The five biggest environmental threats to your security system are: lightning, water (in all forms), wind, temperature extremes, and dust.

Lightning

Lightning is one of nature’s most fatal yet instantaneous events. Cloud to ground lightning typically follows the path of least resistance, which is why it’s not a good idea to hide under a tree during a storm on a golf course: the tree’s height makes it a more likely target for lightning to enter the earth.

This same logic applies to cameras mounted on poles or high up on your building.  Not only is the camera itself a likely target, but any type of connected copper wire could be damaged by a strike. If using copper-based twisted pair wiring outdoors, conduit should be used for protection (or fibre optics is another choice – see June 2010 article on wiring beyond 100 metres). But whether you are using wireless connectivity, fibre optics, or plain old copper wire for Cat 5/6 twisted pair infrastructure, all wiring needs to be protected from power surges. Just like a fire break, you need a circuit that can be blown by the lightning strike and block the voltage path from entering your building. 

Another best practice dictates using proper grounding to give the lightning a separate, safe path to travel to its end-point in the earth. In particularly lightning-prone areas you could use lightning suppressors, which can be found at most electronics outlets and distributors.

Water

2011 has been the year of the flood thus far with record levels occurring in many areas of Canada and the U.S. But while total protection against a major flood is neither realistic nor cost-effective, you can still protect yourself from common water problems such as rain, snow, and ice.

Using a proper IP-rated enclosure will protect your camera from wind driven rain and keep out snow (see chart). An IP66-rating will protect you against a powerful water spray, while a rating higher than IP66 protects the enclosure from water immersion – although there are very few surveillance installations that call for underwater cameras. Like lightning, water will always find the path of least resistance, so even the smallest opening in your camera is at risk. This is why it is so important to install the rubber grommet that comes with most outdoor cameras to seal the opening where the Ethernet wire enters the camera housing.

In the winter, ice storms can wreak havoc with your enclosure’s temperature rating on the lower end.  Even though ice storms at -10°C and below are extremely rare, when the temperature drops suddenly and the moisture on the cover rapidly freezes, your camera will be effectively blinded. Your -40°C-rated enclosure may only be warm enough at -10°C to actually melt the ice. If you are in an area where ice storms occur at very low temperatures or where rapid temperature drops are commonplace, make sure to verify the specific rating for your enclosure in these situations.