How does it work?
Very simple. Or so does one might think…
At first I thought that connecting the machine to the hot water line would be it. Simple and effective! But after doing some research I quickly discovered that this was not the solution. Hot tap water is way too hot for doing your laundry, so it needed to be mixed with cooler water too something like 30’c / 35 ‘c.
Not wanting to void warranty (or at least as little as possible) on my brand new machine, I wanted to mount the system externally instead of inside the machine.
I bought a few solenoid electric water valves on E-bay for next to nothing. The idea is to alternate the hot and cold valves, and thereby mix it to a reasonable 35’c.
When the valves arrived, I started hacking together some hardware for controlling the valves. The ‘brains’ consist of a PIC16Fxxx programmed to open the valves. To interface with the microcontroller I used a light switch and a blank plate. The switch triggers the start of the program on the microchip, and the blank plate contains two leds. One power led, and one status led.
Does it work?
Yes it works! The machine normally would draw 2000 Watts when heating the water. Now the peak usage is down to as little as 200 Watts (the motor turning the drum).
Furthermore I discovered that the stand-by usage was rather high. The machine would use up to €35,- electricity a year just for being stand-by….. So I did write a few extra lines of code, added a SSR, and solved the stand-by problem. Now after 2 hours the electricity to the machine is cut, and it stops sucking energy from the socked. The only thing left using power is the microcontroller including voltage regulator, and switched PSU. This microcontroller uses only €1.40 a year, so mission complete!
Total electrical savings:
Saving on heater: €64
Stand-by savings: €33
Total electrical savings €97,- : ) ( I know gas is not free, but it is a lot cheaper)