PE Exam Review

Environmental Systemsand Facilities PlanningDoug Overhults University of KentuckyBiosystems & Agricultural Engineering

University of KentuckyCollege of AgricultureUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering1Topic OutlinePsychrometrics ReviewEnergy Balances/LoadsLatent heat Sensible heatSolar loadsInsulation Requirements

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering2Topic OutlineVentilation SystemsRate requirementsSystem requirementsMoisture Control StandardsAir Quality StandardsHumansAnimalsPlants and ProduceUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering3Psychrometrics VariablesUsing the Psychrometric ChartPsychrometric Processes

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering4Psychrometric ChartDry Bulb Temperature Scale (axis)Humidity Scaleor axisState PointUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering5Psychrometric Chart(temperatures + relative humidity)Dry Bulb Temperature ScaleHumidity Scaledew-pointwet bulbdry bulbExample:70 oF dry bulb55 oF dew-point61 oF wet-bulb60 % rh

relative humidityUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering6Psychrometric ProcessesHeating, cooling, humidifying, dehumidifying air-water vapor mixtures

Five basic processes to knowHeat or Cool (horizontal line)Humidify or De-humidify (vertical line)Evaporative cooling (constant wet-bulb line)University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering7Heating: dry bulb increaseDry Bulb Temperature ScaleHumidity Scaleending state pointstarting state pointHorizontal line means no change in dew-point or humidity ratioUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering8Humidification: dew-point increaseDry Bulb Temperature ScaleHumidity Scalestart stateend stateVertical line means no change in dry bulb temperatureRH goes up!University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering9Evaporation: wet bulb increaseDry Bulb Temperature ScaleHumidity Scalestart stateend stateIncrease in vertical scale: humidifiedDecrease in horizontal scale: cooledConstant wet bulb lineAdiabatic process no heat gained or lost (evaporative cooling)University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering10Air DensityDry Bulb Temperature ScaleHumidity ScaleWet bulb lineHumid Volume, 1/ft3/lb daUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering11ReviewName three temperature variablesName three measures of humidityName the two main axes of the psychrometric chartName the line between fog and moist airHeating or Cooling follow constant line of ?Humidify/Dehumidify follow constant line of ?University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering12Energy and Mass Balances University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering13Energy and Mass Balances Heat Gain and Loss Latent and Sensible Heat ProductionMechanical Energy LoadsSolar LoadMoisture Balance

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering14Heat Gain and LossOccupantsLightingEquipmentVentilationBuilding EnvelopeRoof, walls, floor, windowsInfiltration (consider under ventilation)

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering15Heat LoadsOccupant (animals, people)Sensible load (e.g. Btuh/person)Latent load ()Lighting, W/m2Appliance W/m2Ventilation air (cfm/person or animal)Equipment (e.g. Btuh for given items)

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering16Ventilation Temperature control Moisture controlContaminants (CO2, dust, NH3) controlEnergy use

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering17Latent and Sensible Heat Production Example from ASAE Standard EP270.5:

Table 1. Moisture Production, Sensible Heat Loss, and Total Heat Loss

Cattle Bldg. T MPSHL THL500 kg 21C 1.3 gH2O/kg-h 1.1 W/kg 2.0 W/kgUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering18Sensible Energy Balance Leads to Ventilation for Temperature Control:

qs + qso + qm + qh = UA(ti-to) + FP(ti-to) + cpV (ti-to) Heat inputs = envelope + floor + ventilationqs sensible heat qso solar heat gainqm mechanical heat sources qh supplemental heatU building heat transfer coeff.P floor perimeterF perimeter heat loss factor cp specific heat of airV ventilation rate density of airUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering19Sensible Energy Balance Leads to Ventilation for Temperature Control. Rearranging:

V = [ qs - ( UA+ FP)(ti-to)] / 0.24 (ti-to)60 V cfm (equation for English units)University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering20Mass Balance=+mpMaterial producedmviMaterial input ratemvomaterial output rateMoisture, CO2, and other materials use balance equations.University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering21Moisture Balance=mairVentilation rateMwaterMoisture to be removedExample balance for moisture control removal rate.(Wi-Wo)Humidity ratio difference/Q = (V / 60) x [ Wr / (Wi-Wo) ]Q - cfm V ft3/lbda Wr lbm / hr W lbm / lbdaUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering22Find the minimum winter ventilation rate to maintain60% relative humidity inside a swine nursery that hasa capacity of 800 pigs weighing 10 pounds. Insidetemperature is 85 degrees.Moisture Balance ASABE D270.5

Nursery Pigs Bldg. T MPSHL THL4 - 6 kg 29C 1.7 gH2O/kg-h 2.2 W/kg 3.3 W/kgUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering23Find the minimum winter ventilation rate to maintain60% relative humidity inside a swine nursery that hasa capacity of 800 pigs weighing 10 pounds. Insidetemperature is 85 degrees.Find moisture production dataASABE Standards (EP270.5)Wr = 0.017 lb/hr/pigGet psychrometric data from chartW0 = 0.0005Wi = 0.0154V = 14.1Plug into equation & solveQ = (14.1/60) x [(.017 x 800) / (.0154 - .0005)]Q = 214 cfmUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering24Find the ventilation rate required to prevent theammonia concentration inside a poultry layer barnfrom rising above 20 ppm. Ammonia production in the barn is estimated to be 21.6 cubic feet per hour. Ammonia concentration in theambient air is 2 ppm.NH3 Balance University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering25NH3 SolutionUse volumetric form of mass balance equationVp + Vi = VoVp + Qv[NH3]i = Qv[NH3]oSolve for QvQv = Vp / { [NH3]o - [NH3]i }Get quantities in consistent unitsVp = (21.6 ft3/hr / 60 min/hr) = 0.36 ft3/minPlug into equation & solveQ = 0.36 / (.000020 - .000002)]Q = 0.36 / .000018Q = 20,000 cfmUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering26What is the ventilation rate for a swine finishing barn that will limit the design temperature rise inside the house to 4 degrees (F) above the ambient temperature? The barn capacity is 1000 pigs at 220 pounds and the inside temperature is approximately 85 F. The overall heat transfer coefficient for the barn is 1200 Btu/hr F.Energy BalanceUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering27What is the ventilation rate for a swine finishing barn that will limit the design temperature rise inside the house to 4 degrees (F) above the ambient temperature? The barn capacity is 1000 pigs at 220 pounds and the inside temperature is approximately 85 F. The overall heat transfer coefficient is 1200 Btu/hr F.Find heat production dataASABE Standards (EP270.5)q = 0.49 W/kg (sensible heat)Convert units & calculate total heat loadq = 0.49 W/kg x 100 kg/pig x 1000 pigs = 49,000 W x 3.412 Btu/hr W = 167,188 Btu/hrDensity of Air = 0.075 lb/ft3Specific heat of air = 0.24 Btu/lb Fti to = 4 FUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering28Continuation . . . ventilation rate for a swine finishing barn that will limit the design temperature rise inside the house to 4 degrees (F) above the ambient temperatureBasic equation

Neglect floor heat loss or gain

Plug into equation & solveV = [167,188 - (1200 x 4)] / [(0.24 x 0.075) x 4 x 60]V = 37,590 cfmV = [ qs - ( UA+ FP)(ti-to)] / 0.24 (ti-to)60 University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering29Fan Operating Cost=WPower input, WattsVVentilation volumetric flow ratecfm / WattFan Test EfficiencyElectrical Power CostUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering30Calculate Operating CostsDesign Ventilation Rate 169,700 cfmFan ChoicesBrand A 21,300 cfm @ 19.8 cfm/wattBrand B 22, 100 cfm @ 16.2 cfm/wattFans operate 4000 hours per yearElectricity cost - $0.10 per kWhCalculate annual operating cost differenceUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering31Calculate Operating Costs8 fans required for brand A or BUse EP 566, Section 6.2Annual cost is for all 8 fans

Watts * hrs * $/kWh * kWh/Wh = $University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering32References Env. SystemsAlbright, L.D. 1990. Environment Control for Animals and Plants. ASAEHellickson, M.A. and J.N. Walker. 1983. Ventilation of Agricultural Structures. ASAE

ASHRAE Handbook of Fundamentals. 2009.

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering33Reference

MWPS - 32Contains ASABE heat & moistureproduction data & example problemsMidwest Plan ServiceIowa State UniversityAmes, IAUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering34ReferenceMWPS - 1Broad reference to cover agriculturalfacilities, structures, & environmental controlMidwest Plan ServiceIowa State UniversityAmes, IAwww.mwps.orgSTRUCTURES andENVIRONMENTHANDBOOKUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering35Useful References Env SysMidWest Plan Service. 1990. MWPS-32, Mechanical Ventilation Systems for Livestock Housing.

Greenhouse Engineering (NRAES 33) ISBN 0-935817-57-3http://palspublishing.cals.cornell.edu/nra_order.taf

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering36References ASAE StandardsEP270.5 Ventilation systems for poultry and livestock

EP282.2 Emergency ventilation and care of animals

EP406.4 Heating, ventilating cooling greenhouses

EP460 Commercial Greenhouse Design and Layout

EP475.1 Storages for bulk, fall-crop, irish potatoes

EP566 Selection of energy efficient ventilation fans

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering37FACILITIES Manure Management Example University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering38Manure Management FacilitiesAnimal Manure ProductionNutrient ProductionDesign Storage VolumesLagoon Minimum Design VolumeReferencesASAE EP 384.2, 393.3, 403.3, 470NRCS Ag. Waste Field HandbookUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering39Size a Manure Storage1 year storageAbove ground 90 dia. tank uncovered 2500 hd capacity grow/finish pigsBuilding turns over 2.7 times/yrManure production 20 ft3/finished animalNet annual rainfall = 14 inches25 yr. 24 hr storm = 5.8 inchesUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering40Size a Manure StorageUse EP 393, sections 5.1 & 5.3Total volume has 5 componentsManure, Net rainfall, 25 yr-24 hr stormIncomplete removal, Freeboard for agitation

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering41Size a Manure StorageManure Depth = 21.22 ft.Net rain = 1.17 ft25 yr-24 hr storm = 0.48 ftIncomplete removal = 0.67 ftFreeboard = 1 ftTotal Tank Depth = 24.54 ft.University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering42References - FaciltiesAgricultural Wiring Handbook, 15th edition, Rural Electricity Resource CouncilFarm Buildings Wiring Handbook, MWPS-28 (now updated to 2005 code) Equipotential Plane in Livestock Containment Areas ASAE, EP473.2 Designing Facilities for Pesticide and Fertilizer Containment, MWPS-37 On-Farm Agrichemical Handling Facilities, NRAES-78 Farm and Home Concrete Handbook, MWPS-35Farmstead Planning Handbook, MWPS-2 (download only)

University of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering43References ASAE StandardsD384.2 Manure Production and Characteristics

EP393.3 Manure Storages

EP403.4 Design of Anaerobic Lagoons for Animal Waste Management

EP470.1 Manure Storage Safety

S607 Ventilating Manure Storages to Reduce Entry RisksUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering44Thank You

and

Best Wishes for Success on Your PE Exam ! !

University of KentuckyCollege of AgricultureBiosystems & Agricultural EngineeringUniversity of KentuckyCollege of AgricultureBiosystems & Agricultural Engineering45