William Acorn, PE, FASHRAE

Acorn Consulting Services, LLC
Offices in Arizona and Washington
Mobile: 520-661-7664
Office: 602-888-7250
Fax: 520-577-0851

William R. Acorn is principal and founder of Acorn Consulting Services, LLC. A consulting mechanical engineer specializing in the built environment, Bill provides:

Project Design and Management Consulting
Forensic Analysis and Litigation Consulting
Expert Testimony at Legal Proceedings
Mentoring & Advanced Education

With more than 40 years of experience as a professional engineer, Bill is an internationally recognized authority on assessing, evaluating, conceptualizing and remediating complex project design, construction and operational issues related to the built environment. He has analyzed and designed hundreds of projects including commercial office buildings, healthcare facilities, institutional laboratories, and clean manufacturing facilities for the semiconductor and related advanced technology industries.

Bill has significant experience as an expert analyst of building system design and construction, environmental system control failures, code compliance issues and cause/effect relationships of performance issues related to the built environment. As a forensic engineer, litigation consultant and expert witness, Bill has represented plaintiffs, defendants and their insurers in a variety of domestic and international venues with litigation values to greater than $250MM US. Forensic assignments have included projects dealing with:

Heating, Ventilating and Air-conditioning (HVAC) systems,
Cleanrooms and other critically controlled environments,
Alleged exposures to chemicals in the work environment,
Industrial ventilation systems,
Power and Process piping systems,
Plumbing systems,
Energy management/control systems,
Commercial/industrial refrigeration systems,
Fires and explosions,
Exposure to carbon monoxide,
Exposure to Legionella,
Alleged misappropriation of intellectual property – patents and trade secrets,
Standard of care for design and construction professionals.

Bill’s experience as an engineer, project manager and design firm principal covers the spectrum including; programming, design, construction, start-up/commissioning, and operational facility evaluation and optimization. Bill and his predecessor firm were responsible for all aspects of design, development of construction documents, start-up and commissioning and construction phase support for new and retrofit projects. Although no longer providing detailed design and construction documents, Bill provides project consulting services; acting as an owner’s agent or extension of the staff of the designer and/or builder of complex projects. Bill’s services span the range from peer review of the design, to code compliance consulting, value engineering, sustainability, energy use evaluation and performance optimization recommendations.

Bill’s pragmatic approach to both project consulting and forensic/litigation consulting is the result of real-world experience and many years as a trainer and mentor in professional and academic settings. His ability to explain complex issues in a manner that is understandable to students, entry level engineers, managers and non-technical audiences is key to his success in the litigation consulting environment.

Professional Mechanical Engineer (P.E.) - Mr. Acorn is registered in Arizona, California, Colorado, Illinois, Iowa, New Hampshire, New Mexico, Nevada, Oregon, Texas, Utah and Washington, and is also registered with the NCEES “National Council of Examiners for Engineering and Surveying” (Certificate No. 6999).

As a visiting lecturer at Arizona State University, he delivers public and private seminars and workshops through their continuing education programs on topics including mechanical system design, project management and code compliance for advanced technology facilities. Bill was the “Eminent Scholar” in Cleanroom Design at the ASU School of Construction in 1997, the only non-academic ever appointed by the DEWSC to this position. During the period from 2002 – 2011 Bill was responsible for development and presentation of the mechanical engineering and code compliance portions of the curriculum for the graduate level course CON 598 “Design and Construction of Cleanrooms”.

Bill was involved from the inception of CREATE “Construction Research and Education for Advanced Technology Environments” at Arizona State University. This organization was charged with research and development related to the design and construction of advanced technology facilities. Bill continues to be involved with ACE “Alliance for Construction Excellence” at ASU.

As a visiting lecturer in the Department of Aerospace and Mechanical Engineering at the University of Arizona, Bill lectures on the analysis and design of environmental control systems (HVAC) for buildings.

The author of Code Compliance for Advanced Technology Facilities, Bill is widely recognized as an authority on the subject and regularly delivers seminars and workshops to industry and academia on hazardous occupancy code compliance. Bill also regularly consults with the regulatory community, owner/operators and design professionals concerning issues of life safety in semiconductor and similar hazardous facilities. In addition, Bill was a contributing author to the Semiconductor Safety Handbook edited by Richard A. Bolmen, Jr.

Bill has been recognized for technical achievements, innovation and foresight by peers, associates and clients. He was elected in 2007 to the status of Fellow in the HVAC industry-leading professional organization the American Society of Heating, Refrigerating and Air-Conditioning Engineers ASHRAE; a position that recognizes “unusual distinction and contributions to the art and science of the HVAC industry.” This recognition is achieved by fewer than 1% of the members of ASHRAE world-wide.

Bill has also attained the status of Board Certified Diplomate in Forensic Engineering granted by the National Academy of Forensic Engineers (http://www.nafe.org ), a Chartered Affinity Group of the National Society of Professional Engineers (https://www.nspe.org/ ).

Areas of Expertise
  • Building Codes
  • Chemicals
  • Construction
  • Design Engineering
  • Equipment & Machinery
  • Facility Engineering
  • Failure Analysis
  • Fire
  • Forensic Engineering
  • Hazardous Materials
  • Plumbing & HVAC
  • Products Liability
  • Semiconductors

Expert Background
Q: Please list your professional accreditations, degrees, licenses, and certificates granted:
A: Mr. Acorn graduated With Distinction from the University of Arizona in 1971 with a Bachelor of Science degree in Mechanical Engineering. Mr. Acorn is registered as a Professional Mechanical Engineer in the States of Arizona, California, Colorado, Illinois, Iowa, Nevada, New Hampshire, New Mexico, Oregon, Texas, Utah and Washington. He is also registered with the National Council of Examiners for Engineering and Surveying, Certificate No. 6999.

As an Adjunct Professor in the Arizona State University Del E. Webb School of Construction, he delivers seminars several times a year through their continuing education program on topics including design, project management and code compliance for advanced technology facilities. Mr. Acorn teaches a variety of graduate level courses and workshops at this institution. Mr. Acorn has been involved since the inception of the organization known as CREATE Construction Research and Education for Advanced Technology Environments at Arizona State University.
Q: Please list your affiliations or memberships in any professional and/or industry organizations:
A: American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) - Fellow, Past Treasurer College of Fellows, Past President of Tucson Chapter;
National Society of Professional Engineers (NSPE);
National Academy of Forensic Engineers (NAFE) Board Certified Diplomate
Refrigeration Service Engineers Society (RSES);
International Code Council (ICC);
Alliance for Construction Excellence (ACE) - Arizona State University, Tempe, AZ;
Forensic Expert Witness Association (FEWA);
National Association of Corrosion Engineers (NACE);
Tau Beta Pi, National Engineering Society.
Q: Please list any teaching or speaking experience you have had, including subject matter:
A: Mr. Acorn has presented numerous seminars and workshops (varying in length from two hours to three days) including the subjects of Forensic Engineering, Hazardous Occupancy Code Compliance, technical subjects (such as thermodynamics, air handling and distribution, environmental control systems, hydraulics, etc.) related to the design of advanced technology manufacturing and research and development facilities. Representative activities and presentations include:
• SESHA 2015 – International High Technology ESH Symposium & Exposition, May 2015 – Keynote Speaker – Litigation of Worker Health Issues – Lessons Learned.
• Arizona State University, Tempe, AZ: Adjunct Instructor associated with the development of curriculum for graduate level course Con 598 “Design and Construction of Cleanrooms” in the Del E. Webb School of Construction, College of Engineering. Instructs in the area of cleanroom design, contamination control theory and strategies for HVAC systems and overall facility organization. In addition, Bill teaches the module “Code Compliance for Hazardous Occupancies”. 2002- present.
• Project Manager Development Program (PMDP) – 2006 – 2014. Through association with ASU, instruction and team development leader for facilities design and construction project managers for Intel. This is a combined distance learning and one week hands-on workshop to develop the analytical and problem solving skills of new project managers for advanced technology facilities worldwide.
• University of Arizona, Tucson, AZ: Adjunct Instructor in a team teaching program for AME 442 – Fundamentals of Environmental Control Systems. This course has been delivered in the AME department by the team since 2008.
• Forensic Engineering Analysis of HVAC Systems – Why HVAC Systems Go Wrong – presented at the National Academy of Forensic Engineers Summer Seminar, Arizona. 2011.
• SESHA/IHTESH 2011 Symposium – Disaster Preparedness Roundtable – presented discussion of several large losses incurred by semiconductor and similar advanced manufacturing clients that resulted not only in business interruption, but significant out-of-pocket expenses. Case studies addressed: 1. Fire in wafer fab – catastrophic losses, business interruption, lengthy litigation, 2. Fire in flat panel display manufacturing facility catastrophic losses, business interruption, lengthy litigation, 3. Chemical leak in wafer fab -catastrophic losses, business interruption, lengthy litigation, 4. Alleged unsafe environments in wafer fabs result in employee claims and protracted lawsuits.
• Peer Review vs. Litigation Consultant Services for Your Project – Seminar presented by Mesch Clark Rothschild to construction industry attendees – owner, contractors and design professionals. 2010.
• Intel Code Compliance Workshop 2010 – conducted under the auspices of ASU Del E. Webb School of Construction and CREATE, this two day workshop provided insight into the current International Codes and practical applications in large modern wafer fabs and similar facilities that frequently require alternative methods and means (AMM) compliance strategies.
• Avoiding Litigation in Design and Construction – presented to ASHRAE Tucson Chapter in conjunction with Mel Cohen, Esq. Discussion of teaming and contractual methods of preventing design and construction disputes that lead to litigation. 2007.
• Project Management for Advanced Technology Facilities – via ASU and CREATE, July, 2004 - on site lectures and web based continuing education workshop.
• Eminent Scholar in Cleanroom Design, 1997 - “Expediting the Delivery of Advanced Technology Factories”. Arizona State University, Tempe, AZ - graduate course on cleanroom design and construction in the Del E. Webb School of Construction, College of Engineering.
• University of Wisconsin, Milwaukee: Course Leader for "Code Compliance for Advanced Technology Facilities" seminar based upon his textbook of the same name. This two day course was held several times a year between 1995 and 1998 at locations around the country and was attended by designers, builders and owners of advanced technology facilities. Mr. Acorn was an Adjunct Professor through the UWM Center for Continuing Engineering Education.
• Texas Instruments (Dallas Texas) – “Code Compliance for Hazardous Occupancies” May and June, 2000.
• Arizona State University – Cleanroom Construction Workshop – featured lecturer in this one week workshop for industry and academia, sessions presented are “Environmental Systems (HVAC)” and “Code Compliant Design of Hazardous Cleanroom Facilities” – presented twice a year – 1996 through spring 2000.
• Micron Technology Inc. – Project Management and Delivery Systems Workshop – four day workshop for private client at Lehi Utah site. July 2001.
• Semiconductor Safety Association International Symposium – professional development course – “Building Codes and Standards for Environmental Health and Safety Professionals” – New Orleans, April 2001.
• “Creating a Safer Working Environment in Clean Manufacturing Facilities” - Cleanrooms East 2000.
• Decommissioning an Advanced Technology Manufacturing Facility, Concepts for Demolition of Re–use - Cleanrooms East 2000
• Cleanrooms West 1998 – Environments for Tool Manufacturing – “How to design and build more effective environments for the manufacturing of process tools”.
• “A New Project Delivery Paradigm - Getting to Market Faster through Rational Teaming”- CleanRooms West ’98.
• “What we Need to Do Now - A New Paradigm in Capacity Enhancement Strategies”- CleanRooms West ’97.
• Intel Corporation (Albuquerque, Chandler and Hillsboro) – “Code Compliance for Hazardous Occupancies”. Several sessions 1995 to 1998.
• Motorola, Austin, Mesa and Phoenix – “Code Compliance for Hazardous Occupancies”. Several sessions 1992 to 1995.
• Motorola, Mesa, AZ - HVAC System Design Considerations – 1990.
• Hewlett Packard (San Jose, Corvallis Oregon) – “Code Compliance for Hazardous Occupancies”. Several sessions 1996.
• Atmel (Colorado Springs) – “Code Compliance for Hazardous Occupancies”. Several sessions 1995 to 1998.
• IESH, International Conference presentation of paper on “Energy Conservation Opportunities in Advanced Technology Factories” – May 1996.
• Northern Telecom (Rancho Bernardo and Ottawa) – “Code Compliance for Hazardous Occupancies” - 1993.
• Austin Major Facilities Users Group - SEMATECH, Advanced Micro Devices, Motorola, IBM, MCC, Texas Instruments “Code Compliance for Hazardous Occupancies” - 1994.
• San Diego County Fire Prevention Officers Section – “Code Compliance for Hazardous Occupancies”.
• University of Arizona, Tucson, AZ: Visiting Lecturer in the College of Architecture. Developed and presented curriculum and studies in the field of fundamentals and design strategies for HVAC Systems in buildings. Taught senior-level class part-time from 1974 to 1983. Approximately 100 students per semester.
• American Society for Heating, Refrigerating & Air Conditioning (ASHRAE) Numerous technical seminars including duct design, acoustics, energy conservation, automation and controls, thermodynamics, psychometrics, hydraulics, air distribution, etc.
• Energy Conservation in HVAC System Design and Operation - National Society of Professional Engineers (NSPE) Tucson, AZ chapter.
• “Evaluation of Failed HVAC Systems” - National Academy of Forensic Engineers (NAFE) – annual conference.
• “How To Build Cleanrooms Fast” - CleanRooms West ’95.
• “Code Compliant Design of Hazardous Occupancy Facilities” - CleanRooms West ’93.
Q: Have any of your accreditations ever been investigated, suspended or removed? (if yes, explain)
A: No
Q: On how many occasions have you been retained as an expert?
A: Over 50
Q: For what area(s) of expertise have you been retained as an expert?
A: HVAC and Refrigeration
Process and Power Piping
Plumbing Systems
Standard of Care in Design and Construction
Chemical Exposures in the Workplace
Cleanroom Design and Performance
Codes and Standards
Patent and Trade Secret Disputes
Q: In what percentage of your cases were you retained by the plaintiff?
A: 50%
Q: In what percentage of your cases were you retained by the defendant?
A: 50%
Q: On how many occasions have you had your deposition taken?
A: Approximately 12
Q: When was the last time you had your deposition taken?
A: December 2017
Q: On how many occasions have you been qualified by a court to give expert testimony?
A: 5 to 10. Note that most cases have been resolved during discussions and negotiations.
Q: On how many occasions have you testified as an expert in court or before an arbitrator?
A: 20
Q: For how many years have you worked with the legal industry as an expert?
A: Approximately 25 years
Q: What services do you offer? (E.g.: consulting, testing, reports, site inspections etc.)
A: Consulting
Site Inspections
Expert Testimony
Q: What is your hourly rate to consult with an attorney?
A: Available upon request
Q: What is your hourly rate to review documents?
A: Available upon request
Q: What is your hourly rate to provide deposition testimony?
A: Available upon request
Q: What is your hourly rate to provide testimony at trial?
A: Available upon request
Q: Please list any fees other than those stated above (E.g.: travel expenses, copy fees, etc.)
A: Negotiated on a project by project basis.


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