Questions and Answers

This Document
The purpose of this document is to answer the most commonly asked questions of the group. Internet users new to this group should read this document prior to posting questions. Your question may have already been asked and answered. You may not find answers to certain questions if those questions are not pertaining to charter issues, even if they are commonly asked.

Questions compiled here were mostly compiled from discussion in the group. If you have suggestions for items to be added to the FAQ, or comments on the answers given, please email your suggestions to me. I appreciate any suggestions you may have.

Theory, Heat transfer, Fundamentals, etc.

Q: Can anyone recommend a book covering ______ A: HVAC fundamentals? ASHRAE Handbooks: 1992 Equipment Volume 1993 Fundamentals Volume 1994 Refrigeration Volume 1995 Applications Volume Load Calculations? ASHRAE Cooling and Heating Load Calculation Manual Duct Construction and ductwork system design? SMACNA Duct construction standards SMACNA system design manual Air Conditioning systems design? Carrier systems design manuals (various softcover) Trane Air Conditioning Manual ASHRAE air-conditioning Systems Design Manual ISBN 1-8834-13-00-1 Modern Refrigeration and Air Conditioning Ventilation? Industrial Ventilation Refrigeration? Refrigeration Service Engineers Society (RSES) Service Application Manual (SAM) has extensive product and technical information covering all phases of refrigeration. Doolins Troubleshooting Bible


Q: Are scroll compressors better? A: Since they have fewer moving parts, they are said to be more reliable. Other advantages are debatable. Editors note: A scroll compressor uses two spiral shaped blades rather than reciprocating pistons to compress the refrigerant in it's hot gas state. The two spiral blades mesh together with close tolerances inside a chamber. Typically one of the two blades remains fixed while the other is moved in a circular motion. This motion causes gas to be trapped in a pocket and moves the gas outward in the spiral while the pocket gets smaller, thereby compressing the gas. Q: What are the typical fan pressures in a residential HVAC installation (furnace). A: The normal residential HVAC blower is designed for 0.25 to 0.5"wc, but this is total static pressure including the coil, filter, heat- exchanger, etc. Q: Can anyone tell me how EER differs from the SEER rating for air conditioning units? A: The EER is the cooling ouput divided by the electric input in KW, SEER is the EER at 85F outdoor modified by some cycling numbers


Controls, DDC, Pneumatics, etc.

Refrigeration and Refrigerants

Q: What are refrigerants? A: Fluids used to transport heat. Q: Do CFC refrigerants deplete the Earth's atmospheric ozone layer? A: Most scientist agree they do. Some other people disagree. Some CFCs do break down ozone more than others. Some CFCs survive in the atmosphere longer than others before breaking down. Regardless of whether or not they do, new laws have been enacted to limit the production and venting of CFCs. Using your web browser, you can visit the Usenet ozone depletion FAQ at: ` depletion/top.htm' Q: What is being done about CFCs depleting the ozone layer? A: Pursuant to the Montreal Protocol, CFC refrigerant production world- wide will cease (in developed countries) by January 1, 1996. In the United States, the Clean Air Act of 1990 requires CFC production to cease by that date. New refrigerants are currently under development and in production. There are also strict new laws designed to prevent venting of existing CFC refrigerants to the atmosphere. For more information about replacement refrigerants, visit the world wide web page `' You can also get voice and written information from the EPA Hotline at (800) 296-1996. For regulations relating to HVAC systems, ask for the fact sheet about section 608 of the Clean Air Act. There is also information about EPA reviews of replacement refrigerants. Q: Am I required to fix a leaking refrigerant system containing R-22? A: Under the current EPA regulations, only if the system contains more than 50 lbs of refrigerant. (Editors note: You would be well advised to fix the leak since this refrigerant will become scarce/expensive in the coming years. R-12 will be no longer produced after 1995, R-22 will be banned in 2020)

Indoor Air Quaility

Q: What is meant by Indoor Air Quality (IAQ)? A: In general, IAQ refers to the suitability for consumption by humans, of air inside a building. The following are some factors that might constitute poor air quality: * High levels of carbon dioxide (> 1000 ppm) * Harmful airborne bacteria * Airborne compounds resulting from manufacturing processes * Dust particles * Objectionable odors For the purposes of this group, IAQ does not generally refer to the temperature of, or amount of moisture in, indoor air.

Workplace & Business Issues

Internet, Computer and Software Resources

Q: Is this newsgroup sponsored by ASHRAE? A: Definitely not. Although ASHRAE employees and society members do participate in discussions regularly. Q: Is there an ASHRAE Web site or ftp site? A: Charles R. Miro of ASHRAE responds: No, ASHRAE does not presently have a Web site. The Society does have an email gateway to the Internet. ASHRAE runs a Bulletin Board System that provides email access to the Internet. For information on future expansion plans, please contact Efrain Ramirez, ASHRAE Data Processing Manager (voice: 404/636-8400; email: To access the BBS in Atlanta, use your modem to dial 404-235-0228 Editors note: You may telnet to the ASHRAE BBS system, use the domain name `'. It helps if your telnet client software has a standard BBS file transfer protocol such as Xmodem or Zmodem. Alternatley, you can access files using ftp to the domain `' Q: Where can I get shareware or freeware for residential heating/cooling load calculations A: Duane Beach, responded: BTU ANALYSIS (SHAREWARE VERSION) VERSION 2.3.0sw Heating and cooling load calculation software By: David W. Ostler, Distributed By:Enchanted Tree Software 901 Ferndale Blvd, High Point, NC 27262 BBS support found on: Public Safety BBS, Jamestown, NC Access at: (919) 886-8826 Editors Note: Current availability of this program has not been verified. If you can verify its availablity please let me know.

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