HVAC – Air Handling Unit

  • View
    47

  • Download
    3

Embed Size (px)

DESCRIPTION

hQ = 200,000 Btu/h. HVAC – Basic Terms. cQ. assumeto = 20. tr = 70. CO2. 50 people. 20 cfm/pers. tsi = 105. 1000 cfm. 20%. coil Q = V*rho *cp*TD 5000 cfm. ti = 62. hQ vent = V*rho*cp*TD. Heating. Ventilating. AC =Cooling. HVAC – Air Handling Unit. HVAC – Basic Terms. - PowerPoint PPT Presentation

Text of HVAC – Air Handling Unit

  • HVAC Air Handling UnitHeatingVentilatingAC =CoolingHVAC Basic TermshQ = 200,000 Btu/hCO220 cfm/pers50 people 1000 cfmcQassumeto = 20tr = 70ti = 62tsi = 10520%coilQ= V*rho*cp*TD5000 cfmhQvent = V*rho*cp*TD

  • HVAC Basic TermsBy Conduction Convection Radiation(Heating Load) Heat Out =Heat In(Cooling Load including Latent Load) Heat and Humidity in = Heat and Humidity out

  • HVAC Basic TermsConductionAreaTemperatureResistance

  • HVAC Basic TermsConduction

  • ConvectionRadiationHVAC Basic Terms

  • HVAC Basic Systems HeatinghQsen + hQvent = coilQsenhQsen = 200,000 Btu/h

  • HVAC Basic Systems Heating

  • wwHVAC Basic Systems - ACAC Water to Water

  • wAHVAC Basic Systems - AC

  • AAHVAC Basic Systems - AC

  • wAHVAC Basic Systems - AC

  • Constant Volume Double Duct Terminal BoxDamper blades change air flow as the pressure at the inlet to the box increases or decreases and in response to room temperature

  • Variable Volume Single Duct Terminal BoxPressure Independent (between Max and Min), based on room thermostat. If temperature rises, damper opens for more cooling.Air Flow is unaffected by other boxes in the system.55 60oP SensorThermostat = Master Velocity = Sub Master cfm

  • Inlet Guide Vanes

  • Variable Speed Drives

  • Variable Speed Drives

  • Variable Speed Drives

  • Variable Speed Drives

  • COP dimensionless! EER dimensions of Btu/h/W!HVAC - CoolingidealevQkpH

  • The energy efficiency rating (EER) of an air conditioner is its BTU/h rating over its Wattage.

    Example: window air conditioner Rating: 10,000-BTU/h Power Consumption: 1,200 watts EER = 10,000 BTU/h/1,200 watts = 8.3 Btu/Wh

    Normally a higher EER is accompanied by a higher price. HVAC - Cooling

  • Choice between two 10,000-BTU/h units

    1. EER of 8.3, consumes 1,200 watts EER of 10, consumes 1000 watts.

    Price difference is $100. Usage: 4 months a year, 6 hours a day. Electricity Cost: $0.10/kWh. ===========================================4 mo. x 30 days/mo. x 6 hr/day = 720 hours (720 h x .2 kW) x $0.10/kWh = $14.40 Savings

    Since the EER 10 unit costs $100 more, it will take about seven years for this more expensive unitto break evenHVAC - Cooling

  • Energy AnalysisExample

  • ECM: Heat Recovery