太阳能热水器分类和比较(英文).doc

/wiki/Solar_water_heating / Three types of solar collectors： 1、Flat-plate collector平板式 2、Integral collector-storage systems(ICS)不适合冰冻环境 3.、Evacuated-tube solar collectors真空管式 There are two types of active solar water heating systems： 1、Direct circulation systems泵循环式 2、Indirect circulation systems适合冰冻环境 Protect against freezing in colder climates. Some solar systems are appropriate for freezing climates, while others are not. As a general rule, if there is a good chance that temperatures will fall below 42°F, choose either a closed-loop system with antifreeze as the heat transfer fluid, or a system that automatically drains back when temperatures fall too low for comfort. Steer clear of batch systems if you live in a climate with distinct winters. Learn more about freeze protection Estimate the capacity youll need. Use the gallon capacity of your current water heater as a starting point. You can find your current water heaters capacity or volume on its nameplate or yellow Energy Guide sticker. This should help you discuss the sizing of your solar system with contractors. If you have recently added or are planning to add more occupants to your household or a new shower, faucet, dishwasher or washer that will be in frequent use, take that into account in your discussions. Collector Types Batch collectors, also called Integrated Collector-Storage (ICS) systems, heat water in dark tanks or tubes within an insulated box, storing water until drawn. Water can remain in the collector for long periods of time if household demand is low, making it very hot. A tempering valve is your protection from scalding at the tap. The tempering valve mixes in cold water to decrease the waters temperature before its delivered to the tap. Batch collectors are incompatible with closed-loop circulation systems. Thus, they are generally not recommended for cold climates. Flat-plate collectors typically consist of copper tubes fitted to flat absorber plates. The most common configuration is a s