Can Carbon Monoxide Come From an Air Conditioner? Unveiling the Facts

The simple answer is no, air conditioners themselves do not produce carbon monoxide (CO). However, under certain circumstances, particularly involving connected or nearby fuel-burning appliances, an air conditioner can inadvertently contribute to the dangerous accumulation of CO in a home.

Understanding the Source of Carbon Monoxide

Carbon monoxide is a colorless, odorless, and tasteless gas produced by the incomplete burning of fuels such as natural gas, propane, gasoline, wood, and oil. It is a deadly poison because it displaces oxygen in the bloodstream, leading to hypoxia and potentially death. Common sources of CO in a home include:

• Furnaces
• Water heaters
• Gas stoves and ovens
• Fireplaces
• Generators
• Vehicles running in an attached garage

The dangers of CO poisoning are widely known, emphasizing the critical importance of carbon monoxide detectors in every home.

How Air Conditioners Indirectly Contribute to CO Poisoning

While an air conditioner itself doesn’t generate CO, it can play a role in the following ways:

• Negative Pressure: Air conditioners can create a negative pressure environment within a home. This means the air conditioner is pulling air out of the house, potentially drawing exhaust fumes from improperly vented or malfunctioning fuel-burning appliances back into the living space. This is especially problematic if the furnace or water heater shares the same ventilation system or is in close proximity to the air conditioning unit.

• Improper Venting: If a fuel-burning appliance is improperly vented (e.g., a blocked chimney or a disconnected flue pipe), the air conditioner can circulate the CO throughout the house more effectively. Even small amounts of CO leaking from a faulty appliance can become concentrated and dangerous as the air conditioner recirculates it.

• Poor Maintenance: Neglecting routine maintenance on both the air conditioner and fuel-burning appliances increases the risk. Dirty air filters in the air conditioner can exacerbate the negative pressure issue, and unmaintained furnaces or water heaters are more prone to incomplete combustion, resulting in higher CO emissions.

• Sealed Homes: Modern homes are often built to be highly energy-efficient, which means they are tightly sealed. While this helps conserve energy, it can also trap CO inside, making the problem even more dangerous if a source of CO is present. In these “tight homes,” the effect of the air conditioner creating negative pressure is amplified.

Mitigating the Risks: Prevention is Key

The key to preventing CO poisoning related to air conditioners is to ensure all fuel-burning appliances are properly installed, maintained, and vented. Regular inspections by qualified HVAC technicians and thorough checks of all venting systems are essential. The use of carbon monoxide detectors on every level of the home and near sleeping areas is a vital safety measure.

Frequently Asked Questions (FAQs)

What specific type of air conditioner poses the highest risk related to CO?

Generally, central air conditioning systems are more likely to contribute to negative pressure issues compared to window units or ductless mini-splits. This is because central air systems typically move a larger volume of air, potentially creating a greater vacuum effect. However, any air conditioning unit can indirectly contribute if a CO source exists and ventilation is inadequate.

How often should I have my fuel-burning appliances inspected?

Annual inspections by a qualified HVAC technician are highly recommended for all fuel-burning appliances, including furnaces, water heaters, and fireplaces. Regular maintenance can identify potential problems before they lead to dangerous CO leaks.

Where should I install carbon monoxide detectors in my home?

Install CO detectors on every level of your home, including the basement, and outside each sleeping area. Follow the manufacturer’s instructions for proper placement, as some detectors should be mounted on the wall while others should be placed on the ceiling.

What are the symptoms of carbon monoxide poisoning?

Symptoms of CO poisoning can mimic the flu and include headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. In severe cases, CO poisoning can lead to loss of consciousness and death. If you suspect CO poisoning, immediately evacuate the premises and call 911.

Can I use a portable generator indoors if my air conditioner is running?

Never operate a portable generator indoors or in an attached garage, even with the doors and windows open. Generators produce a significant amount of CO, and operating them in enclosed or partially enclosed spaces can quickly lead to deadly levels of CO poisoning.

My air conditioner is brand new. Does that mean I don’t need to worry about CO?

While a new air conditioner itself won’t produce CO, it can still contribute to negative pressure. The age of the air conditioner is not the primary concern; rather, it is the proper installation, operation, and maintenance of all fuel-burning appliances and the integrity of their venting systems that are most critical.

If my furnace and water heater are electric, am I safe from CO poisoning?

If you do not have any fuel-burning appliances (including gas stoves, fireplaces, or attached garages where vehicles are running), the risk of CO poisoning from appliances is significantly reduced. However, a neighbor’s malfunctioning appliance or other external source of CO could still potentially affect your home, so CO detectors are still a good idea.

What is backdrafting, and how does it relate to air conditioners?

Backdrafting occurs when the exhaust gases from a fuel-burning appliance are drawn back into the home instead of being vented outside. Negative pressure created by an air conditioner can contribute to backdrafting, especially in tightly sealed homes with poorly maintained or improperly vented appliances.

What should I do if my carbon monoxide detector goes off?

Immediately evacuate the premises and call 911 or your local fire department. Do not re-enter the building until it has been inspected and cleared by qualified professionals.

Are there carbon monoxide detectors that connect to my smart home system?

Yes, smart CO detectors are available that can send alerts to your smartphone or other devices if CO is detected. These detectors can also integrate with other smart home devices, such as smart thermostats, to automatically shut down the HVAC system if CO is present.

Can a clogged chimney contribute to CO problems when the air conditioner is running?

Absolutely. A clogged chimney prevents proper venting of exhaust gases from fuel-burning appliances, leading to a buildup of CO. The air conditioner can then circulate this CO throughout the house. Regular chimney sweeps are essential for maintaining safe venting.

How can I test for negative pressure in my home?

A simple test involves closing all doors and windows and turning on your air conditioner. Then, hold a lit incense stick near the draft diverter of your furnace or water heater. If the smoke is drawn down into the draft diverter instead of rising up the chimney, it indicates negative pressure in your home. However, it is recommended to have a professional perform a more thorough assessment with specialized equipment.