Updated: Feb 24
EPA 608 Core Chapter 41 (Take full course for free)
This module will look at the different safety precautions that need to follow in the HVAC practices.
1. Oxygen Deprivation
When handling refrigerants, our first priority is always safety. Wearing the correct safety attire is important in preventing frostbite from contact with the refrigerant. But it is only the first step.
Other dangers to HVAC technicians are falls and electric shocks. This is because technicians have to get on ladders to access components and have to work with electrical parts.
But did you know that the number one cause of refrigerant-related deaths is actually oxygen deprivation?
Technicians work with refrigerant gases that are odorless and invisible. So it can be hard to tell refrigerant has leaked.
What ends up happening is that because these refrigerants are denser than oxygen, they sink to the bottom of the room, pushing oxygen to the top. Imagine a lava lamp that is settled. The oxygen you need to survive is floating at the top, and you and the refrigerant are at the bottom.
Without oxygen, you will suffocate. This is why oxygen deprivation is the number one cause of death in handling refrigerants.
If refrigerants are inhaled in high concentrations, they can cause heart irregularities and/or unconsciousness. This is dangerous because if the technician is unconscious, then this can also lead to oxygen deprivation.
For all of these reasons, safety procedures need to be taken seriously.
If refrigerants are released in a contained area, you need to either:
Wear a Self-contained breathing apparatus (SCBA), or
Leave the area
If refrigerants are released in a contained area, normal protection is not sufficient. This includes safety goggles, butyl-lined gloves, and dusk masks.
Self contained breathing apparatus (SCBA) are heavy duty equipment designed to specifically prevent oxygen deprivation. If you cannot locate one, you must leave and evacuate the area.
2. Pressurized Substances
If you are pressurizing equipment, you need to verify the equipment’s allowable test pressure. This design pressure information will be on a nameplate located on the equipment. You should check for the low-side test pressure value.
If you find corrosion on the body of the relief valve, you must replace the valve. The purpose of the relief valve is to protect against too much pressure in the compressor.
If the relief valve is corroded, it will not be able to prevent catastrophic failure in the compressor in the case of too much pressure. That is why the relief valve needs to be replaced if corrosion is found.
When checking for leaks, technicians should never use oxygen or compressed air to pressurize appliances. This is because oxygen or compressed air can explode when mixed with compressor oil or refrigerants.
Oxygen cannot be mixed with oils for this reason. Oxygen also cannot be mixed with any grease, which act like oils.
Recall that the best way to test for leaks is with dry nitrogen. When charging a system with nitrogen, you need to charge through a pressure regulator. This means that you need a relief valve to make sure pressure is not too high.
Prior to pressurizing a system with nitrogen, you should always install a pressure relief valve on the nitrogen cylinder. This acts as a safety measure in case the pressure is too high in the tank.
You will also need to make sure that this relief valve is installed downstream from the pressure regulator.
In this module, we discussed the safety precautions that need to follow while performing the HVAC practices. Safety is always key, and we need to understand potential dangers and proper handling procedures to avoid serious injury or worse.
Next, we will discuss specific procedures and things to be aware of when handling refrigerant cylinders.