Appliances

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Appliances
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Energy Consumption for Appliances (1997)

• 1192 Billion kWh total residential use
• 134 Billion kWh for refrigerators (12.14
  Billion)
• 549 Billion kWh for other appliances and lighting
  (48.44)

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Water Heater 288.00 Freezer/Frostless
136.80 Refrigerator 118.80 Waterbed
86.40 House Lighting 72.00 Clothes Dryer
59.76 Electric Range 45.36 Dishwasher
23.04
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Energy Guides

• EnergyGuide labels be placed on all new
  refrigerators, freezers, water heaters,
  dishwashers, clothes washers, room air
  conditioners, heat pumps, furnaces, and boilers.
• EnergyGuide labels show the estimated yearly
  electricity consumption to operate the product
  along with a scale for comparison among similar
  products

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Energy Guide

• What is it ?
• How to use it?
• See class worksheet

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Water Heaters

• Water heating is the third largest energy expense
  in your home. It typically accounts for about 14
  of your utility bill.
• A family of four, each showering for 5 minutes a
  day, uses 700 gallons of water a week this is
  enough for a 3-year supply of drinking water for
  one person.

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Heat Transfer

• Heat transfer is proportional to the temperature
  difference
• I.e. 120F 50 F (ambient temperature)
• Whether we use water or not heat is continuously
  flowing from the pipes to the room

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Energy Required to heat Water

• Q m x Cp x (Temperature Difference)
• M mass
• Cp Heat capacity (1 Btu/lb.F)
• 700 gal/wk x 8.3 lb/gal x (120-56)
• 371840 Btus
• 109 kWh/wk or 5667 kWh per year
• 385

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Storage Tank Water Heaters

• When you turn on a hot water faucet or use hot
  water in a dishwasher or clothes washer, water
  pipes draw hot water from the tank.

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Electric vs. Gas

• Electric water heaters are generally less
  expensive to install than gas-fired types because
  they don't require venting. But unless you live
  in a region where electricity is unusually
  affordable, an electric water heater can be
  significantly more expensive to operate.

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Energy Savings-Water Heaters

• REDUCE WATER TEMPERATURE
• Recall that heat flow is a function of DT
• If T 100F, this is adequate for clothes
  washing and bathing.
• T 100F may be too low for satisfactory
  operation of some dishwashers. (But some new
  models of dishwashers may supply auxiliary heat
  to the water.)

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Energy Saving-Water Heaters

• INSULATE WATER TANK (AND HOT WATER PIPES)
• Substantial saving in monthly energy bill by
  double layer of fiberglass insulation on water
  tank.
• The heat loss from the water tank contributes to
  space heating ?!
• Depends on design of home and location of water
  tank.

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Energy Savings - Water Heaters

• REDUCE CONSUMPTION
• Flow restricting heads for showers, sinks
• Shut off water heater at certain times
• AUXILIARY SOURCES OF HOT WATER
• Sometimes one can install a heat exchanger in
  flue of furnace or auxiliary wood burner

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On-Demand Water Heaters

• Hot water never runs out (low demand)
• Will not leak or rupture
• Reduce water heating costs as much as 20-30
• Heats only the water you use, at the temperature
  you desire Cold water is not required to regulate
  temperature
• Maintains its 99.5 efficiency throughout its
  lifespan
• Average lifespan is 20 years vs. a 10 year
  lifespan for a standard tank heater Scaling and
  rusting will not occur Hot water, forever!

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Operating Principle
One of the most powerful electric tankless water
heaters on the market, this 22KW, four element
water heater is configured for cold climates
where the incoming water temperature can drop
below 50 F.
http//www.e-tankless.com/products.php
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Type of Solar Water Heaters

• Active Systems
• Open-Loop Active Systems
• Closed-Loop Active Systems
• Passive Systems
• Thermo-Siphon SystemsBatch Heaters

Heart of all solar heating systems SOLAR
COLECTOR!!!
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Solar Collectors

• flat-plate,
• evacuated-tube and
• concentrating.

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Evacuated Tube Collector
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Factors for sizing a Solar Collector

• Your local annual average solar insolation level.
• Average daily hot water usage volume
• Daily hot water usage pattern (mostly mornings,
  mostly evenings)
• Average mains water temperature
• Annually/daily shade patterns
• Angle/direction of installation (a less than
  ideal angle will reduce efficiency)
• Installation site (Do you have enough room for 2
  collectors?)

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Solar Water Heater

• A thermosyphon-type solar water heater has an
  insulated water storage tank mounted above flat
  plate solar collectors
• The collectors transfer heat from the sun to an
  antifreeze collector fluid.
• Whenever hot water is used, solar heated water is
  drawn from the storage tank into the electric
  water heater

Is this active or passive system?
http//energyoutlet.com/res/waterheat/thermosyphon
.gif
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Solar Heating

• http//www.focus-solar.com/index.htm
• http//www.focus-solar.com/insolation.htm

http//www.warmwater.com/eco.htm
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Refrigerator

• Heat Mover
• COP

High Temperature Reservoir
Work
Low temperature Reservoir
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Components of a Refrigerator

• There are five basic parts to any refrigerator
• Compressor
• Heat-exchanging pipes - serpentine or coiled set
  of pipes outside the unit
• Expansion valve
• Heat-exchanging pipes - serpentine or coiled set
  of pipes inside the unit
• Refrigerant - liquid that evaporates inside the
  refrigerator to create the cold temperatures

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How a Refrigerator Works?

• The compressor compresses the ammonia gas. The
  compressed gas heats up as it is pressurized .
• The coils on the back of the refrigerator let the
  hot ammonia gas dissipate its heat. The ammonia
  gas condenses into ammonia liquid at high
  pressure.
• The high-pressure ammonia liquid flows through
  the expansion valve.
• The liquid ammonia immediately boils and
  vaporizes (light blue), its temperature dropping
  to -27 F. This makes the inside of the
  refrigerator cold.
• The cold ammonia gas is sucked up by the
  compressor, and the cycle repeats.

Ammonia boils at -27F
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Gas and Propane Refrigerator
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Energy Efficiency

• Federal efficiency standards took effect in 1993,
  requiring new refrigerators to be more efficient
  than ever before.
• The energy bill for a typical new refrigerator
  with automatic defrost and top-mounted freezer
  will be about 55/year, whereas a typical model
  sold in 1973 will cost nearly 160/year.

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Why Buy An Energy Efficient Refrigerator?

• Uses the most electricity of all your kitchen
  appliances and accounts for as much as 15 percent
  of a home's total energy usage.
• A typical refrigerator costs about 1,140 to
  operate over its lifetime.
• Refrigerators made to meet the latest DOE
  standards (which will take effect in 2001) will
  cut consumers' energy costs by 30 percent
  compared to the previous (1993) standards.

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Side-by-side

• Consumes more energy

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Top Mounted Type

• More efficient- consumes less energy (13) than
  side by side design

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Efficiency of a Refrigerator

• The efficiency of a refrigerator is expressed in
  "volume cooled per unit electric energy per day."
  Volume is measured in cubic feet and electrical
  energy is measured in kilowatthours

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Efficiency of an Average New Refrigerator in the
United States
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Technology improvements

• addition of vacuum insulation panels around
  freezer section to reduce heat transfer,
• addition of polyurethane foam to the doors to
  double insulation thickness,
• replacement of AC motors with more efficient DC
  motors, and
• replacement of automatic defrost control with an
  adaptive defrost that operates only when needed

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Fridge of the Future

• uses half as much energy as today's
  refrigerator-freezers (RFs) and one-fifth as much
  as 1972 models the 1 kilowatt-hour per day
  refrigerator.

http//www.ornl.gov/ORNL/BTC/adv-rf-tech.htm
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Energy Savings

• Cuts power consumption to 0.93 kWh/day, a
  performance that exceeds the 2001 energy standard
  and that would save 6.5 billion annually if all
  the 125 million RFs in the U.S. operated as
  efficiently

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Good Operating Practices

• Don't put the refrigerator near a heat source -
  an oven, the dishwasher or direct sunlight from a
  window.
• Make sure air can circulate around the condenser
  coils. Leave a space between the wall or
  cabinets.
• Keep your refrigerator's coils clean. Brushing or
  vacuuming the coils can improve efficiency by as
  much as 30 percent.
• Check door seals to make sure they are airtight.
  To test them, close the door on a dollar bill and
  try to pull it out. If the dollar slides out
  easily, kiss that dollar away because you're
  wasting energy and money by letting cold air leak
  out!

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• Check the temperature - a fridge that is 10
  degrees colder than necessary can use 25 percent
  more energy. Refrigerators should be kept between
  35 and 38 degrees - freezers at 0 degrees
  Fahrenheit.A full refrigerator retains cold
  better than an empty one.
• Open the door as little as possible. Get in and
  out quickly.

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• Regularly defrost manual-defrost models. Frost
  buildup increases the amount of energy needed to
  keep the motor running.
• Allow hot foods to cool before refrigerating or
  freezing.
• Get rid of that older, energy-hogging second
  refrigerator in your garage! One large
  refrigerator is cheaper to run than two smaller
  ones.

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Clothes Washers

• There are two designs
• top-loading
• front-loading.
• A typical household does nearly 400 loads of
  laundry per year, using about 40 gallons of water
  per full load with a conventional washer

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Why Energy Efficient Models?

• You could save as much as 7,000 gallons of water
  per year.
• You are saving all the energy that would have
  been needed to heat that water.
• This adds up to savings for you and a big boost
  for the environment.

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How are they Energy Efficient?

• Top loading horizontal-axis or tumble-action
  machines repeatedly lift and drop clothes,
  instead of moving clothes around a central axis.
• Top-loading washers use sensor technology to
  closely control the incoming water temperature.
  To reduce water consumption, they spray clothes
  with repeated high-pressure rinses to remove soap
  residues rather than soaking them in a full tub
  of rinse water.

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Energy Star Washers

• A full-size ENERGY STAR clothes washer uses
  20-25 gallons per load
• Nearly 50 percent less water and 30-40 less
  energy used per load
• Washer design causes less wear and tear on
  clothes
• Bulky items such as blankets fit easily in the
  super capacity basket.
• Better water extraction means less dryer time,
  for further energy savings

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• washers are most efficient when they are fully
  loaded

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Dishwashers- Features

• Child-safety locks
• Construction materials
• Cycles and temperature settings
• Energy use
• Controls
• Countdown timer
• Clean light
• Soil sensors
• Delay-start

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Types of Dishwashers

• Built in Type
• Portable dishwashers

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Operation Principle
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Energy Efficiency
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Dish Washers

• ENERGY STAR dishwashers save electricity and hot
  water by using both improved technology for the
  primary wash cycle, and by using less hot water
  to clean.
• Construction includes energy efficient motors,
  and other advanced technology such as sensors
  that determine the length of the washing cycle
  and the temperature of the water necessary to
  clean the dishes.