Oak pollen against a hallway filter grille in a 1970s Gainesville ranch
Where your filter lives says when your house was built. Where the pollen comes from says why the filter is failing by March.
Three houses, three filters
The 1970s ranch off NW 34th Street has a single return grille in the hallway ceiling with a one-inch filter behind it, and the owner needs a step stool and a flashlight to change it. The 1995 house in Blues Creek has its air handler in the garage with a filter slot at the cabinet, a little better, often a little neglected. The 2016 house in Oakmont has returns in several rooms and a filter rack at the handler in a closet. Student apartments near campus have a PTAC or a small horizontal unit with a washable screen nobody has washed.
Each was a reasonable design for its decade. None was designed for what Gainesville’s air carries.
The problem a filter solves here
From the last week of January the live oaks begin shedding, the pines join them, and the city sits under a yellow-green haze through March, with oak season running to May. A tree canopy covering nearly half the city adds mold spores from shaded, mossy roofs and damp attics all year. Rentals add pet dander and dust from high turnover. A filter’s first job is protecting the evaporator coil and blower from all of that; a coil matted with pollen loses airflow and freezes. Its second job is your sinuses.
A one-inch filter does the first job poorly and the second barely, and in a 1970s single-return house it does both while strangling a blower that was already pulling through too small an opening.
Filter tiers, plainly
- One-inch pleated. The baseline. Fine in a well-designed return, changed monthly in spring, more often during pollen peaks.
- Deep media cabinet, 4 to 5 inches. Far more surface area, so high filtration with low resistance and a change interval measured in months. The best upgrade for most Gainesville homes.
- HEPA bypass unit. Hospital-grade filtration on a portion of the airflow, for households with asthma or severe allergies.
- Electronic and carbon units. For fine particles and odors, with their own replacement schedules.
Lennox’s Healthy Climate filtration covers each tier, and the components mount on any brand’s air handler.
Installing the right one in the right house
In the 1970s ranch, the fix usually starts with the return itself: enlarging the hallway opening or adding a second return in the master bedroom so the blower stops gasping, then a media cabinet in the attic or at the handler. In the 1990s garage-handler house, a media cabinet bolts to the return side in an afternoon. In the tight 2010s house, filtration is simple and the real question is ventilation. In rentals, the honest answer is often a correctly sized one-inch return and a change schedule someone actually keeps.
Every install includes a static pressure reading before and after, because a filter that strangles the system trades a dusty house for a frozen coil.
Caring for it through a Gainesville year
Mark late January on the calendar; that is when the filter clock speeds up. Pleated filters get checked every two weeks through March. Media filters get checked at the spring maintenance visit and replaced when the pressure drop says so, not by the date on the box. Keep the return grille clear of furniture, and if the house is under heavy oak, expect to vacuum the grille face itself. Come summer the pace slows, until the air handler’s drain season arrives and a different page of this site applies.
Filter questions we hear from January to May
How often should a Gainesville filter be changed during pollen season?
Check a one-inch filter every two weeks from late January through March and expect to change it monthly or faster; the oaks keep going into May. A deep media filter stretches that to a few months, which is most of its appeal here.
Will a high-MERV filter hurt my 1990s Blues Creek system?
A dense one-inch filter can, because the blower was never sized for that resistance; the coil freezes and the motor strains. A deep media cabinet gets the same filtration with far less resistance. We measure static pressure before recommending either.
Can a filter stop the smell from the shaded, mossy side of my roof getting into the house?
The smell is usually spores and damp air entering through return leaks in the attic, not through the filter. Sealing the return and running the right media will reduce it; an ultraviolet lamp at the coil plus a dehumidifier handle what remains.
Do you set up filter deliveries for landlords with several Midtown units?
We can put filter changes on a maintenance agreement so the schedule does not depend on the tenant [[CONFIRM WITH JERRY]] on the agreement terms for multi-unit owners. No other step a Gainesville landlord takes does as much for the equipment.
Filters turning yellow every three weeks?
Call for a filtration setup matched to your return, your blower and your allergies.