HVAC technician installing UV-C bulb in air conditioning unit

Where to Install Your BioShield Classic & Magnetic Bulb

Note: Professional Installation Required – This guide shows you where your bulbs should go but installation must be done by a licensed HVAC professional.

You Have Your BioShield - Now What?

Your BioShield needs to go in your return air plenum – that's the big rectangular chamber where air enters your HVAC system, usually located near your air handler or furnace.

Why there? Air moves slowly (perfect for UV treatment) and it's cooler (UV bulbs work best in cool air).

BioShield Classic UV-C bulb system

If You Have BioShield Classic

  • What you'll do: Drill holes through the plenum wall using your included template
  • Where bulbs go: Through those holes, positioned perpendicular to airflow
  • Distance from coil: 2-4 feet away for optimal coverage
BioShield Magnetic UV-C bulb system

If You Have BioShield Magnetic

  • What you'll do: Attach the magnetic base to any metal surface in the plenum
  • Positioning: About 2-4 feet from your coil, can be adjusted after installation
  • Where it sticks: Metal wall on the return air side

Step-by-Step: Where to Install Your BioShield

01

Locate Your Return Air Plenum

Return air plenum - large rectangular metal box in HVAC system

What you're looking for: The large rectangular metal box where air enters your HVAC system

  • Usually near your furnace or air handler
  • Has your air filter nearby (often on the front)
  • Air gets sucked INTO this box, not blown out of it

Can't find it? Contact Technical Support – describe your system type and we'll walk through it with you.

02

Find the Installation Spot

BioShield Classic UV-C bulb system

If You Have BioShield Classic

  • Look for the metal wall of your return air plenum
  • Measure 2-4 feet from your evaporator coil (the big metal fins)
  • Use your included template to mark where holes will be drilled
  • Position perpendicular to airflow (bulbs go across the air path, not with it)
BioShield Magnetic UV-C bulb system

If You Have BioShield Magnetic

  • Find a metal surface inside the return air plenum or air handler
  • Position 2-4 feet from the evaporator coil
  • Test the magnetic hold – it should stick firmly to the metal surface
  • Make sure power cord can reach either a wall outlet or HVAC connection
03

Alternative Locations (If Return Air Won't Work)

Inside of air handler cabinet showing installation location

Option 2: Inside Your Air Handler Cabinet

  • What it is: The main HVAC unit box itself
  • Where to install: On the interior wall, return air side of the blower
  • Classic: Drill holes in cabinet wall, secure bracket
  • Magnetic: Attach to metal interior surface, away from blower motor (6+ inches)

Can't decide what alternative position works for you? Contact Technical Support

What to Avoid ( Don't Install Here)

Supply side ducts where air blows out of HVAC system

Supply side ducts (Air blows OUT of your system)

Air moves too fast and runs too hot for effective UV treatment.

Evaporator coil too close for UV-C bulb installation

Too close to your coil (under 18 inches away)

UV light at close range degrades coil fins over time.

Branch ducts leading to individual rooms

Branch ducts (individual room ducts)

Only treats air going to one room instead of the whole system.

Furnace heat exchanger area to avoid for installation

Near your furnace heat exchanger

Excess heat shortens bulb life significantly.

Special Offer

Both models are eligible for:

  • Automatic bulb delivery every 10 months
  • 15% bulb replacement discount
  • Lifetime warranty on HVAC unit hardware
  • Priority technical support for placement optimization
Special offer discount illustration Learn More About The Guardian Club

When to Call BioShieldUV Technical Support

Fill out our Contact Form for any query.

Placement Questions We Can Answer: Professional Assessment Required: ✓ Model selection based on square footage ✗ Specific installation location decisions ✓ Power requirements and compatibility ✗ HVAC system modifications ✓ General placement principles and guidelines ✗ Electrical troubleshooting and connections ✓ Bulb replacement schedules and ordering ✗ Local code compliance verification

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