G-91 Supervision of Natural Gas Co-generation System


The G-91 Certificate of Fitness is required for supervision of natural gas co-generation system.  Cogeneration is the process whereby a fuel source, such as natural gas or liquid fuel, is used to produce both electrical and thermal energy. Cogeneration equipment captures that heat and uses it to supply hot water, steam, space heating and cooling.

This Certificate of Fitness is valid only at a specific location and for the specific person to whom it is issued.

  • New Application Fees: $25
  • Renewal Fees: $15
  • Application Reviewed Within: 1-2 Days
  • Renewal Cycle: 3 Years

Before You Submit Your Application

You must pass a written exam to get a G-91 Certificate of Fitness.
All applicants should review the Notice of Exam and Study Materials.

Applicants who need to take the exam must apply in person and bring the following documents

  • Completed Certificate of Fitness Application Form
  • A manufacture training document.
  • A written evidence of training by the manufacturer for the specific cogeneration system as well as safety procedures for the equipment installed at the COF applicants’ work place(s) must be submitted. System that is on the completion certificate must match system described by employer’s recommendation letter.
  • A copy of high school diploma or equivalency.
  • G-91 Sample of Recommendation Letter

Apply in Person

Applicants who need to take the exam must apply in person at:
9 MetroTech Center
Brooklyn, NY 11201

For More Information

NYC Fire Department (FDNY)
Public Certification Unit
9 MetroTech Center, 1st Floor
Brooklyn, NY 11201
Phone: (718) 999-1988
Email: pubcert@fdny.nyc.gov or call 311

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