How are radiator outputs calculated?
Heatpunk calculates actual radiator outputs with the below formula. This allows us to easily consider differences in flow, return and room temperatures.
where
P = heat emission from radiator (W, J/s)
P50 = heat emission from radiator with temperature difference 50 oC (W)
ti = water temperature inlet (oC)
tr = water temperature outlet (oC)
ta = surrounding air temperature (oC)
n = n coefficient
The other way you can calculate radiator outputs is by calculating the correction factor based on temperature differences and the specific radiator being used. To calculate the correction factor you should use the below formula.
where
P50 and n are as above
trad = mean radiator temperature
troom = room temperature
dT = design temperature
In the room breakdown of Heatpunk it should give you the total heat loss of the room and then radiator outputs will be calculated based on the flow temp you have used. The rads built into the software are based on Stelrad classic compact, so if you are using heat emitters where the outputs differ significantly you should add them in as a custom radiator to ensure the outputs are calculated correctly.