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[EnergyPlus_Support] Re: European radiators, EN442, baseboard rating

Your mass flow rate calc is correct.

I don't know how or why you put the zone air temperature in a equation relating to water temperature.

The zone temperature influences
1) the raditive exchange
2) convective exchange 
from radiator to zone air and from radiator to zone surfaces.

I don't have EN442, but I don't see how one can create a rated capacity of a radiative surface without assuming at least a room temperature which could be used to assume radiative zone surface temps & form factors, air temps, etc.

Chilled ceiling panels are always rated at specific zone air temperatures, and assume turbulant flow rates.

For radiative surfaces, the amount of possible heat transfer is more influenced by surface area than flow rate...at some point you can send soooo much kg/s through the radiator that you have zero temperature drop, but still the heat transfer from the limited surface at 82 deg C will not get bigger.

The rated performance is just an output based on a standard rating calculation and should not effect actual performance during simulation.

I suggest entering:
Rated Average Water Temp = (82+71)/2 = 76.5 
Rated Water Mass Flow Rate = 0.00003 m3/s
Rated Capacity = Autosize ... the program will escentially deturmine the "active length" of your unit.
Maximum Water Flow Rate = ...as per manufacturer data sheet or acceptable pressure losses

Reported Rated Capacity will be the US rating, you know the EU rating.





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