托福听力词汇以及相关背景知识的积累，是一个相当漫长的过程，需要考生在平时的生活中多总结，多记忆。小编为大家整理了托福听力环境学背景知识：被动加热系统和主动加热系统，希望对各位同学的托福听力备考有所帮助：

Introduction：

passive and active heating systems

被动式太阳房完全依靠太阳能采暖,不用其他辅助能源。主动式太阳房用水泵或风机把经太阳能加热过的水或空气送入室内,达到采暖的目的。

Background information：

Passive solar technologies use sunlightwithout active mechanical systems (as contrasted to active solar). Suchtechnologies convert sunlight into usable heat (in water, air, and thermalmass), cause air-movement for ventilating, or future use, with little use ofother energy sources. A common example is a solarium on the equator-side of abuilding.

Solar hot water systems use pumps or fansto circulate fluid (often a mixture of water and glycol to prevent freezingduring winter periods) or air, through solar collectors, and are thereforeclassified under active solar technology.

Some of the basic benefits of activesystems is that controls (usually electrical) can be used to maximize theireffectiveness. For example a passive solar thermal array which does not rely onpumps and sensors will only start circulating when a certain amount of internalenergy has built up in the system. Using sensors and pumps, a relatively smallamount of energy (i.e. that used to power a pump and controller) can harvest afar larger amount of available thermal energy by switching on as soon as auseful temperature differential becomes present. Controls also allow a greatervariety of choices for utilizing the energy that becomes available. For examplea solar thermal array could heat a swimming pool on a relatively cool morningwhere heating a domestic hot water cylinder was impractical due to thedifferent stored water temperatures. Later in the day as the temperature risesthe controls could be used to switch the solar heated water over to thecylinder instead.

Knowledge points：

1. 被动加热系统不依靠机械装置收集太阳能。

2. 主动加热系统利用泵或者风扇循环水或者空气。主动加热系统的好处是可以比较大化的利用太阳能。

Vocabulary prediction：

Plumb 铅垂

Tank 水箱

Mechanical 机械的

Concrete 混领土

Test Point – TPO12L4

Yep, greenhouses where plants are kept warmand provided with sunlight because the walls of the building are made entirelyof glass. But we do also have more complex systems that are used for spaceheating and they fall into two categories, passive and active heating systems.Passive systems take advantage of the location or design of a house. Forexample, solar energy is gathered through large glass panels facing the sun.The heat is then stored in water-filled tanks or concrete. No mechanicaldevices are used in passive heating systems. They operate with little or nomechanical assistance. With active systems, on the other hand, you collect thesolar energy at one location, and then you use pumps and fans to move heat fromthe collectors through a plumbing system to a tank, where can be used to heat ahome or to just provide hot water.

Student B

Excuse me professor, but I’ve got to ask,how can solar energy work at night or on cloudy days?

Professor

That’s...Well...that is a really goodquestion. As a matter of facts, science is still working on it, trying to findways of enhancing energy storage techniques so that coming of night or cloudydays really wouldn’t matter. That is the biggest drawback to solar energy. Theproblem of what do you do in cases where the sun’s light is weak or virtuallynon-present. So the storage of solar energy, lots of solar energy, is a really importantaspect.

Knowledge points

1.空间加热有两类:被动加热系统和主动加热系统。

2.被动加热系统利用住宅位置和场所。比如,太阳能是通过面对太阳的大的玻璃板收集的。热量然后被储存在充满水的水箱或者混凝土中。被动加热系统不使用机械装置。

3.主动加热系统在一个位置收集太阳能,然后使用泵和风扇将热量用管道系统从收集器移动到水箱。