In the contextual smart home humidity sensors can be used for many things:
We use common models for all the sensors and all the types of sensors connected to our Home Control System. Combined with technology abstraction this means that any sensor added inherits all the capabilities supported by each model and our smart home. Essentially, every sensor connected becomes instantly very smart. They can all generate based on absolute values, rate of change, upper and lower limits, etc. They can all generate voice announcements if required or trigger an alarm.
Because we use technology abstraction we can use many types of humidity sensor in our smart home.
Every humidity sensor provide humidity information into the pool of whole home context. The primary application for humidity sensors is local environment control in our smart home.
We only capture and process humidity to a resolution of 1%. There is no point in working with any higher resolution in the smart home and there are very few humidity sensors that are accurate to this level and they also need to be calibrated to get any where near this level of accuracy.
In our bathrooms the extractor fans are under intelligent control by our contextual smart home. Humidity sensors provide the information for it to best decide when the extractor fans should be on, enabling a zero-touch user experience. This means they won't come on just because a bathroom light has been switched on and they will always ensure the bathroom is mist free. This approach also ensures we save energy because the fan is only on when it needs to be on and not because it is being controlled by a 'dumb' timer.
When ever possible, we configure our humidity sensors to report humidity with a minimum of 7 seconds between readings. This enforced rate limiting works really well for all of the applications and use case we have identified. Our sensors also report only changes greater than 2% in real time (assuming 7 seconds since last update). We configure sensors to report every 30 minutes, even if the value hasn't changed. These simple settings mean that we never need to poll humidity sensors and that they provide a highly accurate and very timely view of humidity in any given zone. It also means that updates arrive only when required and this results in quite a small number of updates from a typical sensor each day, because it is only reporting significant changes. This has the side effect of making it very easy to ensure all humidity data generated by our smart home is logged.
