# Weird radiation results in winer and summer

I have ran two radiation analysis on ladybug but i have weird results. One is on 21/6 in summer which should have the most radiation data in theory in China, the other is on 22/12 in winter which should have the least
radiation. However, the radiation result in 22/12 is lager than the result in 21/6,how can it be ?

I have upload my definiton and Rhino model, Anyone have suggestions ?Thanks! radiation result in summer and winter.gh (425.2 KB)radiaiton model.3dm (55.2 KB)

It can make a lot of sense depending the orientation of the surface you are analyzing. For instance, for a south facade your radiation will be larger in winter than in summer becouse of the sun’s altitude. For a horizontal roof, you are right, the radiation should be larger at summer time.
-A.

The simulated radiation result is shown like you said. But if the city location is in Shanghai ,whose altitude is on the north of the Tropic of Cancer ,no matter in summer solstice or in winter solstice. What’s more, the sun altitude in summer solstice is higher than in the winter solstice, which should make the radiation and the sun hours in building be larger than in winter solstice in theory ,but the result is opposite. I have also uploaded the definition of the sun hours simulation in Shanghai, the front of the simulated building have no screens, but the simulated result of the sun hours in winter have two hours more than in summer, which does not match the theory and the fact. So I think that maybe the sun hour simulation make the result.radiation result and sun hours simulation in summer and winter.gh (461.9 KB) radiaiton model.3dm (55.2 KB)

I have checked the sun path in summer solstice in Shanghai, the sun’s position located on the north of the simulated buildings. Shanghai’s latitude is 31°，and the latitude of the Tropic of Cancer is 23.5°.In theory, the sun should appear on the south of the buildings ,not on the north of the buildings. The weather data maybe the main problem

This is just a visalization and no the real position of the sun with respect with each of the buildings. If you change the center point then all of the buildings can be at the north part. But the results will bethe same.
From this only image it looks that the rof is getting the highest value. So what is the problem?
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OK.
I checked your file and i think i know what is going on.
You are asking the radiation for a specific day in summer and winter. Seems to be that for this specific day the radiation in winter is higher than in summer.
I did an annual check and there you can get what you expect. I suggest to create a 3d map to see the distribution of the radiation for all year’s hours.

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I will check, thanks for your help!