Active solar heating systems are most cost-effective when they are used for most of the year, that is, in cold climates with good solar resources. They are most economical if they are displacing more expensiv. Selecting the appropriate solar energy system depends on factors such as the site, design, and heating needs of your house. Local covenants may restrict your options; for exam. Controls for solar heating systems are usually more complex than those of a conventional heating system, because they have to analyze more signals and control more devices (in. Before installing a solar energy system, you should investigate local building codes, zoning ordinances, and subdivision covenants, as well as any special regulations pertai. How well an active solar energy system performs depends on effective siting, system design, and installation, and the quality and durability of the components. The collectors an.