1 / 29

HVAC

HVAC. Refrigerant Properties. Objectives. After completing the material in this chapter, the student should be able to: List the desired properties for refrigerants. Explain the characteristics of hydrocarbons. Explain how a refrigerant becomes halogenated.

gsung
Télécharger la présentation

HVAC

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 Refrigerant Properties

  2. Objectives • After completing the material in this chapter, the student should be able to: • List the desired properties for refrigerants. • Explain the characteristics of hydrocarbons. • Explain how a refrigerant becomes halogenated. • Explain the chemical elements that make up CFC, HC, HCFC, and HFC refrigerants. • Differentiate between azeotropic, near-azeotropic, and zeotropic refrigerant blends. • Explain how ozone protects the Earth. • Explain the difference between good and bad ozone.

  3. Objectives • After completing the material in this chapter, the student should be able to: • Explain how ozone is destroyed. • Explain the concept of global warming. • Interpret ozone depletion potentials (ODP) and global warming potentials (GWP). • Determine the proper oil to use with various types of refrigerant. • Differentiate between reusable and disposable refrigerant cylinders. • Obey laws regarding certification and refrigerant handling.

  4. Objectives • After completing the material in this chapter, the student should be able to: • Differentiate between Type I, Type II, Type III, and Universal certification. • Differentiate between refrigerant recovering, recycling, and reclaiming. • Demonstrate passive and active recovery methods. • Demonstrate methods to recycle refrigerant.

  5. Refrigerant Types • Environmentally friendly • Non-toxic • Non-flammable • Chemically stable • Recyclable • Relative low cost • Detectable at low concentrations

  6. Ethane and Methane • Most refrigerants in use today originate from one of these two base molecules. • Methane and ethane are referred to as pure hydrocarbons. • Pure hydrocarbons contain only hydrogen and carbon. • Other hydrocarbons include propane and butane.

  7. Ethane and Methane • (A) Methane molecule (B) Ethane molecule

  8. Classes of Refrigerants in Use Today • Hydrocarbons (HC) • Hydrofluorocarbons (HFC) • Chlorofluorocarbons (CFC) • Hydrochlorofluorocarbons (HCFC)

  9. Ozone Depletion • Skin cancer. • Eye-related issues, including cataracts. • Decreased plant growth rates. • Compromised immune systems.

  10. Atmospheric regions Ozone Depletion

  11. Global Warming • Also referred to as the greenhouse effect. • Earth’s inability to release heat by radiation back to the atmosphere.

  12. Ozone Depletion Potential (ODP) • CFC refrigerants have high ozone depletion potentials. • HCFC refrigerants have lower ozone depletion potentials. • HFC and HC refrigerants have an ozone depletion potential of zero.

  13. Global Warming Potential (GWP) • CFC refrigerants have high global warming potentials. • HCFC refrigerants have lower global warming potentials. • HC refrigerants have low global warming potentials. • HFC refrigerants have very low global warming potentials.

  14. Refrigerant Oils • Alkylbenzenes • Glycols • Esters

  15. A list of refrigerants with their appropriate oils. Refrigerant Oils

  16. Refrigerant Cylinders • Disposable refrigerant cylinders • Reusable refrigerant cylinders • Recovery cylinders

  17. Refrigerant Cylinders • Disposable refrigerant cylinder

  18. Refrigerant Cylinders • Reusable refrigerant cylinders.

  19. Refrigerant Handling • Always be thoroughly familiar with surroundings. • Wear personal protection equipment (PPE) including safety glasses, gloves, and protective clothing. • Recovered refrigerant may be acidic. BE CAREFUL. • Do not inhale refrigerant vapors.

  20. Refrigerant Handling • When possible, work in well-ventilated areas. • Refrigerant containers should never be filled to more than 80% capacity. • Always secure cylinders before transporting. • Properly label all refrigerant cylinders.

  21. Refrigerant Handling • Store tanks in a cool, dry place. • Always maintain equipment and tools including recovery equipment, gauges, hoses, and refrigerant cylinders. • Dedicate hoses for use with specific refrigerants to reduce cross-contamination. • Change oil and filters regularly on recovery equipment.

  22. EPA Type 608 Certification • Type I – Small Appliances • Type II – High-Pressure and Very-High- Pressure Appliances • Type III – Low-Pressure Appliances • Universal – Type I, Type II, and Type III

  23. Refrigerant Recovery • Passive recovery: • Uses the system compressor to pump the refrigerant from the system to an approved DOT refrigerant cylinder • Active recovery: • When the system contains more than 15 pounds of refrigerant or if the system compressor is inoperative

  24. Refrigerant Recovery • Setup for passive refrigerant activity.

  25. Active recovery setup with moisture indicator and filter installed. Recovered Refrigerant Identification

  26. Summary • Refrigerants should be environmentally safe, non-toxic, non-flammable, and chemically stable. • Halogen refrigerants are created when some hydrogen atoms are replaced with chlorine or fluorine atoms. • Hydrocarbons (HC) contain only hydrogen and carbon. • Hydrofluorocarbons (HFC) contain only hydrogen, fluorine, and carbon. • Chlorofluorocarbons (CFC) contain only chlorine, fluorine, and carbon.

  27. Summary • Hydrochlorofluorocarbons (HCFC) contain only hydrogen, chlorine, fluorine, and carbon. • Blended refrigerants are mixtures of two or more other refrigerants and can be azeotropic, near-azeotropic, or zeotropic. • Stratospheric ozone protects the Earth from ultraviolet radiation. • Ozone molecules are destroyed by chlorine. • Chemical substances are rated by their ozone depletion potentials (ODP) and their global warming potentials (GWP).

  28. Summary • CFCs have high ODPs, while HFCs and HCs have low ODPs. • Synthetic oils can be alkylbenzenes, glycols, and esters. • Refrigerant cylinders are color-coded and can be reusable or disposable. • The Montreal Protocol Act paved the way for a number of regulations regarding refrigerant handling. • Technicians must be certified as per EPA Section 608 guidelines.

  29. Summary • Refrigerant can be recovered, recycled, or reclaimed. • Recovery involves the removal and storage of the refrigerant. • Recycling involves the filtering of refrigerant prior to reintroducing it to the system. • Reclaiming involves restoring the refrigerant to ARI 700 standards.

More Related