Room heating with different radiators

About this project

Recently I noticed that when I put some cloths on a radiator in my room, even though the heater power is not changed, the experienced temperature was lower that if the radiator was clean. This simulations are to validate this observation. Geometries made in Onshape: https://cad.onshape.com/documents/23cf8e2fcd9a79a6c726e2d2/w/3e90bc52673a685f643f9c04/e/13b4d519324aeebb3eff8ba7