Security Smoke Systems have been employed to defend high risk property and premises as far back as 1974, yet they are often the last system considered, or even heard of. The idea behind them is a simple one.......
Remove a burglar's ability to see, and he will find his task at best a lot more difficult, at worst (and in 99% of cases), impossible....
The simplest way of removing the ability to see? Flood a protected area with an obscuring smoke!
The idea did not really find much demand (other than extreme high risk premises) until around 20 years ago,
It became apparent that for a lot of premises, "conventional" measures were no longer enough:
- Physical security (bars and grilles) tends to raise the level of violence employed to gain access to the building. Thieves employ angle grinders, skill saws, Land Rovers, anything to gain fast access to their targets. This obviously raises the capital loss suffered by the victim.
- Intruder alarms are ignored by this style of criminal as the average break-in is finished and the perpetrators fled with their spoils within three minutes. It is a challenge for the police or key holders to respond in this timescale and the thieves know it.
- In most cases thieves mask their features as they are aware of the presence of CCTV and recording equipment.
Many insurers and commercial outfits as well as a growing number of domestic residences have now turned to Security Smoke as a pro-active means of protecting stock and deterring professional burglars and thieves.
To date in the UK alone, there are well over 100,000 premises using this defence measure.
What is Security Smoke? How does it work?
The term smoke is often misleading as it conjures images of heat, fire and damage. A more correct term could be thermally generated fog.
There are several manufacturers of Security Smoke generators and while every generator on the market has differences, the way in which they produce fog remains fairly similar.
- A specially formulated solution containing a chemical from the glycol family is passed over a high temperature heat source and heated above its boiling range.
- The solution forms a vapour which cools very rapidly when it is introduced to the outside air. The vapour condenses and forms a fog - millions of microscopic liquid particles suspended in the air.
- The very dense white appearance of the fog is caused by light refracting through the particles and bouncing back into your eyes.
- Because the particles produced are so small (varies from manufacturer to manufacturer, but range from an average diameter of 0.2 microns - 2.0 microns), the fog settles extremely slowly. Provided the generators are installed correctly, this provides two benefits: The smoke lasts a long time, and it does not settle on surfaces to any discernable level i.e. it does not contaminate.
How are the Smoke Generators triggered?
In the vast majority of applications, the smoke generators take a simple "relay" trigger from an existing intruder alarm system. This means that the premise managers still only have to operate one system and also there is no need to install masses of extra detection devices.
That said, all Security Smoke generators on the market can and do support their own detection which acts as a confirmation trigger for the system. This prevents the system from activating if the intruder alarm, for instance, false alarms. These detectors are referred to as "hold-offs" in that they prevent the system from activating until movement is confirmed.
How are the generators installed?
Smoke generators can be installed above ceilings or high on walls. The smoke is introduced vertically downwards.
Smoke is forced down and then rises forming a thickening barrier, which protects the Smoke Generating equipment, itself, as well as the premises and contents.
All 'smoke' will have a tendency to rise when it is first produced. This is because the smoke particles have a higher temperature than the surrounding air. In a short time the smoke will take on the ambient temperature of its surroundings and become quiescent. This natural convection effect can be used to great effect in a security application.
The Security Smoke market place has evolved over the years to a position where there is a large degree of choice on the market and many different methods of employing the systems. Below are a couple of examples:
In this example, a long run of rooms (imagine a series of individual offices adjacent to each other) can be protected using a single generator.
Many of the manufacturers now offer supplementary devices that add to the overall deterrent effect. These include white noise generators (very loud and produce a sensation not unlike sea-sickness in humans) and high intensity strobe lights (imagine driving into thick fog and turning your full beam on,....then times it by 1000!)
As mentioned, Security Smoke Generators have been in operation for a long time; however, most consumers are still unfamiliar with the concept. Here are some of the most common queries:
"Will the smoke damage my property?"
If the Smoke Generating equipment is installed and operated to the manufacturer's specifications then there is no possibility of damage or contamination. Systems have been used to provide protection to a wide variety of sensitive property including high value clothing, consumer electronics and even military clean rooms.
"What about computers?"
Smoke Generating units are used extensively to protect computer equipment. The dry nature of the smoke ensures that no deposition occurs on computer equipment. In addition, the liquid itself is non-conductive and non-corrosive. Tests have been conducted by a major international electronics manufacturer, which show that LCD modules and PCBs with surface mounted ICs are unaffected even when the pure smoke fluid is literally poured over them.
"What do the insurers say?"
Insurers throughout the UK now recommend and specify Smoke Systems. A number are also offering financial inducements to install. These include cash-back or premium reductions.
"What about the Police and Fire Brigade?"
In general the Police see the use of Smoke Generators as a positive move against intrusive criminals. Many Crime Prevention Officers throughout the country are happy to recommend the system.
The new Association of Chief Police Officers guidelines make provision for the use of a security smoke generating system. As well as this, some of the manufacturers of this type of equipment have achieved an accreditation called "Secured by Design" a scheme run by ACPO showing that the equipment is inherently secure and is designed to be as such.
Fire Brigade personnel appreciate the need for such systems and have stated that, as long as systems are installed as per the code of practice then they have no objection.
"Who can I get more information from?"
You can approach any of the manufacturers directly, and they will take you through specification, quotation and installation by either your own alarm company, or a preferred installer (some alarm companies prefer to stay within the remit of intruder alarms and simply supply the triggering outputs to the smoke system). Or you can ask your existing alarm company to source and install the smoke systems for you. Whichever way, remember that you are the customer, it is your premises and you need to be comfortable with the arrangements. The chances are, if you are considering a Security Smoke system, you have a definite need for it and it is important that the installation is done correctly the first time!
A final word on service and maintenance:
All too often the perception is that if a Security Smoke system has not been called into action in anger, then it is not really doing much and as such does not need to be serviced.
"This is very definitely not the case!"
Apart from being a condition of extended warranties and the British Standard, there are very good technical reasons for service.
All Security Smoke systems are powered permanently after installation and they maintain the heater source at the correct temperature through thermostat control of the heaters. Most employ at least 1Kw heaters and some employ heaters rated up to 3Kw. The consumable used by these systems has a shelf life (again this can vary according to manufacturer). If old consumable is used, it can detract from performance. It is of paramount importance that Security Smoke generators are inspected as a minimum once a year.
After all......you would not want it to fail when you actually needed it!