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| Friday, 06 February 2009 | |
APH Ltd & The GIRA HomeServer Smart Home Technology Helps Family to Abide by Jewish Sabbath RulesAPH Ltd of Leicestershire were asked by a Client to provide a ‘Smart Home’ solution for their five bedroom, three bathroom house in a prestigious area of Leeds. The main criteria was that the lights in the house should be controlled for a period of 25 hours without the family having to break the Jewish Sabbath rules relating to creating or extinguishing fire (Observant Jews consider the switching of any electrical item to be a form of fire creation). The Jewish Sabbath runs from 18 minutes before sunset on a Friday night until it is completely dark on the following Saturday night. During that time, Observant Jews cannot switch lights (or any other electrical item) on or off. So at specific times, dependant on the sunset/sunrise times of the year, lights need to be ‘timed’ to go on and off automatically without the intervention of any of the family. As well as managing over 60 internal and 10 external lighting circuits, a number of mains 230V AC sockets are controlled to allow, for example, hot plates to be switched on/off at certain times to bring food up to heat and then keep it warm prior to meal times.
Sunrise and sunset times vary depending on the time of year and the location. HomeServer3 has an inbuilt astral calendar which allows for seasonal variations in sunset/sunrise times and determines these times based on its location in the world (using longitude and latitude coordinates). All the changes are completely automated and so negate the need for the Client to check the daily (differing) times. The Client has very kindly provided us with the following explanation of how the ‘Smart Home’ system greatly benefits his family. “The Jewish Sabbath runs from 18 minutes before sunset on a Friday night until it is completely dark on the following Saturday night. During this time period of just over 25 hours, there are restrictions on certain activities for observant Orthodox Jews. These restrictions include kindling and extinguishing fire and, so by extension of this rule, switching lights on or off. The same also applies to electrical sockets. In times gone by Jews would employ a gentile to come in and light the fire and lights on a Saturday afternoon. With the advent of electricity, the lights could be left on all night and day, or basic timers could be used. I was never too concerned about switching lights on and off on the Sabbath. However, when I became more observant in my 40s, I wanted a more modern solution to lighting my home without having to break the Sabbath rules. I had heard about “smart” electronics and I thought that this might offer a solution. Having met a local contractor in Leeds and discussed what I was trying to do I found that they really did not understand the issues in play. They were perfectly able to allow me to time my lights, but only at fixed times and these could not easily be changed without asking them to arrange this. Clearly this was not a workable solution and would cause more problems than it solved. Further research led me to Andrew Hempsall at APH Ltd. Having patiently listened to what I was trying to achieve, Andrew recommended the Gira HomeServer product. This has an inbuilt astral clock, so it knows what time the sun rises and sets. This proved to be key to the solution he created for us. By using the HomeServer, a series of six separate Sabbath scenes commence automatically each Friday evening at exactly the right time and conclude with a number of lights switched on by Saturday night. These are then switched off manually when they are no longer required to be on. The scenes run as follows:
The system works perfectly with a seamless transition from one scene to the next. Outdoor lights are included and because many circuits can be dimmed, the entire process is energy efficient too. Because sunset is used as the trigger for the first and last scenes, seasonal changes are completely automated. Adding or removing lights from a scene is very simple as the scene can be called up using a web link, is manually modified (for example adding lighting in another room if needed) and then saved. As well as lights, the HomeServer controls a number of mains sockets which can be used for appliances such as hot plates in order to keep food warm. These can be set to repeat the same event each week, removing the need for unsightly timers plugged into sockets, or can be easily set for one off requirements. As well as the Sabbath there are certain other festivals where the same rules apply regarding lighting. These dates vary from year to year as they are dictated by a lunar calendar. Such dates are easily manually programmed into the HomeServer, again using the web link. Each successive festival is easy to create, simply by editing the previous events used. We therefore have a system which allows total flexibility allowing every light in the home to be timed. The timing memory also knows how bright or dim the lights should be which makes it very flexible and by using scenes we do not lose all the lighting when the system switches off, just the lights we no longer need. The added benefits of timed outdoor lighting in the week and simulated occupancy when away are welcome bi-products of HomeServer. I am not aware that KNX had been used for this application before. It works perfectly in a foolproof way, starting up automatically every Friday evening. There is nothing that can be forgotten, it just does its job. We are delighted with what we have ended up with and it is a credit to APH Ltd that they have understood our needs and provided such a fitting solution.” APH Ltd were delighted to offer a reliable and robust solution for this project and we have now have a ‘model’ based on a lot of development time which could be applied to many similar homes. This project has been ‘live’ for several months and continues to seamlessly and reliably deliver a lighting solution week after week. Our many thanks are extended to the Client for his involvement in ‘translating’ the many aspects of the Sabbath event into a working system for his home, without which none of this would have been possible. |





A GIRA HomeServer3 unit was the perfect solution for this project because of its ability to set scenes, run complex and large timed light sequences and allow the Client to input dates and times of various festivals and events (which change from month to month and year to year). 