Craig Wolfe
Toxalert International, Inc.
Mound, MN
• Codes & Standards •
• Technologies & Locating
Sensors •
• System Maintenance •
Codes and Standards
ANSI/ASHRAE 15-2007
International Mechanical Code® (IMC)
2006
International Fire Code® (IFC) 2006
Codes and Standards
ANSI/ASHRAE 15-2007
Safety Standard
for
Refrigeration Systems
ASHRAE 15-2007
 Forward
“Care should be taken to avoid stagnant pockets of
refrigerant vapors by proper location of ventilation
inlet and exhaust openings. All machinery rooms
are required to have detectors that will activate an
alarm and mechanical ventilation at a value not
greater than the corresponding TLV-TWA.”
“Informative Appendix I provides guidance on
integrating the requirements of this standard with
occupational health & safety programs.”
ASHRAE 15-2007
 8.11 Refrigerating Machinery Room, General
Requirements.
 8.11.2.1 “Each machinery room shall contain a detector, located
in an area where refrigerant from a leak will concentrate, that
actuates an alarm & mechanical ventilation…at a value not
greater than the corresponding TLV-TWA (or toxicity measure
consistent therewith). The alarm shall annunciate visual &
audible alarms inside the refrigerating machinery room &
outside each entrance to the refrigerating machinery room.
The alarms required in this section shall be of the manual
reset type with the reset located inside the refrigerating
machinery room…..”
ASHRAE 15-2007
 8.11.6 “….Combustion equipment shall not be
installed in the same machinery room with
refrigerant-containing equipment except under
one of the following conditions:
(a) combustion air is ducted……
(b) a refrigerant detector,…is employed to
automatically shut down the combustion process in
the event of refrigerant leakage…….”
ASHRAE 15-2007
 8.12 Machinery Room, Special Requirements.
 8.12.i. “Remote control of mechanical equipment in
the refrigerating machinery room shall be provided
immediately outside the machinery room door
solely for the purpose of shutting down the
equipment in an emergency. Ventilation fans shall
be on a separated electrical circuit and have a
control switch located immediately outside the
machinery room door.”
Codes and Standards
2006 IMC
 1101.6 General.
“Refrigeration systems shall comply with the
requirements of this code and, except as modified
by this code, ASHRAE 15. Ammonia-refrigerating
systems shall comply with this code and, except as
modified by this code, ASHRAE 15….”
2006 IMC
 1105.3 Refrigerant detector.
“Refrigerant detectors in machinery rooms shall be
provided as required by Sections 606.8 of the
International Fire Code.”
2006 IMC
 1106.5 Remote controls.
“Remote control of the mechanical equipment and
appliances located in the machinery room shall be
provided as required by Sections 606.8 of the
International Fire Code.”
2006 IMC
 1106.5 Remote controls.
 1106.5.1 Refrigerant system.
“A clearly identified switch of the break-glass type
shall provide off-only control of electrically
energized equipment and appliances in the
machinery room, other than refrigerant leak
detectors and machinery room ventilation.”
2006 IMC
 1106.5 Remote controls.
 1106.5.2 Ventilation system.
“A clearly identified switch of the break-glass type
shall provide on-only control of machinery room
ventilation fans.”
Codes and Standards
2006 IFC
 606.8 Refrigerant detector.
“Machinery rooms shall contain a refrigerant
detector with an audible and visual alarm. The
detector, or a sampling tube that draws air to the
detector, shall be located in an area where
refrigerant from a leak will concentrate. The alarm
shall be actuated at a value not greater than the
corresponding TLV-TWA values shown in the
International Mechanical Code for the refrigerant
classification. Detectors and alarm shall be placed
in approved locations.
2006 IFC
 606.9 Remote controls.
“Remote control of the mechanical equipment and
appliances located in the machinery room shall be
provided at an approved location immediately
outside the machinery room and adjacent to its
principal entrance.”
2006 IFC
 606.9 Remote controls.
 606.9.1 Refrigerant system.
“A clearly identified switch of the break-glass type
shall provide off-only control of electrically
energized equipment and appliances in the
machinery room, other than refrigerant leak
detectors and machinery room ventilation.”
2006 IFC
 606.9 Remote controls.
 606.9.2 Ventilation system.
“A clearly identified switch of the break-glass type
shall provide on-only control of machinery room
ventilation fans.”
Sensor Technologies
Monitoring Systems
Locating Sensors
Sensor Technology
Common Types Of Refrigerant Leak
Sensors
 Metal Oxide Semiconductor (MOS)
 Non Dispersive & Photoacoustic Infrared
Sensor Technology
MOS SENSOR
Heater Coil
Sensor Element
Pin
Sensor Technology
Infrared Sensor
LIGHT FILTERS
SENSOR CHAMBER
LIGHT
DETECTOR
INFRARED
LIGHT
SOURCE
SIGNAL
PROCESSOR
Leak Detection Systems
Sampling Systems
&
 Electronic/Diffusion Systems

Leak Detection Systems
Sampling System
CONTROLLER
DRAW
EXHAUST
LINE
SENSOR
PUMP
SOLENOID
VALVES
TUBING
SAMPLE POINT FILTERS
Leak Detection Systems
Electronic/Diffusion System
CONTROLLER
REMOTE SENSORS
Leak Detection Systems
 Features
 Multi-Stage Control
 LCD Display of Refrigerant Concentration
 Visual Indicators for
Power On
 Stage of Activation
 Fault
 Fan Auto/Purge Switch
 Audible Alarm With Silence Switch
 Manual/Auto Warning Stage Reset Switch

Leak Detection Systems
 Options
 Analog output (4-20mA or 0-10vdc)
 Integral strobe
 RS 232/485 communications for modbus, BACnet©
Leak Detection Systems
Typical Control
CONTROLLER
120VAC
FIRST
STAGE
SECOND
STAGE
FAULT
Locating Sensors
Guide lines to properly locating a refrigerant sensor
in an equipment room is:
(a) determining the airflow pattern in the room;
(b) remembering that occupant safety is the primary
motive for installing the sensor; and
(c) All commonly used refrigerants except ammonia
are 3 to 5 times heavier than air.
Locating Sensors
As a Minimum General Guide
Locate sensors so no chiller is more than 50 ft. from
a sensor.
Locating Sensors
AIR INTAKE
REFRIGERANT SENSOR
CHILLER
REFRIGERANT LEAK
MONITOR PANEL
CHILLER
CHILLER
CHILLER
EXHAUST
Locating Sensors
AIR INTAKE
REFRIGERANT SENSOR
CHILLER
REFRIGERANT LEAK
MONITOR PANEL
CHILLER
CHILLER
CHILLER
EXHAUST
Locating Sensors
REFRIGERANT LEAK
MONITOR PANEL
AIR INTAKE
REFRIGERANT SENSOR
CHILLER
CHILLER
CHILLER
EXHAUST
Locating Sensors
REFRIGERANT LEAK
MONITOR PANEL
AIR INTAKE
REFRIGERANT SENSOR
CHILLER
CHILLER
CHILLER
EXHAUST
Leak Monitoring System
STROBE/REM
HORN/REM
TOX-REFRIG
PANEL
CH-1
SCBA
TOX-REFRIG/ANA
CH-2
ALM/REFRIG
TOX-REFRIG/ANA
BOILER
STROBE/REM
HORN/REM
Maintenance
ASHRAE Standard 15
 11.6.3 Periodic tests.
“Detector(s), alarm(s), and mechanical ventilating
systems shall be tested in accordance with
manufacturers’ specifications and the
requirements of the jurisdiction having authority.”
Maintenance
2006 IMC
 1109.1 Testing required.
“The following emergency devices and systems shall
be periodically tested in accordance with the
manufacturer’s instructions and as required by the
code official:

1109.1.4 “Detection and alarm systems.”
Maintenance
2006 IFC
 606.6.1 Periodic testing.
“The following emergency devices and systems shall
be periodically tested in accordance with the
manufacturer’s instructions and as required by the
fire code official:

606.6.1.4 “Detection and alarm systems.”
Maintenance
MOS/Diffusion System Periodic
Maintenance
 Sensor calibration
Maintenance
Sampling Infrared System
Periodic Maintenance
 Sensor calibration
 Sample point filters
 Internal filter
Maintenance
Calibration kit
Questions?