When Preventative Maintenance Fails: Indoor Air Quality, and Mold Illness – My Review of Donovan Heating and Air 

In Northeast Florida, your air conditioning system is not a luxury. It is the central lung of your home, controlling temperature, filtering air, and managing humidity. In Jacksonville, where outdoor relative humidity routinely hovers above 80% to 90%, the line between clean air and an indoor mold bloom comes down to simple preventative maintenance.

As a functional medicine practitioner, I work daily with patients navigating environmental illness, Chronic Inflammatory Response Syndrome (CIRS), mast cell activation, and mold sensitivities. I understand what mycotoxins and airborne allergens do to human biology. Because of that, I have always stressed the importance of indoor air quality (IAQ) and whole-home dehumidification. For four years, I was a loyal customer of Donovan Heating & Air, frequently recommending their wellness division to my own patients who needed specialized care.

Recently, however, I discovered firsthand what happens when an HVAC company fails to perform the simplest, most fundamental tasks on a paid maintenance plan—and the steep health, emotional, and financial price that follows.

The Jacksonville Climate: Why HVAC Upkeep Is Medical-Grade Serious

Jacksonville’s climate creates an environment where moisture control is non-negotiable. When warm, humid air hits cold AC evaporator coils, condensation naturally forms. In a properly functioning and regularly serviced system:

• Condensate drains cleanly through unobstructed lines.

• Whole-house dehumidifiers pull ambient moisture down below the critical 50% threshold.

• Regularly swapped air filters trap particulates, dander, and fungal spores before they accumulate on damp internal components.

When any part of this chain breaks down, an air handler shifts from an air purifier to an incubator for microbial growth.For healthy individuals, this can trigger chronic sinus issues, fatigue, or brain fog. For mold-sensitive or immunocompromised patients, breathing mold spores and mycotoxins daily can be debilitating.

A Breakdown in the Basics: A Two-Year-Old Filter

After four years of paying Donovan Heating & Air for an ongoing service plan—with technician visits every six months—I began experiencing classic mold illness symptoms. Suspecting an environmental trigger, I ordered a urinary mycotoxin panel on myself. It came back positive.

Because we had previously invested thousands of dollars with Donovan to redo our ductwork and optimize our moisture control, I was shocked. We hired an independent mold inspector ($800) to inspect the house. Her findings were alarming:active mold growth was present right on the unit Donovan was scheduled to clean every six months.

When I went to inspect the system myself, the root cause became glaringly obvious: the main air filter had not been replaced since May 2024.

It was October 2026. For nearly two and a half years, service technicians had visited our property every six months,marked inspections as completed, and completely ignored the central air filter, proper coil cleaning, and our dedicated dehumidifier units.

Replacing an air filter is not advanced engineering. It is the single most basic, cost-effective preventative measure in the HVAC industry. Leaving an air filter in place for two years in Florida humidity creates massive static pressure, starves the system of airflow, and deposits dust directly onto moist interior surfaces—a recipe for system-wide mold contamination.

The Real Cost: Why Homeowners Shouldn’t Have to “Babysit”

When you pay a premium service contract to a reputable local company, you are paying for professional oversight and peace of mind. Homeowners should not have to crawl into their attics or look over the shoulders of licensed technicians to verify that a basic filter was changed or a drain pan was inspected.

The consequences of this failure extended far beyond an unfulfilled checklist:

1. Financial Strain: An $800 independent inspection, followed by paying Donovan another $3,000 to remediate and clean the ducts that had backed up with dust and microbial buildup, plus ongoing replacement costs.

2. Displacement: Because of acute systemic reactions, our household had to relocate to a hotel for two weeks while the home was remediated.

3. Health Impacts: Recovery from mycotoxin exposure is not instantaneous; clearing systemic mold illness takes months of dedicated detox protocols and clinical intervention.

What to Look for in a Jacksonville HVAC Maintenance Plan

If you or a family member deals with allergies, asthma, or mold sensitivity, you must protect your home’s ecosystem. Do not rely solely on reputation or verbal assurances:

1. Verify Filter Dates: Require technicians to initial and date the cardboard casing of your filters upon every replacement. Inspect it after they leave.

2. Audit Evaporator Coils & Drain Pans: Ensure your contract includes visual inspection and physical cleaning of the drain pan and coils, where standing water invites fungal colonies.

3. Dehumidifier Maintenance: Dehumidifiers possess their own dedicated washable or replaceable filters and drain lines; confirm they are explicitly serviced alongside the air handler.

4. Demand Photo Documentation: Reputable modern HVAC technicians take before-and-after digital photos of coils, clean filters, and condensate pans as part of their service report.

Parting Ways

It is deeply disappointing to part ways with a company I trusted and championed to patients for years. However, when basic maintenance is neglected to this degree, accountability is required.

I can no longer recommend Donovan Heating & Air, particularly to anyone dealing with chronic illness, mast cell disorders, or mold sensitivity. If you call Jacksonville home, treat your indoor air quality as a health priority—and make sure the technicians you trust to service it treat it with that same gravity.