According to EPA's test topics on ASHRAE Standard 15, what sensor is needed in a chiller equipment room…

Safety · EPA 608 Type III. The correct answer, and the reasoning behind it.

ASHRAE Standard 15 equipment-room requirements and refrigerant sensors.

The question

According to EPA's test topics on ASHRAE Standard 15, what sensor is needed in a chiller equipment room whatever refrigerant is used?

• AA carbon monoxide detector
• BAn oxygen-deprivation sensorCorrect answer
• CA smoke detector
• DA humidity sensor

Why “An oxygen-deprivation sensor” is correct

EPA's topic list states that ASHRAE Standard 15 equipment rooms need an oxygen-deprivation sensor with all refrigerants, so that is the answer on the 608 test. The wording comes from the 1992 edition of the standard. Since 1994, Standard 15 has instead required a refrigerant detector in every machinery room that sounds an alarm and starts ventilation at or below the refrigerant's exposure limit (now the Standard 34 OEL), which an oxygen sensor alone cannot do.

Source: EPA: Test Topics; ASHRAE Interpretation IC 15-1992-11 (oxygen sensor wording, 1994); ASHRAE 15-2016 Addendum c (detector set point at OEL)

Why the other answers are wrong

• A carbon monoxide detector — Carbon monoxide comes from combustion, not refrigerant leaks.
• A smoke detector — Smoke detectors do not warn of refrigerant displacing oxygen.
• A humidity sensor — Humidity sensors do not protect workers from refrigerant leaks.

Practice more of this

More EPA 608 Type III practice questions, or see every EPA 608 practice test.