Air Conditioner Maintenance: Tips and Intervals

Do AC Units Emit Deadly Carbon Monoxide

We’ve all heard about the silent killer, carbon monoxide (CO). But have you ever stopped to wonder if your air conditioning unit, which provides you with cool comfort during the scorching summer months, could be a potential source of this deadly gas? Let’s dive deep into this topic and uncover the truth.

Introduction to Carbon Monoxide and its Dangers

Carbon monoxide is a colorless, odorless gas that can be lethal when inhaled in large amounts. It interferes with the oxygen-carrying capacity of the blood, leading to a lack of oxygen reaching the body’s cells and tissues. This can result in symptoms like dizziness, headache, nausea, and even death in severe cases. Given its dangerous nature, it’s essential to know the sources of CO in our homes.

The Basics of How AC Units Work

Before we address the main question, let’s understand how an AC unit functions.

Components of an AC Unit

An air conditioner consists of several parts, including a compressor, condenser, expansion valve, and evaporator coil. These components work in tandem to remove heat from the indoor air and release it outside, thus cooling the room.

The Cooling Process

The process begins with the refrigerant absorbing heat from the indoor air as it evaporates. This vaporized refrigerant then travels to the compressor, where it’s compressed and heated. It then moves to the condenser, releases the heat outside, and becomes a liquid. The liquid refrigerant then goes through the expansion valve, where it’s cooled and turned back into a gas in the evaporator coil, ready to absorb more heat.

Do AC Units Produce Carbon Monoxide?

The Truth Behind the Myth

The straightforward answer is: No, air conditioning units do not produce carbon monoxide. They don’t involve any combustion process, which is the primary source of CO. The misconception might arise because some homes have combined HVAC systems that include heating components, which, if malfunctioning, could produce CO.

Factors Leading to Misconceptions

Many people confuse furnaces, especially gas furnaces, with AC units. Furnaces that burn fuel can produce CO if they’re not functioning correctly. However, it’s crucial to differentiate between the two and understand that AC units, by themselves, do not emit carbon monoxide.

Sources of Carbon Monoxide in Homes

Combustion Appliances

Gas stoves, water heaters, and furnaces are typical sources of CO in homes. If these appliances are not adequately vented or malfunction, they can release carbon monoxide into the living space.

Blocked Vents and Chimneys

Blocked or improperly functioning vents and chimneys can cause CO buildup. It’s essential to ensure they’re clear and working correctly to prevent any potential hazards.

How to Ensure Safety from Carbon Monoxide

Installing CO Detectors

One of the best ways to protect yourself and your family from CO poisoning is by installing carbon monoxide detectors in your home. These devices will alert you if there’s a buildup of the gas, allowing you to take immediate action.

Regular Maintenance and Inspection

Ensure that all your combustion appliances are regularly inspected and maintained. This will not only ensure their efficient operation but also reduce the risk of CO emission.

Proper Ventilation

Always ensure that your home is well-ventilated, especially if you’re using combustion appliances. This will help in dispersing any small amounts of CO that might be released.


While air conditioning units do not emit deadly carbon monoxide, it’s essential to be aware of the actual sources of CO in homes and take necessary precautions. By staying informed and proactive, you can ensure a safe and comfortable living environment for you and your loved ones.


  1. Do window AC units produce carbon monoxide?
    • No, window AC units, like central AC units, do not produce carbon monoxide.
  2. How often should I inspect my combustion appliances for safety?
    • It’s recommended to have them inspected annually by a professional.
  3. Where should I place carbon monoxide detectors in my home?
    • Install them near sleeping areas and on every level of your home for maximum safety.
  4. Can cars produce carbon monoxide?
    • Yes, cars emit carbon monoxide from their exhaust, which is why it’s dangerous to leave a car running in a closed garage.
  5. How can I ensure proper ventilation in my home?
    • Regularly open windows and doors, use exhaust fans in areas like the kitchen and bathroom, and ensure vents and chimneys are clear and functioning correctly.