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jedwards · 16-04-2008, 08:07

48W for the Coleman unit is worse case scenario. 0 deg F inside and 110+ deg F outside. At more realistic temperatures 40 deg F inside and 90 deg F outside power consumption is around 12W or 1 amp.

If you want to compare the two it is vitally important to recognize that Rankine and Stirling are DIFFERENT animals. The Rankine will consume what it consumes and is controlled by an on/off cycling or Duty Cycle. The FPSC literally turns itself down, very much like a "dimmer" switch, so it only provides enough heat lift to maintain the set point temperature. This means a smaller capacity FPSC unit can provide comparable performance to a larger capacity Rankine and the FPSC will use the least amount of energy possible (as of 4/16/08) to perform the same job. If you were to only look at running draw, the low cost Twinbird FPSC will use about half the energy of a typical compressor sized for the same task. If you add in the surge loads associated with the on/off cycling of the Rankine compressor then the discrepancy grows even faster.

If you want to save money, find a Coleman online or buy through Global Cooling. If you want the minimum power consumption in a portable "Coleman" type unit the the SC-DF25 is it. It uses VIP insulation for the lowest heat leak and can hold below -40 deg C/F if for some reason you wanted it to (maybe you have some awesome fresh fish you want to keep that way for 6 Months ;-)).

16-04-2008, 08:07	#34
jedwards Registered User Join Date: Apr 2008 Posts: 24	Power 48W for the Coleman unit is worse case scenario. 0 deg F inside and 110+ deg F outside. At more realistic temperatures 40 deg F inside and 90 deg F outside power consumption is around 12W or 1 amp. If you want to compare the two it is vitally important to recognize that Rankine and Stirling are DIFFERENT animals. The Rankine will consume what it consumes and is controlled by an on/off cycling or Duty Cycle. The FPSC literally turns itself down, very much like a "dimmer" switch, so it only provides enough heat lift to maintain the set point temperature. This means a smaller capacity FPSC unit can provide comparable performance to a larger capacity Rankine and the FPSC will use the least amount of energy possible (as of 4/16/08) to perform the same job. If you were to only look at running draw, the low cost Twinbird FPSC will use about half the energy of a typical compressor sized for the same task. If you add in the surge loads associated with the on/off cycling of the Rankine compressor then the discrepancy grows even faster. If you want to save money, find a Coleman online or buy through Global Cooling. If you want the minimum power consumption in a portable "Coleman" type unit the the SC-DF25 is it. It uses VIP insulation for the lowest heat leak and can hold below -40 deg C/F if for some reason you wanted it to (maybe you have some awesome fresh fish you want to keep that way for 6 Months ;-)).