Solar collector tilt

Solar systems should be designed to match the heating demands with the solar energy intensity that varies throughout the year. In the northern hemisphere, a solar thermal system will receive less solar radiation in the winter than in summer. To improve the seasonal solar energy collection, the solar collector can be tilted so that it would be more perpendicular to the sun’s path when the heating demand is greatest. Tilting of collectors (from horizontal) should be done to maximize the radiation collection skewed for usage. Thus a system that is providing heat for the winter should have a tilt angle equal to the site’s latitude, plus up to 15 degrees; a system for year round heating should have a tilt angle equal to the site’s latitude. Table 2.2 lists collector tilt angles at selected locations for maximizing winter solar energy collection.

Maximum radiation can be collected when the collector is faced due South in the Northern Hemisphere. If the system must be East or West facing, using a Westerly azimuth is more optimal than an Easterly one since the collector can take advantage of the warmer part of the day.