A positive pressure enclosure, also known as welding habitats or hot work habitats, is a chamber used to provide a safe work environment for performing hot work in the presence of explosive gases or vapours. They are used most often in conjunction with the need for welding, and are often associated with the offshore oil industry.
A positive pressure enclosure works by providing a constant inflow of breathable atmosphere, which in turn causes gas to continuously leak out of the chamber. This outflow of gases prevents the ingress of explosive gases or vapours which are often present in such work locations. This constant outflow of gases from the chamber also serves to cleanse the air within of the undesirable gaseous by-products of the welding process. Most commercial versions of positive pressure enclosures are referred to by their manufacturers as habitats.
The qualities of good Indoor Air Quality should include comfortable temperature and humidity, adequate supply of fresh outdoor air, and control of pollutants from inside and outside of the Habitat. Indoor air quality (also called "indoor environmental quality") describes how inside air can affect a person's health, comfort, and ability to work. It can include temperature, humidity, lack of outside air (poor ventilation), mold from water damage, or exposure to other chemicals. Currently, OSHA has no indoor air quality (IAQ) standards but it does provide guidelines about the most common IAQ workplace complaints, the habitat technician need to provide daily practical solutions to ensure the worker inside habitat is safety and healthy.