UV germicidal lights are one of the simplest and most effective indoor air quality upgrades for a Pittsburgh home. They mount inside your HVAC system, point at either your evaporator coil or your airstream, and use ultraviolet C-band light to kill mold, bacteria, and biofilm wherever the light reaches. They run quietly, use very little electricity, and dramatically reduce the biological growth that builds up on a cooling coil and inside ductwork over a Pittsburgh summer.

If you have ever noticed your AC smelling musty when it first kicks on in the spring, that is biofilm on the coil. A UV light prevents it.

What UV germicidal lights do

UV-C (ultraviolet, C-band) light at the right wavelength damages the DNA and cell walls of microorganisms, which prevents them from reproducing. For an HVAC system, that means:

• Stops mold growth on the evaporator coil. Your cooling coil is cold, wet, and dark, the three things mold loves. A UV light keeps it sterile.
• Reduces biofilm in the drain pan and ductwork. The slimy buildup that develops over time in a humid HVAC environment.
• Kills airborne pathogens that pass through the beam. Bacteria, viruses, and mold spores moving through the air stream get reduced as they pass the UV bulb.
• Eliminates musty AC smell. That damp-towel smell when the AC first runs in the spring is biological. UV stops it from forming.

Two types of UV lights we install

There are two ways to use UV in an HVAC system, and they do different jobs. Most homes pick one. Larger homes or high-end IAQ packages get both.

Coil-mounted (stick light)

A UV bulb is mounted near the evaporator coil, where it shines on the coil 24/7. This is the most common setup. It is what we recommend for almost every Pittsburgh home upgrading their IAQ.

• Targets the dirtiest, dampest part of your HVAC system.
• Runs continuously, even when the blower is off, because mold grows when the blower is off.
• Maintains coil cleanliness year over year. Many customers see noticeably better airflow and efficiency a season after installing one.
• Replacement bulb every one to two years, depending on the bulb type.

Airstream (in-duct) UV

A UV bulb (or array of bulbs) mounts inside your duct so air passes through the beam. Used for treating air as it moves through the system, not just the coil.

• Adds airborne pathogen reduction on top of coil treatment.
• Typically larger, with higher UV output, to get enough exposure during fast-moving air.
• Often combined with REME HALO or iWave for full-spectrum air treatment.
• Replacement bulb every one to two years.

For most Pittsburgh homes, a coil-mounted UV light plus an Aprilaire media filter plus either REME HALO or iWave is the full IAQ package. We recommend in-duct UV when the home has a specific airborne pathogen concern, immune-compromised occupants, or larger square footage that needs more aggressive treatment.

Why UV makes sense for Pittsburgh

Hot, humid summers. Pittsburgh summer humidity drives heavy condensate on the cooling coil. Without UV, that wet coil is a perfect home for mold. With UV, it stays sterile.

Older basements where AC equipment lives. Many Pittsburgh basements are damp through the cooling season. The air handler or furnace sits in that environment. UV protects the cooling coil from the biological load in basement air.

Long heating season. Your blower runs a lot from October to April. A coil light keeps things clean year-round, not just in summer.

Older ductwork. Older Pittsburgh ductwork sometimes carries decades of buildup. UV reduces the biological component of that buildup over time.

How a UV light installs

About a 1 to 2 hour install for a coil-mounted light, slightly longer for in-duct.

1. Locate the right position. For coil lights, we mount near the evaporator coil where the bulb shines directly on the coil surface. For in-duct, we pick a section of duct with good access and proper distance from any sensors.
2. Cut and mount. Clean rectangular cut, mount the fixture with self-tapping screws, seal the perimeter.
3. Wire it. 24V from your furnace or 120V depending on the model. We bring it in through a junction box on a continuous circuit so the light stays on.
4. Verify. Check the bulb is lit, the wiring is secure, and there is no UV leakage outside the unit (UV-C is harmful to skin and eyes, so the fixture must contain it).
5. Show you the unit and the indicator.

Maintenance

• Bulb replacement every 1 to 2 years. Even if the bulb is still glowing, UV output degrades over time. After 1 to 2 years it has lost enough power to be ineffective even though the bulb still works.
• Annual check during HVAC maintenance. Your Wahl Club membership includes a UV check during your AC tune-up. We make sure the bulb is working and at proper output.
• Replacement bulbs available through Wahl. We can deliver, install, or both.

Pricing

Flat-rate install pricing on every quote. Member and standard rates shown side by side. Financing through GoodLeap, Synchrony, Wells Fargo, and EasyPay.