Category: 5.Solar Water-Heating Systems

Installation of large collector arrays presents specific piping problems. This section examines issues related to the installation of pipes, supports, and insulation; pumps; valves; and instrumentation. Generally, the plumbing involved in solar energy systems is conventional, except in cases where a toxic or non-potable heat transfer fluid is circulated in the collector loop. A general…

The equations presented in this chapter can be combined and used to model the whole system. The model includes all physical components of the system, such as the collector, storage tank, heat exchanger, loads, and heat losses from the system components, such as pipes and storage tank. Detailed models result in a set of coupled algebraic…

Many test procedures have been proposed by various organizations to determine the thermal performance of solar water heaters. Testing of the complete system may serve a number of purposes. The main one is the prediction of the system’s long-term thermal performance. System testing may also be used as a diagnostic tool to identify failure and…

The most important parameter that needs to be considered in the design of a water-heating system is the hot water demand over a certain period of time (hourly, daily, or monthly). The energy demand, D, required for the generation of sanitary hot water can be obtained if the volumetric consumption, V, is known for the required time…

One of the most important components of an active solar energy system is the temperature controller because a faulty control is usually the cause of poor system performance. In general, control systems should be as simple as possible and should use reliable controllers, which are available nowadays. One of the critical parameters that need to be…

Module design Most commercial and industrial systems require a large number of collectors to satisfy the heating demand. Connecting the collectors with just one set of manifolds makes it difficult to ensure drainability and low pressure drop. It would also be difficult to balance the flow so as to have the same flow rate through all…

Thermal storage is one of the main parts of a solar heating, cooling, and power generating system. Because for approximately half the year any location is in darkness, heat storage is necessary if the solar system must operate continuously. For some applications, such as swimming-pool heating, daytime-air heating, and irrigation pumping, intermittent operation is acceptable,…

In active systems, water or a heat transfer fluid is pumped through the collectors. These are usually more expensive and a little less efficient than passive systems, particularly if antifreeze measures are required. Additionally, active systems are more difficult to retrofit in houses, especially where there is no basement, because a space is required for…

Two types of systems belong to this category: thermosiphon and the integrated collector storage systems. These are examined in the following sections. 5.1.1 Thermosiphon systems Thermosiphon systems, shown schematically in Figure 5.1, heat potable water or transfer fluid and use natural convection to transport it from the collector to storage. The thermosiphoning effect occurs because the density…