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Considerations When Selecting Appliances
for Off-Grid Living:

Refrigerators and Freezers

    Conventional Refrigerators and Freezers use electric compressors to cool and circulate a cooling fluid. This architecture requires a tremendous amount of electricity. Indeed, electric refrigeration is often a very large component of an off-grid home's total power budget.

    SunFrost RF-12 Refrigerator on Pedestal Base A good idea of the power required can be gained by examining the required energy efficiency placard required to be afixed to all new appliances. The placard will state an estimated dollar cost and number of kiloWatt hours per Year (kWH/yr) used by the appliance in a typical application.

    To get an estimate of your refrigerator's energy requirement for the System Design Worksheet:
  • Divide the estimated kiloWatt Hours per year by 365 days/year to obtain an estimate of required kiloWatt hours per day.
  • Multiply this value by 1,000 to get estimated Watt-Hours per Day
  • Divide the estimated Watt Hours per Day by 2.4 hours to represent a 10% duty cycle for the refrigerator. This represents the estimated power requirement, in watts, for the refrigerator when the compressor is operating.
  • Enter into the table the estimated power requirement, and the 2.4 hour per day running time.
  • This is only a rough estimate, and does not include such intermittent loads as automatic defrost, ice makers, etc. But this procedure will yield a pretty good overall estimate of the load your off-grid power system will have to handle.

    SunFrost RF-12 Refrigerator on Pedestal Base ConServ/Eco-Fridge Refrigerator/Freezer Special high-efficiency electric refrigerators are manufactured by SunFrost. European brands of Refrigerators and Freezers such as ConServ are also very efficient. Also, the most modern refrigerators are dramatically more efficient than those of only a few years ago.

    Of course, you could also consider a refrigerator or freezer that requires NO electricity at all! Refrigeration utilizing the Ammonia absorption principle requires only a heat source to drive their cooling cycle. Most of these ammonia-cycle units use natural gas or propane to provide the neccessary heat source. The required flame is little more than a small 'pilot light' and the units use very little fuel. Most off-grid aplications would utilize units configured for propane.

    With no moving parts, these units are absolutely silent and last for a very long time.

    Crystal Cold 18 cu. ft Refrigerator Frostek Propane/LP Freezer Current production units are manufactured by Servel/Dometic, Frostek and Crystal Cold. The Crystal Cold units, in particular, look just like everyday refrigerators or freezers.

    Servel Propane/LP Refrigerator Be aware that some of these propane refrigerators DO require periodic maintenance. Specifically, the Servel/Dometic units require cleaning of the burner and related components every six (6) months. Some disassembly of the unit is required, and an air compressor is very useful for cleaning the small metering orifice.


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Last update: 5MAY2003

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