Top 5 Air Quality Monitors for the Home (2024 update)

Carbon Dioxide Monitor, Carbon Monoxide Detector, CO Detector, CO2 Monitor, Gas Leak Detector, Low Level CO Detector, Particulate Matter PM2.5 -

Top 5 Air Quality Monitors for the Home (2024 update)

Gas detectors are essential for ensuring a healthy and safe home environment. The three most crucial detectors for residential use are carbon dioxide (CO2) monitors, carbon monoxide (CO) detectors, and particulate (dust) detectors, which collectively address 95% of indoor air quality issues. When evaluating the air quality in your home, it is highly recommended to use gas detectors that provide raw ppm or % volume values of the target gas. This allows for an objective comparison to outdoor air quality values and government exposure recommendations from OSHA, NIOSH, and ACGIH. Gas detectors that offer arbitrary air quality index values should be avoided, as they do not provide the necessary precision for accurate assessment and decision-making regarding indoor air quality improvements.



  • A plethora of gas detectors are available to detect most toxic gases.
  • Affordable prices and availability.
  • Problems usually can be narrowed to three key toxins: CO, CO2, and particulate (dust/smoke).
  • Low cost Air Quality Monitor for Home are available.
  • Some low cost, non-specific sensors on the market confuse users.
  • Cheap and inaccurate products dominate marketplaces, such as, and confuse users.
  • Toxic gas measurements can be tricky. Never rely on your nose.
  • Low cost Air Quality Monitor for Home are abundant but may break early and will not last.

Why Detect Air Quality in the Home?

The main purpose of detecting indoor air quality is:

  • To ensure home occupants are breathing healthy air. This is especially important for the young, elderly, and those with pre-conditions.
  • To take corrective measures if an indoor air quality problem exists.
  • To track the problem gas(es) that may inadvertently enter the home from a neighbor, appliance, or the outdoors.
  • To ensure OSHA or NIOSH occupational exposure limits are met.
  • To prevent adverse health reactions, especially for those with hypersensitivities. Examples include headaches from low levels of carbon monoxide or respiratory problems from ammonia coming from pet urine.

How Is Bad Air Quality Produced in the Home?

There are many sources of dangerous and toxic gases that contributes to poor air quality. A comprehensive list of problematic gas generation and possible sources is listed here:

  • Carbon dioxide accumulation from home occupant exhalation.
  • Carbon monoxide from oven, stovetop, boiler, or other fuel-burning appliances. Others sources include carbon monoxide from vehicles left running in the garage, portable generators operating within or close to the home, and poorly installed or faulty heaters (i.e., cracked heater exchange).
  • Dust, smoke, and particulate accumulation from cigarette smoke, cannabis, vaping, or cooking.
  • Ozone accumulation produced from laser printing.
  • Ammonia accumulation produced from pet urine. This chemical can also accumulate in the home after cleaning with ammonia-based cleaners.
  • Refrigerant gas, such as freon, from refrigerant leaks.
  • Formaldehyde and VOCs accumulation as a result of off-gassing from carpets, furniture, and synthetic objects within the home.
  • Radon accumulation and leaking into the home.
  • Sulphuryl fluoride accumulation or residue after a home fumigation.
Air Quality Monitor for Home

1. Best Carbon Monoxide Detector

A carbon monoxide detector is imperative.

In some cities and states, it is actually required by law to have a carbon monoxide detector within your home, and sometimes, several are required to fulfill local and state code.

In addition to a regular CO detector, we highly recommend the Forensics Detectors low level carbon monoxide detector.

Low level carbon monoxide detectors offer another level of protection beyond a standard CO meter purchased from Home Depot (UL2034 type). A low level CO detector is typically able to alarm home occupants much faster and at lower carbon monoxide levels.

For example, the FORENSICS low level CO detector triggers an audible alarm when CO is detected > 25 ppm, whereas the standard CO detector alarms at 70 ppm.

According to the Cleveland Clinic, the symptoms of low levels of CO exposure include:

  • Mild headache
  • Mild nausea
  • Shortness of breath

2. Best Carbon Dioxide Monitor

The best carbon dioxide monitor is the Forensics Detectors carbon dioxide monitor.

Since the COVID-19 pandemic, carbon dioxide monitoring has been a hot topic as high CO2 levels come with an increased risk of airborne pathogen infection. High CO2 levels act as a good indicator for stale air. This typically suggests poor ventilation and a low air exchange rate.

Carbon dioxide is mostly generated from the exhalation of home occupants. This exhalation can accumulate to dangerous levels. In the most extreme cases, CO2 can displace oxygen and lead to asphyxiation.

Since CO2 is odorless and does not cause irritation, it is considered to have poor warning properties. This is why CO2 monitoring is so important.

3. Best Dust Detector

The best particulate PM2.5 detector is the Forensics Detectors PM2.5 Detector, perfect for smoke, dust, and particulate matter.

A particulate detector is similar to a very sensitive smoke detector, but with the advantage of providing earlier warning to airborne particulate that can penetrate the lungs and bloodstream. Smoke, particulates, and dust are mostly referred to as Particulate Matter (PM).

Detecting particulates is an excellent indicator for poor indoor air quality coming as a result of the outdoor environment. This can be seen in cities where PM is a problem or rural areas where dust and wildfires may contribute to poor air quality.

4. Best Sewer Gas Detector

The best sewer gas detector is the FD-91 (RED). The people have spoken as it is highly ranked on

This unit is used by plumbers, HVAC technicians, and boiler technicians to find natural gas and sewer gas leaks.

5. Best Natural Gas Leak Detector

The best detector to detector a home kitchen gas leak is to use a natural gas leak detector. This will ensure all pipes, piping, connections and appliances are correct and not leaking any natural gas.

6. Best Formaldehyde Detector

The best formaldehyde detector is a specific and NIST-calibrated formaldehyde detector, like the FD-90A-C2HO. This is a handheld unit that is able to detect down to 0.01 ppm of formaldehyde. 

There are many so-called formaldehyde detectors on the market. These low cost products made to fool non-technical customers that seek a cheap solution to their air quality problems. Be aware of these devices and don't waste your money. The Forensics Detector unit is a properly calibrated to NIST Traceable sources, meaning you can be assured that it is accurate.

7. Best Smoke Smells (Cigarette, Weed, and Grass)

Smoke is made up of small carbon particles, sometimes referred to as particulate matter. They are commonly distinguished by diameter size. For example, PM2.5 particles have a diameter less than 2.5 microns and PM10 particles measure less than 10 microns across.

Particulate matter is a problem for outdoor environments, where PM is produced from industrial emission and diesel engines. Particulate matter can also infiltrate the indoors, meaning that a high-quality HVAC filter is highly recommended.

Indoor dust, cooking, and other sources can contribute to indoor particulate matter. In addition, PM can also contain aromatic components, such as smells coming from cigarette and weed smoke. 

8. Best Cigarette and Weed Smoke Detector

The best method to detect weed smoke is to have a very sensitive device, specifically made for cigarette and cannabis smoke.

A particulate matter PM2.5 is a great option.

These detectors use light absorption and scattering to determine trace amounts of smoke in the air that will trigger a warning or alarm.

9. Best Radon Detector

The best radon detector, as determined by customer ratings on, is the Corentium Home Radon Detector by Airthings.

10. Best Detector for Pet Dander and Pollen

There is no reliable pet dander or pollen detector that we can recommend.

Pet dander is made of microscopic dead skin particle, fur, or hair from dogs or cats. This dander is airborne but eventually settles to the ground. It is not a gas, so cannot be detected by a gas meter.

Similarly, pollen is not a gas and cannot be monitored by a gas detector. Pollen is made of small microscopic grains that are suspended in the air. 

Unfortunately, there are no handheld, battery-operated, simple, and affordable pet dander or pollen detectors on the market.

Air Quality Monitor for Home

Should I Place a CO Detector in My Garage or Boiler Room?

Yes you should.

Many vehicles are left on in the garage that can create a very dangerous situation. Carbon monoxide can infiltrate the garage, then seep into the home. 

This is a problem for older people that simply forget and leave the vehicle running. In addition, keyless car technology has added to the problem.

Also, boilers are common producers of carbon monoxide spillage in a boiler room.

For garages, we recommend the Forensics Detectors carbon monoxide wall mount detector. It comes with a relay that can be connected to control your garage door. If your car is left running, the CO monitor will alarm and open the garage door to ventilate the polluted garage space.

Is There a Gas Detector That Can Find a Dead Rat or Critter?

No, detecting the aromas of a dead rat or critter cannot be achieved with a gas detector. These smells are made up of complex aromatic gas compounds that cannot be detected using a regular gas detector.

Is My Printer Producing Ozone Gas in My Home?

Yes, laser copiers and printers do produce ozone. The challenge is to understand how much ozone is produced and how it accumulates in your home. For example, if you are printing continuously, have poor air ventilation, and in a small room, then ozone will accumulate and may increase to dangerous concentrations.

Ensure your printer is in a large and well-ventilated room.

Workplace printer rooms are also problematic and may generate higher levels of ozone.

We recommend using a handheld low level ozone detector to check levels, such as the Forensics Detectors FD-90A-O3-LOW.

Can I Detect a Home Refrigerant Leak With a Gas Detector?

Yes you can.

You need to purchase a Freon Refrigerant Gas Leak Detector. A freon gas leak detector is sensitive to refrigerant gases, such as freon and R-410A.

Can I Detect Ammonia From a Household Cleaner Such as Windex?

Yes you can.

An ammonia detector will detect accumulation from an ammonia-based cleaner. However, just like ozone, be aware that the human nose is very sensitive at detecting aromatic gases. Initially, your nose may actually do a better job than your gas leak or ammonia detector. 

With that being said, a detector is more reliable since the human nose is subject to olfactory fatigue. Over time, the nose loses its sensitivity to the aromatic gas being detected, making it a poor objective gas detector.

For ammonia, we recommend our basic ammonia detector.

Air Quality Monitor for Home

What Is the Best Cat or Dog Urine Detector (Ammonia)? 

Dog or cat urine can be detected with an ammonia gas detector.

However, factors such as your home ventilation, room volume, and air exchange rates will determine the actual concentration of ammonia. Do not depend on your nose to provide an objective ammonia gas concentration. Many factors are at play.

Will a Carbon Monoxide Detector Detect a Gas Leak?

No, it will not detect a gas leak.

A carbon monoxide detector can only detect CO gas. Instead, use a gas leak detector that is sensitive to combustibles such as methane (natural gas) and propane to detect a gas leak.

Where Do You Place a Gas Leak Detector in a House?

Place your gas detector as close as possible to the stovetop.

The most common gas leak will be from your stovetop when users accidentally leave the stovetop.

Another common occurrence is when the flame goes out due to water overboiling, which leaves the gas running.

Can Mold Be Detected by a Gas Detector?

No, it cannot.

A gas detector cannot detect mold because it is not a gas. Mold is a type of fungi that is suspended in the air and requires other techniques to be reliably detected. 

Final Words

Gas detectors are essential for maintaining a safe and healthy home environment. The three most important detectors for residential use are carbon dioxide (CO2) monitors, carbon monoxide (CO) detectors, and particulate (dust) detectors, which collectively address 95% of indoor air quality issues. When assessing indoor air quality, it is crucial to use gas detectors that provide raw ppm or % volume values of the target gas, allowing for objective comparisons to outdoor air quality values and government exposure recommendations from OSHA, NIOSH, and ACGIH. Gas detectors with arbitrary air quality index values should be avoided, as they do not assist in pinpointing specific problems. Moreover, relying on your sense of smell for gas assessment is not recommended, as some gases like CO and CO2 are odorless, while others such as NH3 and H2S have distinct odors. Utilizing accurate and reliable gas detectors is the best way to ensure a safe and healthy indoor environment.

    About The Author

    Dr. Kos Galatsis ("Dr.Koz") is the President of FORENSICS DETECTORS, where the company operates from the scenic Palos Verdes Peninsula in Los Angeles, California. He is a subject matter expert on gas sensor technology, gas detectors, gas meters, and gas analyzers. He has been designing, building, manufacturing, and testing toxic gas detection systems for over 20 years.

    gas detector expert

    Every day is a blessing for Dr. Koz. He loves to help customers solve their unique problems. Dr. Koz also loves spending time with his wife and his three children going to the beach, grilling burgers, and enjoying the outdoors.

    Read more about Forensics Detectors here.

    Phone: +1 424-341-3886