at the lower ratings, fine smoke and bacteria-sized particles at the higher ones.
• Air cleaners went active. Electronic cleaners that charge particles, and purification systems that neutralize biological contaminants rather than merely trapping them, became ordinary residential products, mostly through lines such as Lennox Healthy Climate.

Blower motors also changed. Variable-speed motors can compensate for a better filter’s resistance; the old single-speed PSC motor in a 2005 Southside air handler cannot. That affects what we recommend.

Week two: what to buy for a pollen city

For the Avondale house, our usual recommendation ladder:

1. A media filter cabinet at the return, replacing the one-inch slot. This alone handles oak and pine pollen, dust and pet dander, and it is the step everyone should take.
2. An electronic air cleaner or HEPA bypass unit if someone in the house has asthma or allergies that a good media filter still does not settle. These catch the fine fraction that gets through pleats.
3. A coil UV lamp alongside either, because a Jacksonville coil is wet for eight months and a filter does nothing about what grows on it.
4. Duct sealing on any house with attic duct older than twenty years, before anything else, because filtered air that leaks out of the supply is wasted.

Week two: the install

A media cabinet install is an afternoon. The return plenum is cut and the cabinet set and sealed; if the return is undersized, which it is on most urban-core and 1960s ranch houses, we enlarge it so the blower does not starve. The blower speed is checked against the new static pressure. An electronic cleaner adds a power connection and a wash schedule. A HEPA bypass unit is a separate box with a small duct loop on the return. A UV lamp mounts at the coil and wires to run with the blower.

Book a filtration install

Week ten: May, and the first clean grille

By mid-May the pines have finished. The media filter comes out gray and heavy and goes in the trash; the new one goes in for the summer. The return grille is still white. The child is sleeping through the night. From here the routine is two media changes a year, a cell wash if there is an electronic cleaner, and a UV lamp check at the fall visit.

Cook’s installs the Lennox Healthy Climate filtration line and services the filtration equipment already in Jacksonville homes, from Fernandina Beach to the Westside. Ask which filter models are stocked for this market; the sizing and the return work are the same whichever one goes in. [[CONFIRM WITH JERRY]]