Not everyone will think of a fire alarm as a piece of home security equipment, but these detectors are one of the most important aspects of keeping any home safe. Smoke detectors are also used in commercial settings, and in fact, are typically required by commercial building code. Stolen goods can always be recovered by the police, but when irreplaceable items are lost in a house fire, there’s no coming back. If a home should have any security components, a smoke detector should be at the top of that list.
Here are the key differences between a smoke detector and a CO detector:
- Smoke detectors detect the presence of a fire by detecting smoke (or heat)
- CO detectors detect carbon monoxide, which is most commonly caused by poor ventilation with a generator or furnace.
- Smoke detectors are typically placed on the ceiling because smoke rises
- CO detectors can sometimes be placed on a wall or floorboard since carbon monoxide is neutrally buoyant with air.
- Both detect potentially deadly situations and are important to have in any home or building.
How Smoke Detectors Work
The NFPA identifies two major kinds of smoke detectors used in modern homes: the ionization smoke detector and the photoelectric smoke detector – also referred to as an optical smoke detector.
Ionization smoke alarms work by using a small amount of radioactive material. This radioactive material ionizes the air within a chamber inside the detector, causing a current to flow between the two electrically charged plates. When smoke enters this chamber, the particles in the smoke disrupt the flow of the electrical current, and this activates the alarm when the sensor detects that the current is disrupted. Photoelectric smoke detectors work by having a constant light beam inside of the detector. When smoke enters the detector, it deflects the light beam into a light sensor, which triggers the alarm.
Which Type of Smoke Detector is Best?
While each type of detector employs a different means to detect a fire each is highly effective. Unfortunately, one type of sensor is not necessarily better than the other conclusively because each is faster at detecting different types of fires. Ultimately, both types of detectors should give occupants sufficient notice that a fire is present so that they can vacate the premises.
An ionization smoke alarm reacts much more quickly to large, blazing fires, the type that burns fast. However, ionization smoke detectors are slower than photoelectric detectors at sensing fires that begin with long periods of smoldering.
Photoelectric smoke detectors notice these slow, smoldering fires more quickly. Thankfully, it’s not a competition between both types of smoke detectors. The National Fire Prevention Association recommends households use both types of smoke alarm technologies, as it is impossible to predict what type of fire a house will face. Certain companies even produce dual-sensor alarms that combine both technologies into one convenient detector.
Perhaps most important is having a sufficient number of detectors, installing them in the correct locations, and maintaining them properly so that everyone can be assured that they are functioning correctly. This is why it can be important to have a professional fire alarm company or security alarm company design and install the detector system.
What Are the Different Types of Carbon Monoxide Detectors?
Detecting carbon monoxide gas in the home quickly is the most important preventative measure for carbon monoxide poisoning, as the symptoms of the poisoning can oftentimes onset when it’s already too late. The NFPA recommends the use of carbon monoxide detectors, as once a certain amount of carbon monoxide is sensed by the detector, an alarm is set off. There are numerous ways that these alarms can be set off, depending on the type of carbon monoxide detector.
Biometric CO Detectors
The biomimetic sensor style of carbon monoxide detector works thanks to a color-changing gel. This gel inside the detector will change color upon absorbing carbon monoxide, which will then trigger the alarm. A metal-oxide semiconductor has a silica chip, rather than a gel. This chip lowers in electrical resistance when exposed to carbon monoxide, and when this resistance is lowered, an alarm is triggered.
Electrochemical CO Detectors
Electrochemical sensors, as the name implies, are made up of electrodes within a chemical solution. This chemical solution, when exposed to carbon monoxide, will change the electrical current, which then triggers the alarm.
Each type of detector comes with its own strengths. Colorimetric detectors measure buildup over time. Electrochemical sensors are the most sensitive to carbon monoxide, allowing for early response when carbon monoxide is detected. Metal oxide semiconductors have the benefit of not just being carbon monoxide detectors, but also chlorine bleach and silicone.
Modern-day detectors can now detect both smoke and carbon monoxide gas, and differentiate between the two, allowing for extra convenience. It’s recommended to have at least one each floor of the home, attic, and basement included, in addition to the doors near bedrooms and garages. This will help maximize being able to notice when an outbreak of carbon monoxide gas occurs in the home.
The History of the Smoke Detector
The modern smoke detector can trace its roots to the late 1930s. Walter Jaegar, frustrated that his latest invention, a poison gas sensor, wasn’t working as he had hoped. He had envisioned the device to work when gas entering the sensor would alter the electric current in the circuit of the device, but the concentrations of gas didn’t trigger the desired effect. As the story goes, Jaegar lit a cigarette and noticed the instrument recorded a drop in current, and this discovery of smoke particles triggering this current drop led to the modern-day smoke detector.
It wasn’t until 1951 that ionization smoke detectors would make it to the United States, only used in large industrial facilities due to concerns with size and cost. The average consumer would have a simple fire detector in their home, which only reacted to high temperatures rather than detecting smoke. However, the temperature of the room as a measure for alarm was flawed in numerous ways; by the time the temperature reaches a level that would trigger the alarm, a room could fill with smoke, or fire could spread, and studies were actively showing that smoke detectors noticed fires more quickly than heat detectors. Thankfully, in the 1970s, smoke alarms became much smaller and more affordable for consumers, only needing the power of a 9-volt battery to run.
History of Carbon Monoxide Detection
Carbon monoxide is a particularly dangerous gas because humans can not detect it with their senses. Importantly, CO gas is odorless and colorless and also lacks any taste or feel. CO gas works in the human body by displacing oxygen, which is critical to life. By the time most people realize that something is wrong or that they have CO poisoning it is often too late. Carbon monoxide is also very prevalant since any type of combustion can generate it. Common sources of poisoning in current times are generators run indoors with inadequate ventilation, a furnace that does not vent properly, or coal or woodstoves used to heat homes.
Since its discovery in the late 1700s, scientists have learned more and more about the deadly nature of carbon monoxide gas. As carbon monoxide poisoning can be caused by a variety of household appliances and heating systems, the need for detecting the poison gas before it can cause any harm became more and more important.
Early carbon monoxide detectors were very crude and rudimentary. In 1925, sanitation workers would manually crush glass containers filled with a variety of chemicals in order to detect carbon monoxide inside confined spaces like manholes. Following the success of the home smoke detector, BRK Electronics went on to develop the first mainstream carbon monoxide detectors, released in the mid-1990s. When deployed properly carbon monoxide detectors are a critical piece of life safety equipment that every home and building should have.
Smart Homes and Smoke & Carbon Monoxide Detectors
Modern smoke and carbon monoxide detectors can also be “smart detectors”, or detectors that connect to a cell phone app, or even to a house’s greater security system. These smart detectors add an extra layer of convenience to the home security experience. By connecting these detectors directly into the home security system, residents have all of their security products in one centralized base. This can even prove to save lives in some situations – a family receiving a warning of carbon monoxide in their home while they’re already out of the house will know before entering the house, dramatically decreasing the chance of exposure and allowing them to report it to the authorities to clear out the gas sooner than if they had waited until they got home to call it in. These smart devices will send notifications to your phone or tablet when the alarms go off, allowing you to know right as it happens.
It’s truly spectacular that the dangers of poisonous gases and fires can be circumvented with the use of these carefully crafted alarms. A simple alarm system to warn people of dangers within the home, whether it be an electrical fire or a heating failure dispensing poisonous gas into the home, is a necessity in home security. Security begins from inside the home, from the accidental dangers, the dangers that are unpredictable and can happen any time. Whether the simplest alarm, or a complex system of alarms all working together within a single security system, having carbon monoxide and smoke detectors is key to owning a safe home.