2-5。1。7 Operating light on exhaust air system motor。  When a sensor indicates a malfunction, trigger an alarm that is both audible and visible in the shop space。

2-5。1。8 Operating ranges on all gauges clearly marked。  Locate gauges on an annunciator panel (except hood static pressure gauges)。 Provide a 3-way valve at each gauge connection for cleanout and calibration; see Figure 2-5。

2-5。1。9 Place room differential pressure sensors away from doors, windows, and replacement air discharge。

2-5。2 Interlocks。  Provide an interlocked on-off switch so that the replacement air and exhaust air systems operate simultaneously。 When there are multiple fans, clearly label which exhaust fan is interlocked with which supply fan。

2-5。3 Annunciator Panel。  Provide an annunciator panel to continuously monitor ventilation system performance。 Locate the panel so it is accessible to shop personnel。 The panel must include, but is not limited to, all gauges (except hood static pressure gauges) described in paragraph 2-5。1。 Mount fan motor operating lights and interlocked ON/OFF switch on the panel。 The interlocked switches must clearly show which exhaust and supply fans are interlocked, where multiple fans are used。 The panel should indicate what action to take when operation falls outside the prescribed ranges。 For example, “examine/replace filter on R。A。 unit when this gauge reads outside indicated range。”

Figure 2-5。  Annunciator Panel。

2-6 OPERATIONAL CONSIDERATIONS

2-6。1 Provision for System Testing。  Provide access to the fan and motor to measure voltage, amperage, and fan speed。 Specify that all testing will be done in accordance with the ACGIH IV Manual, Chapter 9, “Monitoring and Testing of Ventilation Systems。”

2-6。2 Energy Conservation。  Incorporate applicable energy conservation measures in the design of all industrial ventilation systems。 Criteria herein minimize volume flow rates through appropriate designs。 Evaluate life cycle costs for heat recovery systems and specify when appropriate。 Refer to ASHRAE Handbook, HVAC Systems and Equipment and MIL-HDBK-1003/3 for details。

2-6。3 Recirculation。  Industrial ventilation systems use a large quantity of air。 Exhaust air recirculation is discouraged for most Naval industrial processes and prohibited by OPNAVINST 5100。23 for processes generating lead and asbestos。

Follow the re-circulated air guidelines set forth in UFC 3-600-01, Design: Fire Protection Engineering for Facilities and NFPA 654, Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids for fire protection; the ACGIH IV Manual and ANSI Z9。7, Recirculation of Air from Industrial Process Exhaust Systems for health protection, and the applicable OSHA standards when recirculation is included in the design。

2-6。4 Maintenance。  Require the contractor provide an operation and maintenance manual for the system and also provide hands-on training for maintenance and shop personnel。

2-7 SAFETY AND HEALTH CONSIDERATIONS

2-7。1 Posting。  For those systems where the replacement air is critical to the proper operation of the system, consider posting the following sign at each entrance to the ventilated space:

2-7。2 Noise。  Use engineering controls as the primary means of protecting personnel from hazardous noise。 It is cheaper to eliminate potential noise problems during the design or procurement stages, than it is to retrofit or modify after installation。 Determine the acoustic environment of any kind of activity in advance, both to fulfill the design goals and prevent the need for corrections at a later stage。