Let’s start with the realization that the energy entering the SunCatcher as sunlight and all other energy used in the SunCatcher is the same amount of energy that eventually will leave the SunCatcher as heat loss. And the longer the energy entering any structure stays in the structure before leaking out, the warmer the structure becomes. So, to raise a structure’s temperature you can raise the energy input, reduce the energy output or both. For the SunCatcher design this translates into a larger aperture (to collect more energy into the system) with more insulation and possibly a night time insulating curtain (to slow the amount of energy leaving the structure), and increased thermal mass (to hold excess heat for the colder, longer periods).
