Solar Refrigerator

[kaypsmith]

With so many RV’rs considering changing from the absorption type refrigerators to residential type, and with so much emphasis on what type inverter to use, has prompted me to take a look at an alternative method of refrigeration. Inverters of course are costly, and not very energy efficient because they are very high into using electronics for changing the DC “direct current” to AC “alternating current”, which produces heat which must be dissipated, usually by means of a fan, “more energy expended”,   then  to be used by a 120 volt appliance that is built for on-grid use. While many of the home units are energy efficient in their own nature, they are not energy  efficient  at the 12 volt level, because of the overhead that is used in changing 12 volts DC to 120 volts AC. My thoughts are to use 12 volts DC for the entire operation because DC speeds can be controlled by simply lowering the voltage to run slower and increasing the voltage to run faster. So the research began, I have found as many of you already know, that there is a solar market in play already. I have located refrigeration units that are available in this market which are well suited for the RV industry. Here is an example, not an advertisement for this company, but merely for reference. There are several other companies in place, and research to find what would meet your goals is in order.

http://www.ebay.com/itm/VoltRay-Solar-DC-Powered-Refrigerator-11-1-cu-ft-/111943373518?hash=item1a105852ce:g:vfkAAOSwI-BWIWJ7

A unit such as this can easily be used  for an RV, and can even be self sustainable with proper solar peripherals in place, making it very handy for boon-docking.

If I were to replace my unit now, I would very likely go with this newer technology. Also another advantage for changing to this method, the investment can be used as a tax deduction, making it an even better investment.

[wolfe10]

Yes, 12 VDC refrigeration has been around for a long time-- every one of our sailboats had 12 VDC refrigeration.

 Not sure why it is styled "solar powered"-- sounds like a "buzz word".  The source of 12 VDC, whether shore power/charger, generator or engine-driven alternator really or solar makes no difference.

[kaypsmith]

In doing research, I had no hits for dc refrigeration, but many on solar. It think it is a "buzz word". I'm sure it is a sales pitch, as many have now become used to the word "solar", for lowering ones electrical bill. I knew that it existed, but many have been sold for years in much smaller units than what are now available. I currently looking at a 14 cf freezer for my home to replace an older 12 cf ac model. Though the chest freezers use less current than upright models, I want the ability to stay frozen in the absence of power, I live in a very rural area and have frequent power outages. 

[manholt]

Kay.  The land of the Concord Mine!  Where do you get a 14 cu. ft. box freezer that runs on battery's?

[dickandlois]

Carl ,using the link supplied by Kay, this unit comes up!

http://www.ebay.com/itm/VoltRay-Solar-DC-Powered-Refrigerator-11-1-cu-ft-/111943373518?hash=item1a105852ce:g:vfkAAOSwI-BWIWJ7

Might be a starting point.

Rich.

[obedb]

Solar in front of refrigerator. I think I smell a tax payer subsidized product. 

[obedb]

Kenworth offered a refrigerator/freezer with a twelve volt compressor. Had one in a 96 model. Brett mentioned they are used in boats. So now they are solar refrigerators?

[kaypsmith]

Yes 12 volt refrigerators have been around for quite a while, and I think that the solar "nuts" probably have hijacked the product and renamed it.

Since most solar gathering devices are either 12 volt, or 24 volt, they have chosen to make use of the already existing technology. As I was showing in the OP, inverters are just a means to transform the lower voltage to 120 volts. It can be done with a simple capacitive winding, 12 to 120 or more, which is no real feat and causes almost no loss of energy

The real feat is to use an electronic alteration of the direct current to make it become an alternating current which uses expended energy, which I refer to as overhead. The largest innovation in the process with the advent of solar research, and the NASA program, is to make it more affordable in larger units, which in turn will make the use of alternative electricity more attractive.

Insulation is a large factor in making the use of less energy to enable better use of the so called alternative energy. And as I pointed out in the OP, tax incentives are in play if one decides to use one, "tax-payer subsidized product", and I'm reasonably sure that some business has taken advantage of some subsidy. But it is what it is, thanks for responding, and hope that the post has been useful to others.