Smoke detectors: types, operation, and installation

Smoke detectors: operation and installation

Smoke and gas sensors are equipment that prevent potential risks that can occur within a home due to the presence of toxic or flammable gases. They detect any gas emissions or the presence of smoke. Gas detectors can indicate the presence of various types of gases, such as butane gas, methane gas, or natural gas at dangerous levels.

Optical smoke detectors are safety devices that emit a signal upon detecting excessive smoke in the air. They have a lens installed that detects visible smoke. This process can occur through the darkening of the air or by detecting its dispersion. There are two types:

• Infrared ray, which have an emitting device and a receiving device. The receiving device obtains a very small fraction of light from the emitting device after the space between them has darkened, which is why the alarm is activated.
• Point-type. Both the receiving and emitting devices are located in a single chamber, although separated by a screen. When smoke enters the chamber, the light beam refracts towards the receiver and triggers the alarm.

Since smoke tends to rise, this type of device has a fixed installation on the ceiling that increases its efficiency and performance. They operate through an acoustic signal that is activated when smoke presence is confirmed. Maintenance involves checking the batteries every six months and performing periodic cleaning since residues and dust can accumulate in the chamber.

Gas detectors are devices that detect whether there is gas in an indoor space, activating a visual or audible signal. In some cases, they are connected to the gas system to deactivate automatically when levels exceed recommended limits. They operate connected to the electrical network, and similar to smoke detectors, they are placed on the ceiling to optimize their performance. They can identify several types of gases such as butane, propane, or methane. If the concentration of gas in the environment is between 3% and 20%, the alarm is triggered.

Humidity and CO2 sensors in ventilation systems

Humidity is the most crucial factor in calculating how much air needs to be extracted from a dwelling. For this reason, extraction is performed in the damp areas of the interior, preventing unwanted condensation. Extraction will continuously operate at a minimum flow position to keep the building in healthy conditions. The extractor has a humidity sensor that detects increases in relative humidity, for example, between 5% and 10%. The extracted air flow will increase as long as the humidity level persists.

CO2 is the most appropriate indicator to signal the occupancy level of people and their metabolic activity in a space. CO2 sensors take measurements in the occupied areas of the home. Only when one or more people are present, the air in the room will become contaminated. The sensor detects this variation in air composition and activates the ventilation system, which will start adjusting the flow of fresh air as needed.