Presentation Title

Energy Management Opportunitiesin Heating, Ventilation and Air Conditioning (HVAC)

#1Your panelistsBenefits, Technologies & Services: Mike Carter and Mark Farrell, Energy Engineers

#2Why is HVAC important?ProductivityComfortExpense

Source: www.bcs.orgSource: www.doe.gov

#3ContentsBasicsCoolingChillersPackaged RooftopsPackaged Terminal Air Conditioners (PTACs)Geothermal Heat PumpsHeatingElectric/Electrode BoilersSpace Heaters AccessoriesEnergy-Savings TipsBusiness Solutions ToolkitRebates/Incentives

Source: NREL#4HVAC basicsPower versus EnergyKilowatt (kW), or demand, is a measure of power, similar to the speedometer of your car that records the rate at which miles are traveled.A bigger engine is required to travel at a faster rate.Kilowatt-hour (kWh) is a measure of energyconsumption, similar to the odometer on your car which measures the miles traveled.Energy cost = energy consumption x unit cost = kWh x $/kWh = kW x hrs x $/kWhA 50-ton chiller with a 0.8 kW/ton efficiency costs about $11,200 annually when operating 2,800 load hours (40 kW x 2,800 hr x $0.10/kWh national average)

Source: stock.xchngSource: Commonwealth of Kentucky#5HVAC basicsTemperatureDry bulbNormal thermometerWet bulbBulb wrapped in clothcalled a sockthat is kept wet with water via wicking.Dew pointTemperature to which air must be cooled for the water vapor component to reach saturation and condense into water.Dry Bulb Temperature (F)Relative HumidityWet Bulb Temperature (F)Dew Point (F)70100%707060%615630%533855100%555560%484240%453730%Not SustainableIce

Source: Microsoft Encarta #6HVAC basicsRelative HumidityRelative humidity compares water vapor in the air with the concentration of water vapor that the atmosphere could hold (if the atmosphere were at saturation).Usually expressed as a percentage. When the actual concentration of water vapor in air is equal to the water vapor concentration at saturation, the relative humidity is 100%.There is one gallon of water in a 20' x 50' x 8' room at 68F and 100% RHThere is only 0.1 teaspoon of water per cubic foot of air at 68F and 100% RHOperation at 78F / 40% RH provides the same level of occupant comfort as 74F / 50% RH does due to evaporative cooling.

In this example, specific (absolute) humidity does not change until the dew point is reached.4C40F100%RelativeHumidityH2O#7HVAC basicsDegree DaysDegree day calculations provide a rough estimate of the heating and cooling load for a particular location.Degree days are based on the difference between a day's average daily temperature and the "balance point" temperature of 65F (or 18C). Cooling Degree Day (CDD) = (Average Temperature 65F) x days/monthHeating Degree Days (HDD) = (65F Average Temperature) x days/monthLocation dependent and data available from National Climate Data Center (NCDC),WeatherUnderground, and other sources.

Source: Utility Allowance#8HVAC basicsLoad HoursHVAC load hours may be calculated from degree days using a formula which incorporates Outside Design Temperatures. Cooling Load Hours (CLH) = CDD x 24 / (Cooling Outside Design Temperature 65F)Cooling Outside Design Temperature (ODT) is in the range of 70F to 105FHeating Load Hours (HLH) = HDD x 24 / (65F Heating Outside Design Temperature)Heating Outside Design Temperature (ODT) is typically between -12F and 40F.It is necessary to reduce the heating load hours by about 40% to match actual energy consumption.#9HVAC basicsHVAC Load Hours

Source: Louisiana Department of Natural Resources, Technology Assessment Division#10HVAC basicsEfficiency RatingsOne ton (12,000 Btu/hr) equals 3.516 kW at 100% efficiencyCoefficient of Performance (COP)COP = Rated Cooling Output, kBtuh / Rated electrical input, kBtuhFull Load Value (FLV)FLV = kW/tonCOP = 3.516 (kW/ton) / FLV efficiency rating (kW/ton)Energy Efficiency Ratio (EER)EER = Cooling output (Btu) / Electricity consumed (watt) EER = 12,000 Btu per ton / FLV (watt per ton) EER = COP x 3.413Application Part Load Value (APLV)Other than full loadIntegrated Part Load Value (IPLV)Weighted average of full load and part loadFLV(kW/ton)COPEER0.65.9200.754.7161.03.5121.52.38#11HVAC basicsSeasonal Energy Efficiency Ratio (SEER)Test conditions for determining SEER values are defined by ANSI/ARI standard 210-240-2008. Indoor air across the evaporator at 80F with 50% RH (wet) and