Funtamental Principle Solar Screens

One needs to acknowledge the laws of geophysics to optimally orientate the building and different functional units based on the sun's position relative to the global coordinates of the building.

The lessons to be learned is that heat sensitive areas (say patient's ward) is best located to the west (or the south), building preferably an overhang (or have an awning) protrusion, an ventilation duct at the top allowing the warm airflow from the bottom floor to escape permitting the entry of cooler air; the floor needs to have a high mass (instead of carpets) to absorb the thermal energy incident from the window and that appropriate solar shading of the window (be this trees, or) with solar shade will reduce the thermal energy and visible light penetration inside the room. The first two slides below shows the empirical relationships for a double glass window pane structure having three positions of the screen material, at the front, interposed between the two glasses, and at the rear/inside of the room.

The same can be developed for a single pane window as shown below.

Effectively placement of solar screens in the front of the glass pane considerably reduces the heat transport into the room, will also reduce the light, by allowing these screens to be manually or electrically raised or lowered by a crank manually or electrically driven mechanism from inside the room.

These solar screens from glass-woven opaque fibers are very popular in European houses and hospitals, in combination with awnings. The optimum positioning is that the integral screen and its frame is mounted in the outside of the room, nut it may also be fit inside the room, but in the latter case its effectiveness is reduced, though the screen is protected from the vigorous of dust and rain and wind. Some examples, amongst others of solar screen application, in a modern house is shown in the last slide.