GNSC 1150 1st EditionExam# 2 Study Guide Lectures: 12 - 22Lecture 12(February 11)Heat & WorkResidential Energy Use: Heating8% Cooling and Ventilation20% Hot water41% Heating and Air31% Appliances and LightingBuildings account for 70% of electricity use in the U.S.Thermal Energy, Temperature, and Heat Thermal Energy – The sum of all the energies of each particle in particular object Temperature– proportional to the average kinetic energy of one particle in a particular object Heat– Thermal energy in transit due to a temperature difference. Objects do NOT contain heat. Heat is a transferof energy, just like work is a transfer of energy.60% of household energyconsumptionMechanical Equivalence of Heat- James Joule concluded that heat was a form of energy, and that work and heat could be transformed into each other. - The temperature of water will rise with work done or heat added.1 calorie=4.186 J is the mechanical equivalent of heat.Laws of Thermodynamics 1 st Law of Thermodynamics Change in energy=net heat added to a system + work done on a systemChange in energy= net heat added to a system-work done by a systemThese are equivalent and are statements of the law of conservation of energy2 nd Law of Thermodynamics Entropy- a measure of the disorder of a systemThe entropyof an isolated system can only increase or stay the same but never decrease.-Important consequences:1. Heat can flow spontaneously only from a hot source to a cold sink.2. No heat engine can be constructed in which heat from a hot source is converted entirely to work. Some heat has to be discharged to a sink at a lower temperature.Allowed by 1st law, but not by 2nd law-a block in thermal equilibrium with the table cannot absorb thermal energy from the table and convert it to work.Heat Transfer PrinciplesConduction- Transfer of thermal energy through the collision of atoms and molecules.- All materials have a property called thermal conductivity- Larger thermal conductivities are better at conducting heat energy-metals have high thermal conductivities.Convection- Transfer of thermal energy by the flow of a fluid (liquid or gas)- Warmer fluids rise.- As the fluid rises, it cools and begins to sink.Radiation- Heat transferred by the absorption or emission of light.- All objects with a temperature emit light. Objects at room temperature emit in the infrared range.Lecture 13(February 16)-Snow DayLecture 14(February 18)-Reading Assessment TestSaving Energy in the HomeHeat Loss by ConductionHigher R value=better insulatorR values add to each other when layered. Ie.Walls.Lecture 15(February 23)Heat Loss by ConvectionWind- Increases heat loss by convection- Increases infiltration- Planting trees can help reduce wind velocity 35% of heat is lost from windowsLecture 16(February 25)-Snow DayLecture 17(March 2)Fossil Fuels (Oil, Natural Gas, and Coal)Reserves: resources that are known to exist and can be extracted at current prices with current technologyOil-made of decaying algae and plankton which produce methane. The left over organic material is buried and forms petroleum with pressure and temperature. Petroleum consists of liquid and gaseous hydrocarbons. Petroleum is refined and separated into different kinds of oil and products.Petroleum is trapped under rock and must be drilled to extract. The more petroleum removed from a well, the more difficult extraction becomes.Natural GasComes from plant matter decaying in the absence of oxygen.Consists primarily of methane.Always found with petroleum, but is also found alone and it can be harvested from waste facilitiesCoalComes from higher plants which contain large amounts of lignin which are compressed with sufficient heat and pressure.Forms in once swampy areas.World’s most abundant fuel. 80% of the U.S. fossil fuel reserves.Coal is extracted from underground and strip mines.Lecture 18(March 4)-Reading Assessment TestHeat Loss and Gain by RadiationLow-e coatings on windows block infrared (IR) radiation.South-facing windows can actually help heat your house in the winter, because the sun is always low in the sky.Lecture 19(March 9)Group Assignment 5Two examples of solutions to heat lossRadiation1. Check to see if you have a large number of south facing windows. If you do, make sure they are uncovered during the day to gain thermal energy.2. Apply e-coating to windows to keep infrared light inside the house.Conduction1. Use double or triple-paned windows.2. Use a high R-value insulation in the ceiling.3. Set thermostat to a lower temperature during the winterConvection1. Use weather stripping on doors and windows, and make sure door and window frames are caulked.2. Install drapes that reach the floor and a valance on top to reduce convection.3. Set thermostat lower in winder.Lecture 20(March 11)Air pollution70,000 people per year die from air pollutionTemperature inversion happens when a warm layer of air lies above a colder part, in effect putting a lid over the region and therefore stopping atmospheric dispersion of pollutants.ppM=Parts per millionCarbon Monoxide Produced in automobile engines by the incomplete combustion of carbon in gasoline fuel.Monoxide is toxic to humans because it will pass through the lungs into the blood-stream and bind to the hemoglobin, thus preventing blood from carrying oxygen to bodycellsSulfur OxideProduced from the burning of fossil fuels and the oxidation of sulfurWhen inhaled can lead to damage in the upper respiratory tract, damage to lung tissue, and aggravation of lung disease. Caused deaths in Pennsylvania and EnglandCauses acid rainNitrogen OxidesBurning causes nitrogen oxides which lead to ozone, a major part of smog.Ozone irritates the lungs and can aggravate asthma.Ground-level ozone production depends on Nitrogen Dioxide, light, plus Volatile Organic Compounds.Ways to control nitrogen oxides:Emissions testing on vehiclesBurning permitsCatalytic convertersParticulatesSmall particles between .01 and 50 micronsSources: burning coal, wood, and trash. Pollen, dust, ashAffect breathing and can aggravate existing health conditions.- Sometimes indoor pollution can be greater than outdoor if not circulated with fresh air.- Newer homes tend to have less infiltration to be more energy efficientThe EPA (Environmental Protection Agency) is responsible for imposing restrictions on pollutant emissions.Lecture 20(March 16)Greenhouse Effect: Light