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Wired vs Wireless?


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Im sure most of the experts here will say wired alarms are better and more secure but I do believe I will need to steer more towards wireless.  I'm basically wondering how bad would it be to have wireless and what are the main reasons not to use it. 



Well, you already know what I think about wired vs wireless so I won't belabor the point so will stress the pros / cons.




- Easy placement

- No wires

- Fast install

- Allows extra coverage for wired areas

- Covers areas not normally accessible by wire




- Long term costs

- Battery replacement 

- Unexpected maintenance

- Potential to be jammed

- Range

- Different thresholds for operating temperature

- Requires basic understanding of limitations

- Some do not use common batteries


If you really need to use wireless sensors the good thing is that the technology has come a long way from 10-15 years of the past. Most sensors are able to provide at least 2-5 years of service before a battery replacement is required. It should be noted regardless of the sensor type (wired / wireless).


You must ensure a walk test is completed when commissioning the alarm system. A walk test must be performed at a minimum during summer and winter to ensure the sensor(s) are properly calibrated for detection. Do not accept anyone telling you to follow the manual (which you should) and all is well.


Which goes to the next point you will install all sensors per the makers maximum - minimum heights. You will not install any PIR sensor in the FOV of any heat register / cooling vent. Nor will you install any glass sensor where drapes / curtains will reduce the detection rate of the glass sensor.


Consider a few dual tech sensors which helps to avoid lots of false alerts as they incorporate microwave / IR. Never allow glass sensors to be tested simply by a key chain test or a slap test.


Failure to follow these basic guidelines will result in false detection or no detection. If you intend to install pet immune sensors verify the (weight) LBS these sensors are capable or not capable of detecting. When installing PIR sensors most if not all unless you're spending gobs of money require a object to sweep past the sensor array.


Better sensors do not require this silly annoyance or have this limitation. In all cases no matter how or where you have installed the sensor an *Attack Time Test* must be completed. This test ensures the maximum / minimum detection will pick up slow to fast moving objects.


Most if not all sensors tell you they auto compensate for temperature and humidity. I can tell you for a fact you better find out at what threshold it will continue to operate in their sweet spot!


Meaning, if you increase the temperature to say 85-90'F let me know how far you got clear across the room before it detected you! In the same vain use something to shield yourself and see if the sensor detects the movement. Keeping in mind the reliance on heat signature is one of the easiest methods to circumvent.


This is why dual tech and creep sensors are deployed in many high security installs. As some also use infrasonic / ultra sonic to negate the need for temperature or object movement. Some of the military installs we did measured air displacement which took into account actual moving air from air vents and registers.


These sort of sensors are extremely hard to circumvent as they know exactly how much CFM's are moving around in any given time period.


So essentially if you **** in my home I will know about it in a heart beat!



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Teken covered it well. Simply put, wireless is inferior in every way except the ease of providing coverage where wiring isn't feasible or desired.


The upfront cost is significantly more expensive for wireless vs wired, not just the long term due to batteries. A simple wired sensor and 30 ft of wiring is about $10 max. A wireless sensor has a minimum cost of $25 each plus the wireless receiver to get started. Many sensors are north of $40.


The other Con I would add to the list is aesthetics. Most wireless sensors are external mount while wired are hidden in the jamb with minimal modification.


It's really challenging to provide coverage for every window in your house with wireless, although possible. Especially in a window bank, but a single wireless transmitter with a loop series of closure sensors makes it more feasible.


With all that in mind, it's absolutely possible to provide ADEQUATE security in your home using wireless. About half of my sensors are wireless due to the challenge or wiring to some areas of the house. Provide coverage with break sensors, closure, and PIR motion so that no single room relies upon only one sensor, especially if it's wireless. In one room, I don't have closure sensors on the windows. However, I have a glass break sensor and a motion sensor in that room so it's unlikely they could enter there without detection. And the hallway outside that room has also a motion sensor.

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Other things to keep in mind depending upon the alarm system these are the most common features seen. While others are unique and proprietary to competing products or vendor customization based on what industries are being catered to.


- Tamper: If the case is opened


- Battery: Some indicate battery level, others indicate install time stamp, while others indicate hours of use.


- Heart Beat: Many systems can be set to poll / push their status based on either a set time 12, 24 hours. Others this is customized to suite the needs of the user.


- Signal Strength: Many systems will allow the user to see the signal strength of in range / out of range.


- Self Calibration / Auto Adjust: Better sensors upon boot up self calibrate and compare to a known value. More advanced sensors will auto adjust and compensate for temperature / humidity.


- Anti Mask: More advanced sensors are designed to negate people from using spray paint, laser, or other mediums to cover or shield the sensing lens.


- Creep Sensor: More advanced sensors offer dual lens to capture moving object directly below the FOV. This prevents a person from hugging a wall to avoid detection.


- Adjustable Lens: Some makers offer replaceable lens to allow them to operate in unique areas / environments. The most common are those used to monitor narrow corridors / hallways. The FOV is extremely focused and offers a large spread and is designed for forward movement detection.


Other things to consider should you wish to go the route of wireless sensors. Ensure you can purchase and have on hand the specific batteries these units use. Many systems have gone away from the common AA, AAA, and now use A123 cells, coin cells and some even use proprietary flat lithium cells to reduce product size.


But keeps you tied to the vendor as the batteries are not available over the counter. Keep in mind the stated battery life is based on XX activation's etc. 

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I am not going to argue that wireless is better than wired (its not) but do want to add my two cents though.


Elk has two way communication wireless. It will send the signal out from the sensor and make sure to receive a signal back from the panel knowing it was received. So this is better than just the normal one way "send signal who knows if it was received" of the past. I have a large home of about 4500sq ft with around 20+ Elk 6021s and 9 smoke detectors and I have never had one signal loss. I even have less sensitive zones were I am using the Honeywell wireless sensors (5816OD) and a 5809 Heat detector in my garage with no problems. Both types will report a trouble to CS if your battery is low or communication was lost during "checkin".


I also installed a few Elk systems for family and friends were wired was not an option, all of which have had no issues.


Also window manufactures will void your warranty if you drill into them for sensors. So then theres that too.


So while wired it better its not always an option and if you cant have wired doesn't mean wireless is bad. Sometimes wireless is the only way to go.


/end rant

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