For some time I have been interested in smart home subject. Finally during last months I made a few big steps and started implementing something on my own. I have started build it alone from available components from different vendors and integrated with Smarthome app coming from z-wave.me.
Currently my system consists of some temperature , window open/close, motion sensors, plugs, dimmers, thermostats. It works, I like it. A friend of mine has similar system with much more features and scenes, I have also implemented some scenes, associations. So light on stairs automatically turns on when someone wants to go up/down, I can turn off heating/lights in kids’ room when they go out, turn off TV with equipment during sleeping time to preserve energy.
But – is such home smart?
I asked myself this question for the first time when I have added integration of IntChart to my TV plug
- Power consumption of TV and decoder 160W
- When XBox is up – 200W
- Turn off 16W
Wait a second… 16W when nobody uses anything? While sleeping or outdoor? It is not smart.
Of course it is easy to integrate such scene that when leaving home and alarm system is armed all unnecessary devices are turned off. But yet it is not smart… just dummy power off. It works perfectly, gives results but what I miss here is kind of awareness of the system itself…
- Hello user… I have noticed that when you are out there are several devices still turned on. Do you want to talk about it? Some of them should be turned off
- Sure myHome… tell me more please.
- Refrigerator, Washing Machine, TV Set, lamps in bedroom
- Add to my Out scene TV Set and lamps.
- Done. But still your refrigerator is using 1.5kWh per day. It is visible 20% more then 2 weeks ago. Do you want to have a service check on it?
So smart home is monitoring what’s going on and tries to bring my attention to potential issues allowing me to save a few cents… or partially pay off my investment in the system 🙂
What do I expect from smart home?
- Be Smart
- Make my life easier, more comfortable
- Allow me to save money
- Make my life more ecological.
Maybe let’s skip point 3 for some time as in some term we can see some savings if system is used correctly but we do not expect it will pay off quickly.
As for point 2 – this everybody knows. Lights turn on/off automatically, heating automated, notifications. This is unquestionable.
Point 1 and 4 are related in my opinion. If my home is smart it allows me to save electricity, water, heating, better utilize my home equipment.
Here is list of use cases which smart home should implement to be considered smart and how can try to achieve this.
First of all smart home must be aware of the flow of its blood – meaning electricity, water, gas. Also all health parameters like temperature, humidity, presence, state of switches must be tracked. Without monitoring system cannot learn our behavior and cannot interact with us giving any valuable input.
When it comes to electricity we think about two items
- measure the consumption
- have power on/off capability
- tune power level – for dimmers or motors
I expect that smart system will:
- Monitor total power consumption level
- Monitor individual devices power consumption
- Monitor difference between Total and sum of individual consumption. Simply I assume that not all devices are monitored and I will accept some level of leakage.
- Warn if power consumption on certain devices drop or raise too much.
- Tune light/motors depending on my will or parameters like sunlight or humidity.
For example smart home should recognize that when everybody is (probably) sleeping I have power consumption on TV set. It should propose that he can ignore it this time, ignore forever or in future ask me for confirmation if all devices should be turned off.
Example chart above created using IntChart shows input information which can be used for further analysis. This diagram shows periods when power consumption is 16W – potential leakage. To make it more precise: when my TV and decoder are in standby mode power consumption is 16W what is too much. In that case I expect smart home will capture periods of standby and propose turning it off completely or even simply gently ask after some time “I see system is in standby for 15 minutes, if you do not disturb me I will shut it down completely in 15 minutes. When you are back home I will wake it up again.”
Wake up actions can be considered as set of proposals: coming back home basing on alarm system or presence monitor, turning light on in TV room or detection of movement, wake up hour
It is pretty much the same as for electricity. However it is rather rare to have more meters and one on supply pipe. Additionally we need valves in several places allowing to control flow of the water:
- Main valve
- garden watering valve
- emergency valve – for example near laundry
- flood emergency
Valves should work in correlation to some devices and scenes. What system should learn is reaction when there is flow not related to any activity at home – for example it should accept that washing machine is using water when watching machine is working but warn that water is still consumed when machine is done. This might indicate malfunction. Of course in this context smart home will know that laundry is not working, nobody is at home and garden watering system is off. First reaction should be emergency turn off of valves and sending notification to me. Of course similar reaction is expected when flood sensors are triggered.
- Smart home must learn how my home works and who lives there
- System must ask questions with several proposals and default reaction
- Home must negotiate media leakage levels with owner depending on seasons
- Smart home will try to guess and warn about potential home equipment problems basing on changes of media consumption and home parameters.