Cooling Degree Days: using both wet and dry bulb temperatures
Cooling Degree Days: using both wet and dry bulb temperatures
(OP)
I have not been able to find any literature, but does anybody know if it is possible to calculate CDD using a combination of wet and dry bulb temperatures.
I ask this because I have projecting cooling demand for Delhi India, and comparing current cooling degree days when just dry bulb temps underestimate the continuation of cooling demand throughout the monsoon season, as the peak temperatures reduce but humidity remains high resulting in high demand in reality, whereas using just the wet bulb temps underestimates the demand during the peak summer season.
I combined the two using as I was using the Discomfort Index (Thom) and out of curiosity I used these the calculate the CDD (DI = (0.5* wet bulb temps)+(0.5*dry bulb temps)) and these appear to show a clear continuation in cooling demand in both peak summer and the monsoon period which is much more realistic of what actually happens.
Any thoughts welcomes!
I ask this because I have projecting cooling demand for Delhi India, and comparing current cooling degree days when just dry bulb temps underestimate the continuation of cooling demand throughout the monsoon season, as the peak temperatures reduce but humidity remains high resulting in high demand in reality, whereas using just the wet bulb temps underestimates the demand during the peak summer season.
I combined the two using as I was using the Discomfort Index (Thom) and out of curiosity I used these the calculate the CDD (DI = (0.5* wet bulb temps)+(0.5*dry bulb temps)) and these appear to show a clear continuation in cooling demand in both peak summer and the monsoon period which is much more realistic of what actually happens.
Any thoughts welcomes!





RE: Cooling Degree Days: using both wet and dry bulb temperatures
Best to you,
Goober Dave
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RE: Cooling Degree Days: using both wet and dry bulb temperatures
RE: Cooling Degree Days: using both wet and dry bulb temperatures
so hourly CDD = (DI - base temperature)/24
I know this is not an established method, but doing just wet bulb temps underestimates the effect of peak summer temperatures.
RE: Cooling Degree Days: using both wet and dry bulb temperatures
RE: Cooling Degree Days: using both wet and dry bulb temperatures
RE: Cooling Degree Days: using both wet and dry bulb temperatures
from google: "A cooling degree day is every degree that the mean temperature is above 65 degrees during a day. So, if the high temperature for the day is 95, and the minimum is 51, the average temperature for the day is 73. That would be 8 cooling degree days (73-65)."
RE: Cooling Degree Days: using both wet and dry bulb temperatures
Calculate the enthalpy using wet and dry bulb temps. Then calculate DB temperature that results in equivalent enthalpy.
RE: Cooling Degree Days: using both wet and dry bulb temperatures
However, as said, CDD are normally measured using dry bulb temps but this hugely underestimates cooling demand during the monsoon season as the humidity is an important factor.
In relation to calculating enthalpy, could you point me in the direction of a website/paper that outlines how to calculate that? Thanks
RE: Cooling Degree Days: using both wet and dry bulb temperatures