Transcript Ch. 16 Sec. 3

Ch. 16 Sec. 3
Using Heat
Heating Systems
• Most homes & public
buildings contain
some kind of heating
system.
• In the simplest and
oldest heating system,
wood or coal is
burned in a stove.
Forced-Air Systems
• Use fans to circulate warm air: Convection
• Filtered and cleaned as it passes through out
the system
Radiator Systems
• A radiator is a closed metal container that
contains hot water or steam.
• The thermal energy contained in the hot water
or steam is transferred to the air surrounding the
radiator by conduction.
• This warm air then moves through the room by
convection.
Electric Systems
• An electric heating system has no central
furnace – Space heater
• Instead, electrically heated coils placed in
floors and in walls heat the surrounding air
by conduction.
• Heat is then distributed through the room
by convection.
Solar Heating Systems
Passive Solar Heating
Active Solar Heating
• Absorb radiant energy • use solar collectors
that absorb radiant
from Sun.
energy from the Sun.
Heat Engines
• A device that converts heat into work is a heat
engine.
• A car’s engine converts the chemical energy in
gasoline into heat.
• The engine then
transforms some
of the thermal
energy into work
by rotating the
car’s wheels.
Internal Combustion Engines
• Four-stroke cycle engine
Intake
Stroke
Compression
Stroke
Power
Stroke
Exhaust
Stroke
Heat Movers
• Device that removes thermal energy from
one place and transfers it to another place
at a different temp.
• Ex. Refrigerator, air
conditioners, de-
humidifiers, heat
pumps.