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 person EGEE 102 Pisupati 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 T 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 auxiliary wood burner EGEE 102 Pisupati 13 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 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 EGEE 102 Pisupati 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 active EGEE 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 insolati on 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 in 1973 will cost nearly 160 year EGEE 102 Pisupati 26 Why Buy An Energy Efficient Refrigerator Uses the most electricity of