VENTILATION

In general, it is a good idea, and in some cases, it’s required under OSHA regulations to provide proper ventilation in the work environments before entry. A forced space ventilation system is required to remove air and atmospheric contaminants like hazardous gases, provide oxygen, and keep the air quality as clean as possible.

Information on space ventilation products can be found on their pages by following the links. For more information on atmospheric hazards, forced air ventilation, gas monitoring, or other worksite safety and equipment questions, consult PK Safety’s website and blog or talk to one of our safety experts. Also check out other work environment gears, including our confined space kits, confined space signs, retrieval systems, and personal protective equipment.

Frequently Asked Questions

How do I ventilate work environments?

Ventilating a confined space involves removing atmospheric hazards like toxic gases by introducing fresh air into the space, removing stale air or contaminants, or a combination of the two. There are two options for confined space ventilation. A forced-air ventilation system uses fresh air, forced in by a fan, to ventilate a work environment. The incoming air displaces contaminants and dilutes the stale or contaminated air already in the space.

Exhaust ventilation uses an exhaust system to remove contaminants like toxic gases at the source. Confined space blowers or exhaust systems are usually attached to a space by way of a duct to help direct the airflow.

How do I calculate the ventilation rate for a work environment?

The size and shape of a confined space, as well as the work being done there with flammable materials and combustible gases, will affect the ventilation requirements. Before you calculate the minimum required ventilation rate, you need to know the size of the space in cubic feet. 

You also need to determine the air changes (number of times the air must be replaced based on legal limits as well as company policy) per hour. Multiplying these two numbers together gets you the total cubic feet per minute (CFM) requirement. 

This result is the minimum rate of space ventilation required for your confined space. An irregularly shaped space will likely require a greater CFM blower to effectively ventilate. 

Turns, corners, bulky equipment, and even the ducts themselves can further restrict airflow, which may impact CFM calculations. You may need to take into account available power sources, how stable those sources are, and other equipment that will be drawing power from those sources.

Why is confined space ventilation important when welding?

Welding in a work environment creates very dangerous conditions that can include a lack of oxygen, fires and heat, hazardous gases, and other toxic substances to be inhaled. Luckily, proper ventilation can help mitigate some of these risks. 

OSHA lays out very specific requirements for welding in confined spaces because of this. If an area lacks natural airflow, welders need to use airline respirators and personal protective equipment. They should also maintain constant communication with outside coworkers (which is also a good idea even if you aren’t welding). 

Have pre-planned rescue and emergency procedures whenever you’re doing any work, and make sure that the air is tested. Also, ensure that there’s a way to shut off dangerous equipment from inside the workspace if possible and that the exit points aren’t blocked.

Should you ventilate before entering a job site?

You absolutely should! Good ventilation helps control fumes, dust, vapors, mists, and other contaminants and atmospheric hazards. It helps to both bring in fresh air and keep dangerous materials to a low enough exposure limit to make the environment safe enough for humans.

Such precautions help provide protection in case more potential hazards are released, remove contaminants that are already in the space, and keep things cool and comfortable.

However, you should also continuously ventilate, monitor, and test the space while work is being done. Conditions in work environments can change suddenly. It’s especially crucial to respond to hazards in a timely manner to avoid anyone getting trapped, seriously hurt, or sick. Keep ventilating a space as long as there are workers inside.

How often should confined space ventilation equipment be inspected and maintained?

Confined space ventilation blowers and ducts should be inspected before each use for damage, blockages, or wear. Additionally, schedule professional maintenance at least annually or according to manufacturer specifications.

Proper maintenance practices are essential for occupational safety, particularly during confined space operations. These approaches help protect workers from air quality hazards and ensure a healthy work environment. Effective ventilation creates a safer atmosphere for all personnel on site.