ASHRAE Safety Standards. Mechanical Rooms and Gas Detection in Commercial Applications

Transcription

1 HA University ASHRAE Safety Standards Mechanical Rooms and Gas Detection in Commercial Applications presented by Greg Kaufman - Honeywell Analytics

2 Gas Hazards Three main types of Gas Hazards: Flammable Toxic Asphyxiant Risk of Fire and/or Explosion Risk of Poisoning Risk of Suffocation Methane, Butane, Propane, Hydrogen Carbon Monoxide, Hydrogen Sulfide, Chlorine, Nitrogen Dioxide Oxygen deficiency - Oxygen can be consumed or displaced by another gas

3 Measuring Hazards Oxygen Content A percentage by volume in air Flammable / Combustable / Explosive: % of volume in air (% VOL) % of LEL (% LEL) Toxic gases (Including many refrigerants): Measured in ppm (Parts Per Million) in air

4 Oxygen Depletion Measurement Terms Oxygen Percentage Volume in Air Oxygen Depletion: Ambient conditions where oxygen levels are being reduced to unsafe levels where occupants will experience breathing difficulty, symptoms, and/or death OSHA 19.5% Alarm Level

5 Units of Measure 1 Inch in 16 Miles 1 Minute in 2 Years 1 Penny in 10,000 Dollars 1 Ounce of Salt in 31 Tons of Potato Chips 1 Drop of Vermouth in 80 Fifths of Gin 1 Square Foot in 23 Acres 1 Bogey in 2,300 Golf Tournaments

6 Explosive Gas Measurement Terms LEL = Lower Explosive Limit UEL = Upper Explosive Limit 100% LEL for hydrogen is 4% V/V 100% LEL for methane (natural gas) is 5% V/V Alarm Level

7 State of Gases in Ambient Air The density of the gas determines where gas can be detected. At ceiling level: Lighter than air At breathing level: Equivalent to air density At floor level: Heavier than air

8 Alarm Setpoints Toxic Gases Time weighted average (TWA): Concentration levels that nearly all workers can be exposed to, during an 8 hour workday or 40 hour workweek, without suffering adverse affects. Short-term exposure limit (STEL): Maximum concentration to which workers can be exposed for a period of 15 continuous minutes. Ceiling concentration level (CCL): Exposure limit that should not be exceeded even momentarily.

9 Sensing Methods Diffusion: Sensor within the detection area Sample Draw: Sensor at a remote or distant location transported via pump, tubing & draw point

10 Application Focus - Parking Garage / Loading Dock Background In parking structures, CO is one of the most abundant airborne contaminants and poses significant safety concerns. With the addition of diesel vehicles, NO2 is also a concern These levels must be controlled or ventilated when concentrations approach unsafe levels.

11 Indoor Parking/Dispatch Facilities Carbon Monoxide (CO)& Nitrogen Dioxide (NO2)

12 Application Focus - Parking Garage / Loading Dock OLD MINDSET To provide fresh air in a facility where vehicles are present, a pre-determined air exchange per hour is required. This can be expensive for a number of reasons TODAY S SOLUTION By allowing the CO detection system to dictate when fans need to run, safety concerns are addressed and money is saved (Demand Controlled Ventilation = ROI)

13 Enclosed Parking Garages IMC 2012 Section MC-404. Enclosed Parking Garages: Enclosed parking garages. Mechanical ventilation systems for enclosed parking garages shall be permitted to operate intermittently in accordance with Item 1, Item 2 or both. 1. The system shall be arranged to operate automatically upon detection of vehicle operation or the presence of occupants by approved automatic detection 2. The system shall be arranged to operate automatically by means of carbon monoxide detectors applied in conjunction with nitrogen dioxide detectors. Such detectors shall be installed in accordance with their manufacturers' recommendations Minimum ventilation. Automatic operation of the system sha11 not reduce the ventilation airflow rate below 0.05 cfm per square foot ( m3/s m2) of the floor area and the system shall be capable of producing a ventilation airflow rate of 0.75 cfm per square foot ( m3/s m2) of floor area.

14 ZONE 1 ZONE 2 ZONE 1 ZONE 3 ZONE 2 ZONING Reduces energy costs Control relay activation (time delays) Use energy only as needed, where needed! ZONE 3

15 Determining the Number of Sensors Gas Radius of detection Area covered CO*, NO 2 * 50 ft 5,000-7,000 ft 2 Others ft 1,250-1,500 ft 2

16 Parking Garage Application

17 Parking Garage Application

18 CONFIGURATION OPTIONS

19 Application Focus Vehicle Bay Stand-Alone sensor Strobe & Horn

20 Application Focus Fire Department Engine/Hospital Ambulance Bays/Loading Docks Engine Bays and Loading Docks present hazard for CO & NO 2 Remote sensor Strobe & Horn

21 Configurations SMALL TO MEDIUM NETWORKS MONITORED BY MAIN CONTROLLER Horn-strobe Modbus communication Horn-strobe Main Controller Relay module Modbus communication Up to 3 x 32 units Horn-strobe Network sensors can be CO or NO2 or combination of both on the same network

22 Chiller Rooms

23 Mechanical Rooms Operational Issues Using the ANSI/ASHRAE Standard as a Giudance Document for Mechanical Rooms Gas Detection System Requirements Alarm Levels System Operations

24 Mechanical Room Example

25 Typical Installation

26 Sensing Methods Diffusion: Sensor within the detection area Sample Draw: Sensor at a remote or distant location transported via pump, tubing & draw point

27 Mechanical Room Hard Wired

28 Mechanical Room Sample Draw Chiller Area

29 Installation Examples Hard wired refrigerant sensor Main Refrigerant Controller includes fan start/stop override

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31 Installation Examples Remote Annunciator Panel includes fan start/ only

32 Installation Examples Controller with BACNet Refrigerant Controller

33 Value Proposition of a Hard-wired leak detection system Flexibility Multiple Refrigerants, Toxic & Combustible in a single system Constant detection, no sequential sampling No moving parts or wearable parts (tubing, filters, pump) that require upkeep and maintenance Decreased labor/installation costs Supervised detection system: if communication with the sensor is lost, a fault condition activates. If the tubing is cut as with a draw system, there is no indication

34 Value Proposition of a Sample Draw leak detection system Low cost per point (although overall system cost needs to be addressed) Ability to target a specific area of the chiller or MER

35 Boiler Rooms/Gas Meter Rooms Methane & Carbon Monoxide - detection at the source

36 A STEP IN THE RIGHT DIRECTION Pro: Low cost per device Con: Intended for Residential use ONLY Not recommended for low level detection No option for natural gas detection No supervised outputs Requires long exposure and high levels before alarming No relay outputs

37 BETTER OPTION Pro: Low cost per device Resides on the fire alarm system Supervised Con: Requires numerous devices reducing cost effectiveness Once alarmed, business interruption a certainty Not recommended for low level detection No option for natural gas detection

38 BEST OPTION Pro: Targeted, immediate detection at the source Low level detection Provides opportunity for ventilation activation & danger remediation Avoid costly business interruptions Lower overall costs Supervised contacts Sensor s working status and performance monitored Carbon Monoxide & Natural Gas or Propane detection

39 Co Sensor (x2) Gas Sensor (x4) Transmitter (x4) Horn/Strobe (x5) Panel mounted on existing uni-stut Remote Annunciator Panel Building 21 Boiler Boiler Boiler Sensors Mounted above boilers, appr from ceiling at edge of catwalk Roll up door Transmitters mounted on wall 5 above Catwalk Roll up door Boiler

40 Battery Rooms/Data Centers Hydrogen (H2) & Refrigerants

41 Oxygen Depletion Applications Diffusion Sensor in Space: Constant monitoring of O2 level to ensure leaking nitrogen cylinder does not displace oxygen

42 MRI Application

43 Oxygen depletion extraction systems

44 Chemical storage application Volatile Organic Compounds (VOCs)

45 On behalf of Honeywell Analytics Thank you. Greg Kaufman