[Viktor] wanted a system to keep his pipes from freezing. The common method of using heat tape works pretty well, but can be wasteful. Many people just turn it on for the entire winter. [Viktor] wanted to automate the heat tape’s power so that it only activated during times that the pipes could actually freeze. To do this, he rigged an ATMega8 to a temp probe and is using it to control an ATX power supply. Pretty slick [Viktor].
[via HackedGadgets]
Very cool and much more geeky than my solution would be. (An X10 module and transmitter run by a cron script on a server. Take the outside temp from someplace local like a 1-wire weather unit and turn on as necessary.)
Alternatively you you could use ‘sleep’ in an infinite while loop as I did to periodically email my external IP for ssh reasons. I was unaware of ‘cron’, I’ll check that out.
An elegant solution, though it’d be interesting to work out how long it would take to “repay the environmental damage” caused by ic manufacture, energy used to make parts etc. It may well be this still saves energy overall, I have no idea how one would calculate this.
He was probably more interested in seeing lower monthly power usage than making an impact on the environment tbh.
Thing is, even if he didn’t make this, the parts were still produced (and in a warehouse somewhere), so it’s really kind of pointless to take into account the energy used to make the IC, etc. it was already made anyways. Plus, things like that are made in such large volumes that the energy required to produce one unit is extremely small. Yay for saving energy and not freezing pipes!
didn’t know the Atmega8 generated that much heat!
;)
most people would just leave a faucet dripping.
cever hack though.
if you don’t want to use a temp sensor, consider using a NOAA weather station located near your house ( and connect to it over IP). It doesn’t need to be exact, chances are if it’s 36 degrees at your local weather station, it’s probably pretty close to that where you are.
Solve it any way you want to, but I’ve bought heat tape that came from the store with an indicator light and a thermostat (most likely a bi-metal strip that cycles on and off depending on the temp of the copper pipe it was in contact with)
Maybe there was some reason he didn’t just do that?
Maybe the built-in one cycled at too high a temp?
I appreciate the DIY sensibility, I really do, but it’s a lot of work considering most quality pipe heating tapes have a temperature sensor built into one end.
You can also buy very inexpensive 120v temperature sensors from most aquarium supply stores (I’ve use these to control gutter heating elements).
There are off the shelf solutions for this that are plug and forget for under USD$20. They’re even electronic, not the old bimetal strip. And for around $40 you can get a fully programmable thermostatically controlled outlet with daily time zones and all that jazz; I use one to turn on heat lamps for my outdoor birds when it gets under 50F.
Terawatts of power could be saved with megabytes of control; even a 286 is extremely powerful and sophisticated if interfaced with our utilities and applied properly. The ? is…How do we control our environment with so few options? Geeks must save us again!
This is a nice idea for someone with some time.
I bought a Walmart yard stick outlet timer used for Christmas lights. Then I wrapped a pipe as well as a few plants with lights so they would not die. They even melt snow.
I really think something like this should be made mandatory
He said he “acquired” some heat cable…It was probably a piece of bulk cable from a plumber.They don’t come with thermostats built in so he built one…and added some other features I love it personally
Or, just use a simple bi-metal thermostat. Turns on below 2 degrees C. Power ‘wasted’ will be saved by not running electronics year round.
I did something like this, only I used the Analog Devices TMP03/TMP04. Outputs a variable duty cycle signal, with ‘high’ of the signal proportional to temperature. – no need to poll it.
I would have just gotten a programmable digital thermostat then program my own microcontroller. Same result, more reliable, less complicated, cheap, simple, fast, etc etc.
Duhh – Icy Hot – the problem with an off the shelf digital thermostat is twofold – first – for the most part, they switch only 24V for the furnace, etc, not 110VAC and second, the sensor needs to be in contact with the water pipe, not measuring the room air temp from inside the units own box.
Again another case of OVERKILL!!
I have a tape heater in my garage that only comes on at 32 degrees F. It’s been there for 20+ years. It only comes on when the pipe gets to freezing.
The tyme spent doing this, in my personal opinion (yes I know the line about opinions), was wasted.
I usually don�t post in Blogs but your blog forced me to, amazing work.. beautiful
We could have used one of those 2 weeks ago when our pipes bursted.