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4.4
Environmental protection
The main environmental threats to a camera—particularly one that is installed outdoors—are
cold, heat, water and dust. Housings with built-in heaters and fans (blowers) can be used in
environments with low and high temperatures. In hot environments, cameras can be placed in
enclosures that have active cooling with a separate heat exchanger.
To withstand water and dust, housings (often with an IP66 rating) are carefully sealed. In situ-
ations where cameras may be exposed to acids, such as in the food industry, housings made of
stainless steel are required. Some specialized housings can be pressurized, submersible, bullet-
proofed or built for installation in potentially explosive locations. Special enclosures may also be
required for aesthetic considerations.
Other environmental elements include wind and traffic. To minimize vibrations, particularly on
pole-mounted camera installations, the housing should ideally be small and securely mounted.
The terms “indoor housing” and “outdoor housing” often refer to the level of environmental
protection. An indoor housing is mostly used to prevent the entry of dust and does not include
a heater and/or fan. The terms are misleading since the location, whether indoor or outdoor,
does not always correspond to the conditions at an installation site. A camera placed in a
freezer room, for example, will need an “outdoor housing” that has a heater.
The level of protection provided by enclosures, whether built-in or separate from a camera,
is often indicated by classifications set by such standards as IP, which stands for Ingress Protec-
tion (also sometimes known as International Protection) and applicable worldwide; NEMA
(National Electrical Manufacturers Association) in the U.S.; and IK ratings for external
mechanical impacts, which apply in Europe. When a camera is to be installed in a potentially
explosive environment, other standards—such as IECEx, which is a global certification, and ATEX,
a European certification—come into play.
More on IP ratings can be found here: www.axis.com/
products/cam_housing/ip66.htm
4.5
Vandal and tampering protection
In some surveillance applications, cameras are at risk of hostile and violent attacks. While a
camera or housing can never guarantee 100% protection from destructive behavior in every
situation, vandalism can be mitigated by considering various aspects: camera/housing design,
mounting, placement and use of intelligent video alarms.
4.5.1 Camera/housing design
Casings and related components that are made of metal provide better vandal protection than
ones made of plastic. The shape of the housing or camera is another factor. A housing or a tradi-
tional fixed camera that protrudes from a wall or ceiling is more vulnerable to attacks (e.g., kick-
CAMERA PROTECTION AND HOUSINGS - CHAPTER 4
