EGEE 102 – Energy Conservation And Environmental Protection Appliances 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) EGEE 102 - Pisupati 2 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 EGEE 102 - Pisupati 3 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 EGEE 102 - Pisupati 4 Energy Guide • What is it ? • How to use it? • See class worksheet EGEE 102 - Pisupati 5 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 EGEE 102 - Pisupati person. 6 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 EGEE 102 - Pisupati 7 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 EGEE 102 - Pisupati 8 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. EGEE 102 - Pisupati 9 Electric vs. Gas • Electric water heaters are generally less expensive to install than gasfired 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. EGEE 102 - Pisupati 10 Energy Savings-Water Heaters • REDUCE WATER TEMPERATURE • Recall that heat flow is a function of DT • If T = 100°F, this is adequate for clothes washing and bathing. • T = 100°F may be too low for satisfactory operation of some dishwashers. (But some new models of dishwashers may supply auxiliary heat to the water.) EGEE 102 - Pisupati 11 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. EGEE 102 - Pisupati 12 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 13 EGEE 102 - Pisupati auxiliary wood burner 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! EGEE 102 - Pisupati 14 Operating Principle EGEE 102 - Pisupati 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 15 Type of Solar Water Heaters • Active Systems • Open-Loop Active Systems • Closed-Loop Active Systems • Passive Systems • Thermo-Siphon Systems Batch Heaters Heart of all solar heating systems: SOLAR COLECTOR!!! EGEE 102 - Pisupati 16 Solar Collectors • flat-plate, • evacuated-tube and • concentrating. EGEE 102 - Pisupati 17 Evacuated Tube Collector EGEE 102 - Pisupati 18 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?) EGEE 102 - Pisupati 19 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 activeEGEE or passive system? 102 - Pisupati 20 http://energyoutlet.com/res/waterheat/thermosyphon.gif Solar Heating • http://www.focussolar.com/index.ht m • http://www.focussolar.com/insolatio n.htm EGEE 102 - Pisupati 21 http://www.warmwater.com/eco.htm Refrigerator • Heat Mover • COP High Temperature Reservoir Work Low temperature Reservoir EGEE 102 - Pisupati 22 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 EGEE 102 - Pisupati 23 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. EGEE 102 - Pisupati Ammonia boils at -27F 24 Gas and Propane Refrigerator EGEE 102 - Pisupati 25 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 inEGEE 1973 will cost nearly 102 - Pisupati 26 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 EGEE 102 - Pisupati 27 (1993) standards. Side-by-side • Consumes more energy EGEE 102 - Pisupati 28 Top Mounted Type • More efficientconsumes less energy (13%) than side by side design EGEE 102 - Pisupati 29 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 EGEE 102 - Pisupati 30 EGEE 102New - Pisupati 31 Efficiency of an Average Refrigerator in the United States 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 EGEE 102 - Pisupati 32 Fridge of the Future • uses half as much energy as today's refrigeratorfreezers (RFs) and one-fifth as much as 1972 models: the 1 kilowatt-hour per day refrigerator. EGEE 102 - Pisupati http://www.ornl.gov/ORNL/BTC/adv-rf-tech.htm 33 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 EGEE 102 - Pisupati 34 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! EGEE 102 - Pisupati 35 • 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. EGEE 102 - Pisupati 36 • 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. EGEE 102 - Pisupati 37 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 EGEE 102 - Pisupati 38 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. EGEE 102 - Pisupati 39 How are they Energy Efficient? • Top loading horizontal-axis or tumbleaction 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. EGEE 102 - Pisupati 40 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 EGEE 102 - Pisupati 41 • washers are most efficient when they are fully loaded EGEE 102 - Pisupati 42 Dishwashers- Features • Child-safety locks • Construction materials • Cycles and temperature settings • Energy use • Controls • • • • Countdown timer Clean light Soil sensors Delay-start EGEE 102 - Pisupati 43 Types of Dishwashers • Built in Type • Portable dishwashers EGEE 102 - Pisupati 44 Operation Principle EGEE 102 - Pisupati 45 Energy Efficiency EGEE 102 - Pisupati 46 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 EGEE 102 - Pisupati 47 dishes.