Knowing what the weather outside is like and what it is likely to do in the future is a design factor in every home built today. Our homes are designed to survive certain predictable events such as minor earth quakes, strong winds, extreme temperatures and heavy snow or rainfall. In addition to these in-built characteristics, providing your home with current environmental and weather information is an important element in enabling it to intelligently adapt to the changing external environment. This can help save energy, make your home more secure, prevent damage and make your home more comfortable and easier to live with.
Simple automation, like turning on lights when it gets dark or opening vents in the conservatory when the sun comes out, is becoming mainstream. More complex and intelligent behaviour needs to be based upon accurate and timely external environmental data. Some examples of the weather data that can be collected are:
- External temperature
- Wind speed and direction
- Calculated sunrise and sunset
- Measured dawn and dusk using a twilight sensor
- Sunlight levels
- External humidity
- Whether it is raining and measured rainfall
More complex sensors can add:
- Air quality measurement
- Lightning strikes
- External smoke detection
- External noise levels
- Background radiation
It is all very well have a nice digital weather station transmitting data to a nice bright screen on your mantle piece using wireless technology but, if that's the only place the data is going, it isn't going to help your home adapt to the changing conditions. Information such as rainfall, wind speed and even wind direction can allow you house to shut vents and windows, that would other wise let the rain in or prevent windows being caught by gusts of wind and damaged. Conservatory roof vents are a good example of this. A temperature controlled vent is not going to close during a typical summer hail storm because all it knows about is the temperature outside.
You can also spend huge amounts of energy on air-conditioning and climate control in modern homes, when the reality of the situation might be that the weather outside is perfect and all you really want to do is open a few windows or vents. If your house doesn't know what the conditions are like outside, then how is it going to make an intelligent decision?
Our home has a number of weather sensors and we are still adding to the them.
There are a number of useful weather sites available online. Some can be 'screen scraped' for use in other services but, some also provide suitable interfaces:
Weather Underground provides a useful API and this is free (requires registartion) to developers, who will make few requests to the service.