HVAC Safety Practices 4 — Questions and Answers
Question 1: What is the maximum fill level (by weight) allowed when filling a refrigerant recovery cylinder?
- 100% of the cylinder's rated capacity
- 80% of the cylinder's rated capacity (Correct answer)
- 90% of the cylinder's rated capacity
- 70% of the cylinder's rated capacity
Correct answer: 80% of the cylinder's rated capacity
Recovery cylinders must not be filled beyond 80% of their rated capacity to allow for liquid refrigerant expansion with temperature changes.
Question 2: A technician is servicing a rooftop unit during a lightning storm. What is the safest course of action?
- Continue working but avoid touching metal components
- Descend from the roof and wait for the storm to pass before resuming (Correct answer)
- Work faster to complete the job before the storm worsens
- Stay low and use rubber-handled tools only
Correct answer: Descend from the roof and wait for the storm to pass before resuming
Rooftops are extremely dangerous during lightning storms due to exposure height and proximity to HVAC equipment that can attract lightning strikes.
Question 3: Which type of respirator is required when working in an area where refrigerant concentrations may exceed IDLH (Immediately Dangerous to Life or Health) levels?
- An N95 particulate filter respirator
- A half-face air-purifying respirator with organic vapor cartridges
- A self-contained breathing apparatus (SCBA) or supplied-air respirator (Correct answer)
- A full-face air-purifying respirator
Correct answer: A self-contained breathing apparatus (SCBA) or supplied-air respirator
IDLH concentrations require a SCBA or supplied-air respirator because air-purifying respirators cannot provide adequate protection at such high concentrations.
Question 4: What safety information must HVAC technicians review before handling any new chemical, including refrigerants and cleaners?
- The manufacturer's color coding system
- The Safety Data Sheet (SDS) for that specific chemical (Correct answer)
- A general chemical safety poster
- The equipment service manual only
Correct answer: The Safety Data Sheet (SDS) for that specific chemical
The Safety Data Sheet (SDS) provides chemical-specific hazard information, safe handling procedures, PPE requirements, and emergency response guidance.
Question 5: An HVAC technician is asked to service a split system in a confined crawlspace. Which atmospheric hazard should be tested for BEFORE entering?
- Carbon dioxide levels only
- Oxygen deficiency, flammable gases, and toxic gases (Correct answer)
- Temperature and humidity only
- Only refrigerant concentration
Correct answer: Oxygen deficiency, flammable gases, and toxic gases
Confined space entry requires testing for oxygen deficiency, flammable/explosive gases, and toxic gases before any worker enters.
Question 6: Why is it dangerous to heat a refrigerant cylinder with an open flame to increase pressure for charging?
- It contaminates the refrigerant with combustion byproducts
- It can cause the cylinder to over-pressurize, rupture, or explode (Correct answer)
- It changes the refrigerant's chemical composition
- It causes the cylinder valve to seize
Correct answer: It can cause the cylinder to over-pressurize, rupture, or explode
Applying open flame to a refrigerant cylinder dramatically increases internal pressure beyond safe limits, creating a risk of catastrophic cylinder failure.
Question 7: When installing a new HVAC system that requires brazing in a space with existing insulation, what precaution must be taken to prevent fire?
- Work quickly so the insulation does not have time to ignite
- Use a heat shield or wet cloth to protect surrounding materials and have a fire watch (Correct answer)
- Spray the insulation with water immediately after brazing
- Remove insulation only within 1 inch of the work area
Correct answer: Use a heat shield or wet cloth to protect surrounding materials and have a fire watch
A heat shield or wet cloth protects flammable surrounding materials, and a fire watch ensures any smoldering materials are caught after the torch is extinguished.
HVAC Safety Practices 4
What is the maximum fill level (by weight) allowed when filling a refrigerant recovery cylinder?