Transcript Heating without Devices

Heating with Devices
Solar Heating
Passive
Heating without Mechanical
Components
Active
Heating with Mechanical
Components
• Reduce Heat Loss
• Increase Heat Gain From Sun
• Consists of a Collector, a Heat
Storage Unit, and a Heat
Distribution System
Active Solar Heating
• Water in collector traps
solar energy
• Travels to storage and
distribution units
Heat Collector
Solar Heating – Is It Practical?
• In the prairies, can meet ~75%
of heating needs
• Backup system for other ~25%
Solar Arrays
• Solar cells arranged in panels
• Capture energy and store it in low voltage
batteries
• Remote weather stations powered this way.
Why?
Pros and Cons
Pros
• Not limited; renewable
• Solar energy does not create
harmful by-products
Cons
• Expensive to set up
• Disposal of solar cells is
environmental concern
Heating Technologies
Thermostat
Thermo = heat
Stat = maintain/keep the same
Used in houses and in electrical
devices to keep temperature
constant
How Does a Thermostat Work?
Bimetallic Strip
Bi = 2
2 Metal Strip
Bends to open and close a circuit
Local and Central Heating Systems
Two main types of heating systems
Local heating system provides heat to one room or small area
Fireplace, stove, space heater
Central heating system provides heat from a single, central source
Heats many areas (Whole building)
Forced-air and Hot-water heating
Forced-Air Heating
• Air heated by furnace
• Travels through ducts to
registers
• Blower helps pull
returning air into furnace
• See textbook Fig. 3.11 pg
231
Hot-Water Heating
• Water heated by furnace/boiler
• Pump forces water through pipes
to metal radiators
• Radiators heat room
• As water cools, it returns to boiler
Keeping Cool
Keeping Cool
Refrigerant = liquid/gas used in
cooling system
See
http://www.realsimple.com/foo
d-recipes/toolsproducts/appliances/how-doesrefrigerator-work