Energy Conserving AlternativesFormulasEstimate Annual EnergyEnergy SourcesAnnual CostingEnergy AlternativesEnergy AlternativesSlide 8Efficient Designs - OpportunitiesSummaryEnergy Conserving AlternativesHVAC 15aCNST 305 Environmental Systems 1Dr. BerrymanFormulasNote: These calculations do not include the cost of fan operation…add 10% for residential and 20% for commercial applicationsEstimate Annual EnergyEnergy SourcesAnnual CostingOffice – Example IOffice – Example IIGiven:•1500 hrs heating and cooling•Contributing lighting load (10 hrs) – 220,320 BH•Peak Heat Loss – 406,850 BH Peak Heat Gain – 630,172 BHEnergyAlternativesImproved Heat PumpsGiven:•Current Heat Pump – COP 2; SEER 9•New Heat Pump – COP 2.8; SEER 13•Annual Full Load heating hrs = 1500•Annual Full Load cooling hrs = 1500•Electricity $0.08 per kWh•Annual Heat Loss 389,680,000 BTU/yr•Annual Heat Gain 945,000,000 BTU/yrCost $10,0001st year return on investment: 47%Energy AlternativesLess Ventilation Given:•Original Design – 2,970 CFM winter2,400 summer•New Design – 2000 CFM winter/summer•Winter TD is 60oF; Summer CLTD 20oF•GD (grain difference) = 40•Annual Full Load heating hrs = 1600•Annual Full Load cooling hrs = 1400•Heat w/ an 75% efficient oil fired boiler•Oil $0.90 per gallon•Cool w/ SEER 8 electric chiller•Electricity $0.07 per kWhCost $2,5001st year return on investment: 53%Energy AlternativesMore Roof InsulationGiven:•Roof area 10,800 SF•Current U value = 0.05•New U value = 0.04•Winter TD is 60oF; Summer CLTD 36oF•Annual Full Load heating hrs = 1600•Annual Full Load cooling hrs = 1400•Heat w/ an 80% efficient gas furnace•Natural Gas $0.75 per therm•Cool w/ SEER 10 air conditioner•Electricity $0.09 per kWhCost $3,0001st year return on investment: 5.8%Efficient Designs - OpportunitiesSolar DesignsThermal MassEvaporationAir movementVentilation/InfiltrationMechanical SystemsZoningSummaryCalculated values for heat loss and gain may be used to estimate annual energy consumption and evaluate energy conserving alternatives.Indoor fan energy is not usually included in equipment efficiency ratings – Allow 10% residential and 20% for