A RACE FOR THE SUN

Lauren StencelChapter 16

Key words Passive solar heating system Active solar heating system British Thermal Unit (BTU)

Joule Energy Efficiency

A Passive Solar Heating System A house in the Northern hemisphere with this system have

large south-facing windows. Sunlight will shine onto a thermal mass through the

windows. The thermal mass will release stored energy during the night

An Active Solar Heating System Uses pumps to move a working fluid

from a solar collector to the interior of the structure

Energy Cannot be destroyed But can be stored or transferred And measured in a system

A British Thermal Unit (BTU) Is the amount of energy it takes to raise

the temperature of one pound of water by on degree Fahrenheit.

How many BTU does this room need to heat?

A Joule Is the metric unit for energy. It takes

about 4.186 Joules (or 1 calorie) to raise the temperature of one gram of water by one degree Celsius.

Energy efficiency Is a ratio of the useful energy outputs to

the energy inputs of a system. If all of the inputs of a heating system

were used to heat the house, then this ratio would be 1, or 100%.

Who is Lauren Stencel?A.EnvironmentalistB.Solar decathleteC.ArchitectD.Environmental engineer

What are the two different sets of constraints that Lauren’s team must consider when designing the house?

A. Money and TimeB. Building codes and Building zonesC. Economical and political problemsD. The house must function independently

in its permanent location

Where should a thermal mass of a structure be located in order for passive solar heating to work well?

A. Inside the houseB. BasementC. On the roofD. Outside the house

What’s a passive solar heating system? Why is it called “passive”? A passive solar heating system uses the

energy of sunlight to warm a home. Passive solar heating system involve

large –south-facing windows so that the sun can shine onto a thermal mass to warm up the house.

The building should be sited so that one wall faces south to be energy-efficient. Why? The attribute will allow for passive solar

heating, solar day lighting, and will provide good surfaces for attaching solar panels.

What else can you do to make your building more energy-efficient? The building should be designed with

large, south-facing windows and a thermal mass on the interior of the building. (Why?)

Windows and doors should be designed to leak as little thermal energy to the environment as possible. (Why?)

Window coverings should be designed so that sunlight coming into the building can be reduced in summer months. (Why?)

What else? A good insulator should be chosen for

walls and roof. (Why?) The heating system should include a

thermostat in every room. (Why?) Pipes in the heating system should be

insulated as well. (Why?)

Which is a better insulator, wood or cellulose insulation? How do you know? Cellulose insulation is a better insulator

because R-value is higher.