There are situations in which a building designer wishes to use non-electrical exit signs. In emergency situations, power is often unavailable, and non-electrical exit signs may also provide greater safety in situations where electrical exit signs might contribute to the possibility of fire. There are two basic kinds of non-electrical exit signs: self-luminous exit signs and photoluminescent exit signs.
Self-luminous, or radio-luminescent, exit signs use a non-electrical glass tube filled with tritium gas to provide light. The tube is coated with phosphor, a phosphorescent substance that absorbs light and re-emits it. Tritium gas provides low radiation that reacts with the phosphor coating to create light. Because of this chemical reaction, self-luminous exit signs can provide light without the use of electricity. Self-luminous exit signs are an excellent choice for energy efficiency because they use no electricity, and they also provide reliable guidance toward exits in cases of emergency where no electricity is available, making them a great safety tool as well.
Photoluminescent exit signs have become increasingly popular in the last few years because of their safety and reliability. In fact, more stringent safety code regulations in some areas are now requiring the use of photoluminescent exit signs. Photoluminescent exit signs are coated in a substance that absorbs energy from the ambient lighting in a room and then emits this energy as light when electrical lights fail. Just like self-luminous exit signs, photoluminescent exit signs are extremely energy efficient because they don’t require any electricity other than the electricity already being used to run the building’s regular light sources.
The number one reason to use non-electrical exit signs is their ability to increase building safety. In emergency situations, electrical power is often lost, and non-electrical exit signs can provide direction for evacuation even if battery-powered backup lights fail. Non-electrical exit signs are also an excellent choice for hazardous areas where flammable substances are being used. Electrical lighting may ignite flammable substances, increasing the risk of explosion or fire. Non-electrical exit signs remove this risk, increasing safety in hazardous areas. Because energy efficiency and safety are two primary concerns for building designers, non-electrical exit signs are an essential consideration for all of today’s public spaces.