Converting freezer to refrigertor
 

I read where an Australian converted a freezer to run as a refrigerator to reduce the eletrical requirments to run the refrigerator. Ha anyone on forum used a similar modification.
Bill Cook

Re: Converting freezer to refrigertor
 

Got a buddy who likes his beer. Has a nitrocharged pale ale keg setup installed in a freezer unit that has a box connected to it that makes it refrigerate instead of freeze. Cost him about $400 including the freezer.

Re: Converting freezer to refrigertor
 

I assume you mean a chest freeezer?

Just hang a thermostat thermistor in the the freezer so it runs at 38 instead of below freezing. Maybe?

Re: Converting freezer to refrigertor
 

No reason why that won't work in my opinion.

Re: Converting freezer to refrigertor
 

I bought two of these from the "kegman" ( I paid about 50 bucks a year ago...I see he is up to 67 now )

http://kegman.net/images/9025.jpg

to make an ultra low electrical use fridge out of a small chest freezer using solar power should the SHTF. I have one small chest freezer now, and I figure if the power ever goes, they will be a dime a dozen....it's the thermostats and the little bit of power needed to run them that will be hard to come by.....thus I have one and a backup.

http://kegman.net/9025.html

When I get some spare time ( whatever THAT is ) I'll hook up the little chest freezer with a Kill-a-Watt meter and see how much power it takes to keep it at fridge temps.

Re: Converting freezer to refrigertor
 

Not sure who that was. May have been me.

I found an article on doing this. I am no electrician or engineer, got a science background and some electronics knowledge and to me this idea/circuit made perfect low cost sense.

If you run this off mains (likely) you'll need to step down the voltage with a transformer from 240 or 120 V to 12 V AC and a bridge rectifier/ 9 or 5 volt regulator with ceramic capacitor to convert to stable DC for use in your operational amplifier circuit - all up, maybe $15.

The functional part of the circuit uses an op-amp to compare a voltage proportional to temperature from a NTC thermistor (negative temperature coefficient, which sits inside your chest freezer and is attached to the non inverting input or +) with a set voltage (inverting input or -). The op amp acts as a comparator and if the temperature voltage is below the set threshold the op-amps output will be driven high turning on a single NPN transistor (BC547) triggering a 12V/240 or 120 V AC mechanical relay (with diode to block back emf) powering the fridge/freezer....

The op-amp needs to be a single supply job like a dual LM311 or quad LM324.

If I find the circuit I will post it. It can be easily made for under $20 - $25

Most probably if this was a little hard to take you may want to just buy a ready made one...no biggie...

:smokin:

Re: Converting freezer to refrigertor
 

I picked up a new 5Cf chest freezer for $147.00 and ordered a controller for $80.00 that will turn power on and off when needed. I anticipate having about $250 in the completed project that should provide a much reduced demand for electricity. I plan on using a solar panel to charge a deep cycle battery attached to a 2500 watt inverter. In the interim I will be using it as a spare freezer for day to day food.
William S Cook
in Orlando

Re: Converting freezer to refrigertor
 

Yep, that's the same deal my beer buddy has....

Re: Converting freezer to refrigertor
 

After purchasing two six volt ( 6+6=12) golf cart batteries (used) I connected them to my new out of the box 1500 watt inverter it whistled and fizzeled to a stop, and would not reawaken. Lesson: don't wit until it is needed to verify it is working even if brand new. I then got my new out of the box 2500 watt inverter out and ran my 5.5 CF chest freezer off of it for 24 hours with no problem. I have now determined that the inverter power from the battery should be the item that is controlled by the thermal switch inside the freezer so that it does not run all of the time while the freezer is not running. (A waste of battery power) I am in the process now of recharging my two batteries using my thirtyfive watt 12 volt solar panel. Eventually the thermal switch will be set to control temperature at 36 degrees inside the freezer. This should greatly reduce the demand for power to have my chest type refrigerator. In the mean time I will use the chest freezer as a chest freezer for day to day usage and power from the utility company. I would welcom any suggestions or modifications to my emergency refrigerator plan. I am consdering purchasing another 5.5 cf chest freezer to use as a companion freezer.
William S Cook
in Orlando