Читать книгу Solar Water Heating--Revised & Expanded Edition - Bob Ramlow - Страница 42

The traditional type of pump used in a solar water heating system is a 120-volt AC pump. These pumps are readily available in a variety of sizes and are also used in traditional hydronic heating systems. Because these pumps are mass produced, they are less expensive than specialty pumps designed for the solar industry. There are many manufacturers of these pumps, which come in a variety of configurations. These pumps are reliable and last for a long time. Because of their low price, many of these pumps are not field repairable, so when they break, they are just replaced. A few manufacturers make pumps called cartridge circulators. These have a cartridge inside the pump that can be replaced without having to take the whole pump housing (called the volute) out of the system when doing a repair. Some AC pumps have multiple speed settings so that the flow rate can be optimized for the system.

Figure 4.6: AC pump