As we increasingly experience summer weather during winter months, some Santa Barbarans are deciding to add air conditioning to their homes. The downside is that air conditioning draws significant electrical power that is generated mostly from fossil fuels, thus exacerbating the warming that this equipment is designed to counter, at least indoors. Even when powered by renewable energy, the production of any AC equipment can use a lot of resources. So if not air conditioning, then what other options make sense?
One possibility is adding exterior shading devices over windows that are bathed in the sun’s heat. These devices include fixed eyebrow extensions; trellises (with or without deciduous vines); vertical louvers or fins for east- and west-facing windows; canvas awnings that are fixed, manually adjustable, or even motorized; or mesh solar shades that slide in vertical tracks on either side of the window, which can cut out as much as 80 percent of the heat. These exterior shading strategies are more effective than interior-shading blinds or curtains and can dramatically reduce building peak heat gain while also improving visual comfort by controlling glare and reducing contrast ratios.
Another option is to change the glass in south-facing windows to high-performance glazing, which greatly reduces the need for exterior shading elements. To carry out this change, sometimes just the glass panels in old windows can be swapped out. At other times, the entire window frame and sash need to be replaced to get optimal performance. This latter approach is expensive but does have advantages beyond just keeping unwanted heat out.