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Innovative Thinking :: Value Driven B U I L D I N G E N G I N E E R I N G 8721 Plantation Lane • Suite 301 Manassas, Virginia 20110 Tel: 703-366-3663 • Fax: 703-656-4886 www.mepdesigns.com ENGINEER SUBJECT DISCIPLINES DESCRIPTION TECHNICAL MEMO # DATE Mech Elec Plum GAS FA FS DATE UPDATED 2017-04 4.27.2017 Sam Abdelfattah Design of ME Systems in Repair Garages ✘ ✘ The provisions governing the design of mechanical and electrical systems in commercial repair garages are scattered between various building codes and standards that cross reference each other. Most applicable building codes and standards are: # International Mechanical Code (IMC), Section 502 # International Fire Code (IFC), Section 2311 # National Electrical Code (NEC), Article 511 # NFPA-30A: Code for Motor Fuel Dispensing Facilities & Repair Garages Additionally, International Fire Code, chapter 35, limits gas and arc welding in such facilities. Note that the guidelines in this memo does not apply to the design of mechanical and electrical systems in parking garages. The design decisions of M&E systems in vehicle repair facilities are driven by two factors: 1- The type of fuel used in the vehicles that will be repaired, Gas vs Diesel vs CNG 2- The level of electrical classification that can be tolerated without adversely affecting project goals and building operation Design Guidelines: 1- Repair garages are designated for either minor repair or major repair, according to the sorts of functions that will be performed in the facility, refer to definitions in NEC, Article 511 and NFPA-30A. 2- Floor areas in major repair garage up to 18" AFF are considered classified, unless 4 ACH mechanical ventilation is provided and the vents for exhaust and makeup air are within 12" of the floor. 3- Floor areas in minor repair garages without pits or below grade work area are considered unclassified. 4- Ceiling areas in repair garages where CNG fuel vehicles are repaired or stored are classified up to 18" below the highest point of the ceiling, unless 1 CFM/SF ventilation irate s provided, and the vent locations must be within the highest 18". 5- Areas adjacent to classified locations shall be unclassified if mechanically ventilated at 4 ACH, designed with positive pressure, or effectively cut off from the classified area by walls or partitions.
