Presentation on theme: "HVAC 101 The Basics of Heating, Ventilation and Air Conditioning"— Presentation transcript:
1HVAC 101 The Basics of Heating, Ventilation and Air Conditioning Presented by: Mike Barcik and Jeff Ross-Bain, PESouthface Energy Institute
2Southface Energy Institute Sensible Solutions for Environmental Living Energy Code WorkshopsGreenprintsCommercial SystemsEarthCraft House
3HVAC Heating, Ventilation and Air Conditioning Provides comfort for peopleAllows humans to exist under adverse conditions.
4Comfort Mold Comfort is primary intent of HVAC systems. Productivity Building DurabilityHealthMold
5Load Calculations Heating and Cooling Accuracy important! Design conditionsBuilding shell loadR, U valueInternal loadVentilation loadInfiltrationOccupancy schedules
6Heat Transfer Conduction Convection Radiation Resistance (R-Value) U = 1 / RQ = U x A x TU-Value is the rate of heat flow in Btu/h through a one ft2 area when one side is 1oF warmer
7Solar Heat Gain Coefficient The amount of solar heat energy allowed to pass through a windowExample: SHGC = 0.40Allows 40% through and turns 60% awaySolar Heat Gain Coefficient (SHGC)The glazing’s effectiveness in rejecting solar heat gain.Part of a system for rating window performance used by the National Fenestration Rating Council (NFRC)Gradually replacing shading coefficient (SC) in product literature and design standards convert SC to SHGC by multiplying the SC value by 0.87
14Split System Heating and Cooling Equipment Temperature & DuctworkHeatingand CoolingEquipmentFURNACETemperature &Humidity ControlsA/C UNITAn HVAC system consists of aheating and/or cooling source,a distribution system (e.g. ductwork or hot/chilled water piping) andtemperature controls.
15Heat Pump Operate on simple refrigeration cycle Reversing the cycle provides heatingTemperature limitationsAir to airWater sourceGeothermalLake coupled
23EconomizersFree cooling source: When available, use cool outdoor air instead of mechanically cooled air.Minimum supply of outside air55 oF and up55 oF85%outside air85%exhaust80 oF80 oFNormal OperationOutside air dampers are positioned to provide the minimum outside airEconomizer OperationOutside air dampers are fully open. Maximum outside air is providedHVAC-23
24Zoning and Economizers Economizers provide “free cooling” when outdoor conditions are optimalProper orientation & zoning yields comfort & efficiencyNSWECoreHVAC-24
31Improved Ventilation Effectiveness Mechanically provide filtered and dehumidified outdoor air to the breathing spaceVary ventilation based on the number of occupants and process loads - changes in occupancy can be measured by CO2 sensorsConsider designs that separate ventilation and space conditioningUtilize heat recovery systems to reduce system size and ventilation energy costs
32Improved Ventilation Effectiveness Effective mixing of ventilation air within spaceNet positive pressure in the southeast; exhaust from appropriate spacesProvide clean outdoor air, avoid:loading docksexhaust ventsplumbing stackswaste collectionstagnant water
33Additional Information / Resources ASHRAE – The American Society of Heating, Refrigerating and Air-Conditioning EngineersSouthface Energy InstituteGeothermal heat pump consortium