.25 kwh/day Refeigerator

[AC_Hacker]

Originally Posted by MEMPHIS91

The drain hole is awesome. I had to jack up one side to make all the water run into the hole, but I simply remove the plug and let it drain into cup once a week.

No way to let yours drain continuously?

Originally Posted by MEMPHIS91

Yes a more accurate thermostat would be a plus. I have had some experience with arduino. I own 2 or 3, and might look into building one.
I remember see your build and the code in your thread, thank you for posting that.

If you're gonna use my code, bear in mind that I used a Teensy 2, which has different pin assignments than an Arduino. As I recall I spelled them out in the header of the code.

It should be noted that in my code, I included a routine that smoothed extraneous data so that your compressor doesn't kick on and off due to spurious data.

You would be making a major contribution to the civilized world if your code also controlled an LCD display.

Best,

-AC

[MEMPHIS91]

I can drain it continuously its just in a very easy kick spot. It only takes a second to drain and throw the water in the sink. But constant would be better.

I did look over your code, it is quite well written.
I did a pyromusical using arduino back about 4 years ago. It will take some time relearning but I will look seriously into designing one with a LCD display.
RGB LCD Shield Kit w/ 16x2 Character Display - Only 2 pins used! [NEGATIVE DISPLAY] ID: 714 - $24.95 : Adafruit Industries, Unique & fun DIY electronics and kits

[JimiQ]

I'll be a little off-topic, but let me share my fridge stats.

I have 220 liter (7.8 cf) refrigerator with 110 liter (3.9 cf) freezer in the bottom. It used to take 0.9 kWh/day in summer and 0.45 kWh/day in winter. But lately I "tuned" it up (with reflective foil between freezer and compressor and also between fridge and back coils) and it uses 0.38 kWh/day on average these days (15°C/59°F on the outside, 22°C/72°F on the inside). I am hoping for less than 0.3 kWh/day in the winter, when outside gets below zero (Celsius/32°F)

So, pardon me, but 0.25 kWh/day "freezerator" seems like no big wonder.

EDIT: Although my wife coming back from week long business trip changed latest usage to 0.45 kWh/day (she likes to keep flat a bit warmer, so it's like 23.5°C/74.31°F and likes to watch for long hours (it's actually between 15 and 25 seconds, but to me it's looong) inside of the fridge)

[jeff5may]

If you are throwing together an arduino board to be a thermostat, consider using a Dallas/maxim sensor. They are pretty darn accurate and don't drift or bounce around like a thermocouple or thermistor. If there is only one sensor per wire, the code is real easy.

The little brick I did up for the general purpose controller discussion works with an uno board and an eBay LCD keypad shield. I have the code posted on github, see the thread:
http://ecorenovator.org/forum/geothe...ontroller.html

As AC suspected at the beginning of the project, a single design was never fully developed. The list of functions varied from member to member, as did communication and sensing protocols. Many members upgraded to the Mega board to avoid running out of pins or comm ports. Even so, if you parse through the thread, there were a number of functional units built, with code that was tailored to meet specific design needs or functionality. You can pick, mix and match code from the builds to make your stamp do what you want.

I am in the process of throwing together another dirt cheap window heat pump as time allows for a buddy. I will be using the uno stamp I built last time to control it, and I may end up expanding the functionality of it to avoid having to install a defrost control board in the new (old) unit. Time is tight at present, so I have not been devoting much of it to the build. When I get the unit together, I will start another thread on it.

[AC_Hacker]

Originally Posted by jeff5may

If you are throwing together an arduino board to be a thermostat, consider using a Dallas/maxim sensor. They are pretty darn accurate and don't drift or bounce around like a thermocouple or thermistor.

The Arduino (Teensy) controller I built for my Freezerator did use a Dallas/maxim "1-Wire" sensor.

So 1-Wire is already in the Freezerator code.

In actual practice, I found that I was having occasional spikes that caused the compressor to start more often that it really should have. And that is why I included the 'smoothing' algorithm in the code.

I have pretty clear code for an LCD display in my CO2 sensor project thread.

In fact, the code is HERE.

Shouldn't be too hard to merge.

I went with a little LCD display because it was so easy to get code and to interface.

As the project progressed, I added a precision temperature and humidity sensor which allowed the calculation of relative humidity, so I got a larger display to show that information, too. I was thinking that my HRV controller might be programmed to respond to both CO2 and humidity. For your Freez-Frig, it wouldn't be needed.

Then there are BIG LED displays that would be more nifty, but you might need to do more thrashing around to gain that added degree of niftyness.

Best,

-AC

[MEMPHIS91]

Awesome thanks for the replies AC and Jeff, I will be looking through info for awhile now.
I'll let you know when my "no big wonder" fridge has made progress.

[MEMPHIS91]

I ordered the parts for the thermostat build. I decided to try a touch screen with adjustable set temp and swing degrees and of course display the current temp.

[stevehull]

Here is an easy way to provide a water drain and yet have a hole with no air movement. Just use some fiber as a "wick".

Capillary action will draw out the water and yet there is no hole to let in air. This feature is used on the ISS to move condensed water.


Steve