Friday, Nov 29, 2002 at 01:00
Rockhoppong is probaly right about the
test not being NATA certified
test. There wasn't enough real data to make any reasonable conclusions. The tests took a running amp draw at the top and bottom of a run cycle and divided it by two, this doesn't relate to any refrigeration performace. Some of the units where actually off and cycling because they had reached the temperature required. you really need to know how many amps were consumed over a given period to maintain a given load. The best way is to use am amp accumulator and run it over 24hrs and see the actual power used to maintain a given temperature. See how long it takes to move from 30C to 0C and the energy used. The draw down power is important, however you need to know what the refrigeration out-put of the compressor is, an example is the Engels 40lt fridge at 2.7 amps approx has refrigeration out-put of
42 watts. In an ambient temperature of 40C it will take the Engel
3 hours to reach -8C and will consume approx 7 amps running continuously, there are other fridges that will achieve this quicker and use the same amount of power or in some cases less. I'm only using the Engel as an example as I know that these figures are available. The point I'm making is that most 4x4 mag tests are done in house and don't set these tests up properly to help give any meaningful data to make an informed decsion. A good example of this is our inability to guess correctly temperatures once they get below 12C, so in most cases you may think your fridge is chilling product, but do you know what the temperature is, the best
test is to put a thermometer in your fridge at room temperature and see how long it takes to get down to 0C, then put it in the back of your vehicle and do the same thing,and see how long the compressor stays off at zero. There's not enough room but insulation is another great subject. The upshot is we'll never all agree on fridges which makes forums such as this so good.
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