1 / 17

HVAC Systems Overview

HVAC Systems Overview. Agenda. Psychrometric questions? Larger ‘psycho’ chart Email address list Project teams formed… topics? Overview of HVAC systems, types. HVAC Systems Overview. External Factors Ambient temperature, humidity Solar radiation Wind. Equipment. Internal Factors

adele-puckett
Download Presentation

HVAC Systems Overview

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HVAC Systems Overview HVAC Overview - # 1

  2. Agenda • Psychrometric questions? • Larger ‘psycho’ chart • Email address list • Project teams formed… topics? • Overview of HVAC systems, types HVAC Overview - # 2

  3. HVAC Systems Overview • External Factors • Ambient temperature, humidity • Solar radiation • Wind Equipment • Internal Factors • Occupants • Moisture gains • Acceptable environment (comfort, health and safety) • Internal air distribution HVAC Overview - # 3

  4. General Design Issues with HVAC • Determine required indoor conditions • Temperature and humidity levels • Ventilation • Determination of loads (cooling or heating) • Heat transmission through building shell • Heat gains from occupants • Heat gains from lighting and equipment • Ventilation and infiltration/exfiltration • HVAC system type • Building size, # of subdivisions • Local energy prices • Local climate • Initial cost versus life cycle cost • Other considerations • Energy usage • Indoor air quality HVAC Overview - # 4

  5. Type of Systems • All air • Water / air • All water • Centralized versus decentralized HVAC Overview - # 5

  6. Typical thermodynamic processes Cooling and dehumidifying moist air Evaporative cooling Humidity Ratio (W)   Dry Bulb Temperature Zone conditions,    Nearly saturated supply,   Ambient HVAC Overview - # 6

  7. Typical processes (Cont’d) Heating     Ambient Ambient,  Zone conditions,  Mixed zone/ambient,  Heating to supply air, HVAC Overview - # 7

  8. Direct Expansion Air Conditioning Outdoor Air COND Expansion Valve Compressor EVAP Supply Air Return Air Mixed Air Outdoor Air HVAC Overview - # 8

  9. Common System Types Central systems, Variable Air Volume (VAV) Exhaust Air Return Fan VAV Supply Conditioning Coils Ventilation Air Supply Fan HVAC Overview - # 9

  10. Common System Types Central systems, Dual Duct Heating Coil (Hot Deck) Exhaust Air Return Fan Mixing Boxes Filters Ventilation Air Cooling Coil (Cold Deck) Supply Fan HVAC Overview - # 10

  11. Common System Types Fan Coil Units (Unit Ventilator) Supply Air Supply Fan Cooling Coil Heating Coil Drain Pan Filters Ventilation Air Return Air HVAC Overview - # 11

  12. Common System Types Packaged Unit (Rooftop or Sidewall) Direct Expansion Cooling Heat Pump or Gas Fired Heating Supply Air Return Air Alternate Supply and Return Ductwork HVAC Overview - # 12

  13. Common System Types Split-System Return Air Condensing Unit Furnace Evaporator Refrigerant Lines Supply Air HVAC Overview - # 13

  14. Chilled Water Systems Cooling Tower Chiller Chilled Water System  Various System Loads (Coils) HVAC Overview - # 14

  15. Energy Recovery from Ventilation Air • One common approach is enthalpy wheel Exhaust Intake Outdoor Air Exhaust Air Cooling Mode Supply Air Return Air Heating Mode Supply Air Return Air OA Exhaust Air HVAC Overview - # 15

  16. Economizer Systems Exhaust Air Return Air Recirculation Air Supply Air @ Mixed Conditions Outdoor Air • Get ‘free cooling’ by using up to 100% outdoor air supply to room • Controllers use enthalpy (T and H) or temperature only for control decision HVAC Overview - # 16

  17. Economizer Systems    Ambient Ambient,  Zone conditions,  Mixed zone/ambient,  Mixed air conditions: Cooling provided to building: HVAC Overview - # 17

More Related