Manufacturer performance curves
Manufacturers have determined performance of their coolers with different methods most suitable for their target applications:
- Kryotherm: thermoelectric coolers were installed on a box with outside dimensions 310 x 550 x 310 mm³ and 40 mm PU foam insulation.
Cooling capacity is given for the recommended, i.e. efficient operational parameters. The temperature difference however refers to ambient air
temperature and internal cold heat sink temperature.
- Elmeko: thermoelectric coolers were installed on an uninsulated cabinet with outside dimensions 300 x 500 x 300 mm3. Cooling capacity refers to
outside ambient air temperature and internal cabinet air temperature.
- Noren: heat pipe cabinet coolers were installed on uninsulated cabinets of 24 x 24 x 16 inch3 resp. 24 x 24 x 48 inch3 for the more powerful models.
Rated cooling capacity is the net cooling capacity of the heat pipe cooler, i.e. the cabinet heat dissipation capacity has already been substracted.
Cabinet Cooler Selection Tool assumptions
For comparison a somewhat standardized convective heat transfer scenario for internal and external walls was chosen.
Internally forced convection heat transfer with a certain value for the heat transfer coefficient was assumed.
Cooler fans do create forced convection heat transfer on the inside walls,
however depending on fans, orientation, internal flow obstructions, size of the box and other influences the heat transfer coefficient will vary locally
and the average values will so, too.
On the outside of the box natural convection is assumed on top and all walls. If a box is placed next to another box or heat source the heat flows
will thus not be predicted properly.
The chosen heat transfer coefficient values are average values from a number of CFD simulations.
Bear in mind that these values may easily vary +/-50% in different conditions and environments.
With the standardized convective heat transfer scenario the net cooler capacities can be calculated (because of the above mentioned factors influencing
the performance this calculation remains an estimation).
The temperature profiles on the inside and outside walls are for illustrative purposes.
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