HVAC systems on rooftops often are inviting locations for birds to roost. The heat and shelter they provide are a draw for birds. Also, pools of water often collect on the tops of flat-topped buildings, providing a convenient water source for the birds. As their droppings accumulate and dry out, this dust can get sucked into the HVAC system, spreading the disease-ridden dust throughout the entire building. This has caused people to get sick.
Ornithological research has found more than 60 transmittable bird-borne diseases and parasitic organisms that can lead to illness or death. When dried-out bird droppings are disturbed, a cloud of air-borne dust can carry microorganisms into the lungs, causing inhalation illnesses, such as histoplasmosis. Eating or drinking foods that have come into contact with bird-related bacteria also can cause ingestion sicknesses, including toxoplasmosis and query fever.
The current threat of avian flu means bird control may become more of an issue for building owners. So far, nearly all reported human cases of the illness have involved contact with infected birds--butchering chickens, eating undercooked poultry, or spending time in areas contaminated with bird blood or droppings.
For 26 years, Frank Sorentino has managed the outside structures and grounds of the Beaumont Hospital 106-acre (42-hectare) complex in Royal Oak, Mich. Bird control is an ongoing project for Sorentino and his crew.
A common mistake is to run one row along the outer edge of a building ledge, parapet or HVAC unit.
"The pigeons go to the air handlers--the HVAC vents on the rooftops," Sorentino says. "When dried bird droppings turn to dust and get sucked into the HVAC system, you're dealing with the potential for spreading diseases throughout the hospital. It's just not an acceptable risk."
The most effective and durable bird-control device for keeping birds and their droppings away from rooftop HVAC systems is stainless-steel "porcupine wire." These bird-control strips are relatively inexpensive and easily installed. A quality stainless-steel product can last practically forever.
Sorentino adds: "We've used Nixalite [of America, Inc., East Moline, Ill.] spikes around the HVAC ducts where there are particular concentrations of birds, and it's working well. We have a steady budget to add some Nixalite each year."
The device dates back to 1950 when the first "porcupine wire" was invented by Nixalite. Five years later, these newly invented, spike-covered mechanical barriers were installed on former President Dwight D. Eisenhower's farm near Gettysburg, Pa. According to the farm's maintenance supervisor, Ken Kime, the original installation still is in place and has successfully kept the birds away without any maintenance for more than 50 years.
Used for building ledges, parapets, roof ridges, gutters, signs, awnings, HVAC units, rafters or on most any surface where birds can land, bird spikes are constructed of stainless steel, plastic or a combination thereof.
The stainless-steel models cost a bit more, but their longevity evens out the expense over the product lifecycle. Plastic can become brittle when cold and soft when it is hot and eventually will deteriorate from direct exposure to sunlight.
Look for a deterrent that will repel birds of all shapes and sizes. Some advertised products only keep large birds away and are only for light infestation problems because they have large gaps between the wires and small birds may be able to sit or nest in between them. To avoid this situation, it is important to choose a product that has 120 wire points per foot with the spikes pointing in all directions.
When installing bird spikes products, make sure you follow the manufacturers' instructions very closely. Bird spikes will only protect the area that it covers. A common mistake is to run one row along the outer edge of a building ledge, parapet or HVAC unit. If you do not cover the entire surface, the birds will sit next to the spikes and may push nesting materials into the spikes.
The most effective bird-control device for keeping birds away from rooftop HVAC systems is stainless-steel porcupine wire.
Another important consideration when selecting bird spikes is the ease with which the product can be removed for cleaning, painting or other maintenance. For example, some porcupine wire strips use a mounting clip attached with fasteners or adhesives. The strips slide into the clip for secure installation but also can be easily removed without damage to the spikes or the surface; glue clips work great for metal roofs and HVAC surfaces that you may not want to penetrate with hardware. While many manufacturers suggest gluing the spikes directly to the surface requiring protection, Nixalite recommends using adhesive installations with a glue clip only when the surface cannot be penetrated with fasteners. Removing glued bird spikes can be very labor-intensive and can damage the product, the surface or both.
Whether it is new construction or a retrofit, successful bird control starts with a thorough cleaning of installation surfaces. Any location serving as a site for bird control must be disinfected, dried and cleared of debris to ensure not only a secure attachment but also a reduced chance of infection for workers. Cleaning can have another advantage in that it eliminates the scent trail--birds and animals are drawn to the scent of their own waste. Thoroughly cleaning and deodorizing installation surfaces eliminate this scent trail and discourages pests from following it back to their old roosts.
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