We looked at many of the "smart" smoke sensors on the market and decided that they are very expensive and don't work particularly well. The main problem with them is that they are stand-alone products and services that don't have whole home context. Whilst some can be linked with other smart home services, what we really wanted was smoke alarms and smoke sensors under full smart home control.
We wanted to use attractive, low-cost, 'dumb' smoke sensors and make them really smart and extremely reliable. This approach means we can deploy many sensors for less than the cost of one typical 'smart' smoke alarm like the Nest Protect. Each is powered via a protected 12V dc power supply which eliminates the need for batteries and this also provides extremely secure and reliable networking/signalling. Each one added becomes much smarter and is fully integrated within our smart home, adopting all of its capabilities. This includes local and whole house voice announcements, full alarm system integration and notifications.
Because these are just treated as sensors in our smart home, what happens when they detect smoke is fully under the control of our contextual smart home and it can make intelligent decisions and actions based upon all of the whole home context available to it. For example, it will react very differently to smoke detected in the kitchen, knowing that the kitchen is currently occupied.
Ideally, we would like the smoke sensors in our home to be invisible. Dumb smoke sensors tend to be much smaller which helps with this.
We are not fans of products like the Nest Protect alarm. It puts a lot of expensive electronics into something that is essentially a consumable item (the sensor in all smoke alarms have a limited lifetime). We have seen reports that some of these devices don't even last as long as 4 years and are also not covered under any kind of extended warranty. These manufacturers also want to lock you into their 'eco system' and effectively force you to replace them more regularly. It just doesn't make sense from an economic and environmental point of view.
Many manufacturers make and sell combined devices that may include a smoke alarm and CO alarm in one physical device. Whilst these may look good value of the face of it, these kinds of devices are not really a good idea.
Not only is this approach much more cost effective but it also provides very high reliability, a great user experience and loads of smart features. It also means we are not tied to one particular vendor or eco-system. Because these sensors are linked to our intelligent contextual smart home, it can decide what action to take should a sensor be triggered. This could be to activate the central alarm, an voice announcement or just a notification.
This approach uses standard CE marked smoke sensors (without audible sounders) or alarms (with audible sounders). We have configured them such that they use a protected power supply (providing battery backup) and all are linked via our contextual smart home such that it will provide both a local and whole house alarm capability, along side the advanced smart home features discussed here.
Our contextual smart home models smoke alarms as devices with a type called 'Smoke'. This means that when an event arrives from a smoke sensor (using a unified communications protocol), our smart home has all the right information and context to know how to handle it.
