There are two ways to run a solar heating analysis: as steady-state or as transient. When run as steady state, the time specified on the Solar Heating dialog does not change throughout the calculation. This is ideal for computing the “worst case” solar heat loading on an object during the heat of the day. Also, this regime is useful for determining seasonal variations in the peak solar loading.
To study the variation of solar loading over a longer period of time (either within a single day or over multiple days and nights), a solar heating model can be run transient. The time and date specified on the Solar Heating dialog are that at the beginning of the simulation. If analyzing diurnal heating over a long period of time (several days, for example), we have found that it is convenient to divide a day into 100 time steps. This is a time step size of 864 seconds.
If buoyancy effects are to be studied, then a significantly smaller time step will be necessary.
When running a diurnal solar analysis, it will likely be important to vary the sky temperature with time so that the appropriate value is used during day and night. Likewise, define the sky emissivity to be temperature-dependent to properly represent the reflective effects of ambient light and cloud cover.
The two result quantities that provide the most insight into the effects of solar loading are Temperature and Solar Heat Flux. Solar heat flux is enabled automatically for Solar applications, and is included in the Global Scalar Result list.