It's Hot In Here

Programable thermostats and other technologies have provided many ways to conserve energy and save money. A recirculating hot water system (Figure 3.41, p. 252) saves energy and produces instant hot water at all times.

It's Cold In Here

Refridgerators and air conditioners are thermal energy movers. A thermal energy mover is a device that transfers thermal energy from one location to another at a different temperature. The operation of these devices require refrigerants (liquids that evaporate easily at low temperatures) to remove thermal energy from food. As the refrigerant evaporates, it absorbs the thermal energy from the food so it cools down. This warmed gas is then compressed and releases the thermal energy into the room.

Danger: Thermal Energy

Some harmful effects of thermal energy are:
burning ourselves on a hot utensil (us)
forest fires (our envirnment)
burning houses (our belongings)
Storage and use of fossil fuels can pose a forest fire risk, but also can pollute the environment, by leaking into the groundwater and soil.

By-Products of Thermal Energy Use

Not all the dangers of using thermal energy are as obvious as the ones already discussed. One of the products (carbon dioxide) that is released from the burning of fossil fuels is a greenhouse gas, which traps heat energy in our atmosphere and leads to global warming.

Sulfur-dioxide is released when coal and natural gas are burned. This gas is an irritant to the eyes, nose and throat.

Carbon monoxide is produced when a fire burns without enough oxygen. It is clearless, odourless and very lethal. It hinders the brain's reasoning ability and can kill you.

Smoke detectors and carbon monoxide detectors should be installed in every building to protect the people from being overcome by these lethal gases.

Topic Review p. 256
Wrap-Up (Topics 7 - 8) p. 257
UNIT REVIEW pgs. 262 - 265