Pigeons Cause Devastating Indoor Air Quality and HVAC Problems

Pigeon problems have devastating effects on the heating and cooling components and indoor air quality of a commercial facility.  Pigeon problems affect employees, maintenance personnel and potentially customers.

HVAC Systems Make Perfect Pigeon Coups

Unfortunately, rooftop heating and cooling units are a perfect place for pigeons to nest.  To seek shelter from the elements, pigeons typically enter air handler units through the fresh air intakes and build their nests within the HVAC unit.  A single pair of pigeons can generate up to 18 new pigeons per year.  Once a nest is established, pigeons are extremely territorial.

Indoor Air Quality

An HVAC system distributes the air throughout a facility.  The bacteria, fungi and parasites that live and grow in pigeon droppings can carry and transmit any of 60 known diseases.  Exposure to pigeon feces and other organic matter such as feathers carcasses and nesting material from the HVAC system may pose a considerable health threat to people who come in contact with them or inhale the airborne particles from them.  Every precaution should be taken to ensure that building occupants and maintenance personnel are protected from pigeon feces.

Damage to HVAC Systems

As pigeons live in the air handler units they peck through filter material allowing unfiltered air and pigeon contaminants to freely enter the ventilation system.  There are numerous damaging effects to an HVAC system.

  • Filter banks: Pigeons peck though filter banks allowing for unfiltered air and pigeon contaminants to be drawn into HVAC components and supply air ducts.
  • Fan Blower: Pigeon debris builds within the fan blades decreasing airflow.
  • Air conditioner coils: Pigeon debris compacts within air conditioner coils and clogs the drain pan.
  • Insulation: Pigeons peck at insulation to create nesting material allowing for raw fiberglass fibers to enter the airstream.

How Do You Correct Pigeon Problems?


Hire a professional wildlife service or animal control contractor to relocate existing pigeons, and install devices to prevent future intrusions.  Have the pigeon debris removed by a professional air duct cleaning contractor.  Be sure to have the air duct cleaning contractor inspect the supply air ducts downstream of the HVAC unit.