exam is on november 6 2012 in class exam n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Exam is on November 6, 2012 in class exam PowerPoint Presentation
Download Presentation
Exam is on November 6, 2012 in class exam

Loading in 2 Seconds...

  share
play fullscreen
1 / 13
giza

Exam is on November 6, 2012 in class exam - PowerPoint PPT Presentation

204 Views
Download Presentation
Exam is on November 6, 2012 in class exam
An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Exam is on November 6, 2012 in class exam Example exams are posted on the course website

  2. Lecture Objectives: • Address HW3 questions • Use of eQUEST • Continue with HVAC Systems • modeling of HVAC Systems

  3. Roof top AHU fresh air filter mixing Fan air from building to building Evaporator Gas/Electric Heater Air-conditioning in Air Handling Unit (AHU) AHU AHU schematic Exhaust From room Return fan flow control dampers Supply fan Compressorand Condenser Fresh air To room Outdoor air hotwater coolwater

  4. Processes in AHU presented in Psychrometric in psychrometric Case for Summer in Austin OA MA IA SA

  5. Refrigeration Cycle Released energy (condenser) T outdoor air T cooled water - What is COP? - How the outdoor air temperature affects chiller performance? Cooling energy (evaporator)

  6. Building-System-Plant HVAC System (AHU and distribution systems) Plant (boiler and/or Chiller) Building

  7. Building HVAC Systems (Primary and Secondary Building Systems) AHU – Air Handling Unit Distribution systems Fresh air For ventilation AHU Primary systems Air transport Electricity Secondary systems Cooling (chiller) Heating (boilers) Building envelope HVAC systems affect the energy efficiency of the building as much as the building envelope Gas (or Gas)

  8. Building Heating/Cooling System Plant Integration of HVAC and building physics models Load System Plant model Building Qbuiolding Heating/Cooling System Q including Ventilation and Dehumidification Plant Integrated models

  9. Example of System Models:Schematic of simple air handling unit (AHU) Mixing box m - mass flow rate [kg/s], T – temperature [C], w [kgmoist/kgdry air], r - recirculation rate [-], Q energy/time [W]

  10. Energy and mass balance equations for Air handling unit model – steady state case The energy balance for the room is given as: mS is the supply air mass flow rate cp- specific capacity for air, TRis the room temperature, TS is the supply air temperature. The air-humidity balance for room is given as: wRand wS are room and supply humidity ratio - energy for phase change of water into vapor The energy balance for the mixing box is: ‘r’ is the re-circulated air portion, TO is the outdoor air temperature, TM is the temperature of the air after the mixing box. The air-humidity balance for the mixing box is: wOis the outdoor air humidity ratio and wM is the humidity ratio after the mixing box The energy balance for the heating coil is given as: The energy balance for the cooling coil is given as:

  11. Non-air system Radiant panel heat transfer model

  12. Non-air system Radiant panel heat transfer model The total cooling/heating load in the room The energy extracted/added by air system The energy extracted/added by the radiant panel: The energy extracted/added by the radiant panel is the sum of the radiative and convective parts: The radiant panel energy is: