Security Alarms & Sensors
There are many alarm systems on the market from the cheaper DIY installations, to the full remote monitored alarm services. These all pretty much remain isolated systems though, with no connection to enviromental control and home automation. Our thinking is that the security system, alarms and sensors need to be an integral part of any Home Control System (HCS).
Many of the sensors used can support multiple services and functions. Temperature sensors can be used for heating and colling control as well as for fire detection. PIRs can be used to detect occupancy and as well as intruders.
PIR Sensors
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Passive Infra-Red (PIR) sensors detect the heat given out by the human body and can be used to detect intruders within rooms. In addition they can be used to detect occupancy of rooms and buildings and drive environmental conditions such as lighting and room temperature.
PIRs can be bought for use in different situations. Some have focussed sensitivity for corridors, some are designed to stop false activation by pets. 360° PIR sensors can be mounted in the ceiling and used to detect entry and occupancy from all directions. |
Magnetic Sensors
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Reed relays are simple switches that are activated by the presence of a magnetic field. Typically these are used in door or windows contacts.
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Reed relays are used inside magnetic door contacts and the plastic housing aloows both parts to be recessed into a door and door frame.
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Reed relays are also used in window contacts and these are designed to be fixed to the frame surfaces.
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Pressure Sensors
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Stair mat sensors are used under carpets and have a pressure sensors to detect when they have been stepped on.
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Beam-break Sensors
These sensors provide a beam of light between two points and detect if the beam is broken. The beam is usually infra-red and not visibile to humans. Some systems use lasers to provide high accuracy and reliability over long distances. Beam break sensors are useful in situations where there is no physical deterent or other means to detect entry by a person, such as a gate.
Temperature Sensors
Although not commonly used in many homes today, many homes that have climate control or home automation use temperature sensors or thermostats in the rooms to enable control of heating or cooling systems. These can also be used to detect extreme temperatures and provide an early indication of a fire.
One of the key challenges in installing temperature sensors in each room is in siting them and wiring them up. Wireless sensors are available but they tend to be quite large and obtrusive. Designing them into to a new build should be a requirement on any new home.