The angle and direction of installation is also of great importance as it will effect the efficiency of the solar collector. Naturally you want the collector to receive the maximum amount of sunlight each day and throughout the year. As a general rule if you are in the Northern Hemisphere then the collector should face South and if you are in the Southern Hemisphere then the collector should face North. See diagram below.
The angle at which you mount the collector should roughly correspond to the latitude of your location. For example:
-Johhannesburg, south Afric has a latitude of 30degree South - the collector should therefore face north at a 30degree as the angle.
-NewYok, USA has a latitude of 45drgee North - the collector should therefore face south at a 45 degreeas the angle.
You do not have to be too careful about mounting the collector at the exact angle suggested. If your roof angle is within 10o+/- of your desired angle you can just mount the solar collector flush against the roof surface. The added trouble of adjusting the collector to a precise angle is not warranted as it will not result in a great improvement in efficiency.
If you are using the solar collector for space heating as well as hot water production, or if you just want a larger solar contribution, you will need a system that will greatly surpass heat requirements in the summer. As can be seen by the diagram above, the sun is low in the sky during the winter and high in the summer. Solar smart house designs will take advantage of this by having big North or South (depending on your location) facing windows allowing maximum absorption of winter sun, with large eves or veranda to block out the summer sun.
