Comments on: Refrigeration off the grid

By: RUSS

RUSS — Mon, 20 Jul 2009 23:13:15 +0000

fokes you might want to try this method if you have the room, http://fourmileisland.com/IceBox.htm no moving parts, no energy[fossle fuel of any kind] used, TOTALLY PASSIVE…. .I BUILT ONE AND IT WORKED LIKE A DREAM ! GOOD LUCK

By: David

David — Sat, 11 Jul 2009 17:53:19 +0000

A thought about thermal mass. If you dissolve salt in your water it will lower the freezing point. Then when the compressor is off the thermal mass will do its work (absorb heat) at a lower temperature. Could be helpful with a freezer.
Timers will stick closed because the switch gets corroded, then produces enough heat to weld the contacts together.

By: Uncle B

Uncle B — Thu, 29 Jan 2009 20:53:23 +0000

Found these on the web for my “Zero running cost, Zero upkeep” off-grid dream retirement home. The ymay be of interest to you!

Einstein Fridge – http://www.gomestic.com/Consumer-Information/Eco-Fridge-That-Uses-Zero-Electricity.285375
I have a dream home in my plans that is “Zero running cost – Zero upkeep” and survival oriented for the depression we are entering. This fridge and a solar model at: http://www.geekologie.com/2008/08/zero_carbon_footprint_the_sola.php

By: Ralph

Ralph — Wed, 10 Sep 2008 04:26:11 +0000

How about trying the tupperware thing with the timer. Drill a hole to run the wires through and then seal it up with some silicone sealant. Then, as a backup, put a hole thru your freezer near the bottom and just keep the timer tupperware in the bottom with the water tupperware. Should stay nice and dry with that frozen air.

Oh, and have you tried using milk jugs instead of the tupperware? Cheaper than tupperware and if you have neighbors with kids and no goats/cows, there’s your source.

By: Owen Davis

Owen Davis — Sat, 05 Apr 2008 09:33:09 +0000

Have just assembled a Carel micro-controller IR33S series, available in 240 or 24 V that has NTC type probe. The controller is powered and goes between the supply and the freezer. Probe goes into the top opening freezer. Installed this on a Fisher & Paykel Freezer 240V, 0.5 A, 220 Cuft. Am currently running trials but initial results indicate: Initial temperature drop from 25C to 3C takes 19 minutes. Without programming the micro-controller to compensate for over shoot at 3C, overshoots target of 3C down to 0.9C then returns to 5C when controller cuts in and reduces temp to 3C in 4 minutes. At 25C ambient and no internal thermal mass takes 24 minutes to return to 5C from 0.9C and controller to cycle again. This would result in about 10 minutes compressor operation per hour – no internal thermal mass or 20 watt hour – will complete trials with specific thermal mass load and advise results. At the moment this seems to be a good solution to have an efficient, large capacity fridge.

By: Jack Higginson

Jack Higginson — Sat, 17 Nov 2007 15:55:38 +0000

I stumbled across this page. Your fridge system is exactly what is done on many small sailng yachts, as the compressor can only be run whilst the engine is running, they use what are essentially freezers as fridges by running the compressors opportunistically when the engine is switched on (such as when manoevering into port etc.) Failing that, it is necessary to run the engine simply to run the fridge (and also charge batteries used to power the radio, lights etc.) so that is minimised. Very long distance sailors use solar panels, but they don’t have the luxury of fresh food and use packaged instead, and therefore don’t have fridges at all.

By: Barry Wright

Barry Wright — Sat, 13 Oct 2007 05:03:05 +0000

I reckon it is worth trying to switch the freezer on and off with a thermostatic switch rather than a timer.. More precise with temperature, and I suspect it may be running less time/day than with the current setup.. Also a Night-time override could be easily inserted to save battery strain in the pm, using the thermal mass in the water. Easy to set up to see what highest and lowest temps reached also. Most bits from radio shack style places.

By: ray

ray — Wed, 18 Jul 2007 18:31:10 +0000

we were paying 1.99/gal for propane and now the station stopped selling it….so i’m tired of paying up to 3/gal so i’m trying the cheap freezer-fridge trick….and curently modifying my trackers to accept 4 additional panels…..i tried running a small rv chest type refer plus a small 300 watt A/C and noticed my batteries are not keeping up…

By: Patrick

Patrick — Sun, 01 Jul 2007 06:56:42 +0000

Brenda: Why are you insulating the inside of the freezer?
It is ALREADY insulated

By: Patrick

Patrick — Sun, 01 Jul 2007 06:55:28 +0000

peltier ceramic heat pump -
they use TONs of power aka electricity.
It okay if you are travelling down the road feeling fine,
but if you have to generate the volts…. lots of Amps
are needed.

There are certain times when “peltier junction” devices are perfect.