Learn How HVAC Systems and Carbon Monoxide Detectors Affect Each Other

Understanding the relationship between the HVAC system and the carbon monoxide (CO) detectors in your Vancouver, WA, home is essential. Although these two systems are separate, they share several important connections. By learning how each impacts the other, you can protect the health and safety of all building residents.

What Carbon Monoxide Is and Why CO Detection Is Important

Carbon monoxide is a natural byproduct of incomplete fuel combustion. Wood-burning fireplaces and stoves, coal, gas, and oil-fired furnaces, and gas-burning water heaters are just a few common CO sources. If you use a propane grill outdoors, the resulting CO isn’t a concern. This gas quickly dissipates in the outdoor air, and people around it are virtually unaffected.

Unfortunately, with fuel-burning appliances installed inside your home, residents are constantly at risk of CO exposure. By law and according to the local building code, all fuel-burning appliances must be properly vented to release CO and other harmful emissions outdoors. However, even the best venting systems can develop problems over time. Exhaust vents can be blocked by frozen precipitation, nests, pests, and even buildups of leaves and twigs. Impact-related damages caused by falling tree branches or other heavy, fast-moving items can also leave exhaust vents with crushed or pinched sections that block the release of CO.

Worse still, CO is both odorless and colorless. Without functional CO alarms installed, no one in your home will know that they’ve been exposed until unpleasant and potentially fatal symptoms develop.

Signs of Carbon Monoxide Exposure

Physical responses to CO vary according to the level of exposure. When indoor concentrations are especially high, this gas can lead to breathing troubles, fainting spells, seizures, and death. When CO concentrations are much lower, people experience the preliminary symptoms of CO poisoning. These include:

  • Headaches
  • Weakness
  • General fatigue
  • Nausea and vomiting
  • Chest pain

Ignoring these early, flu-like symptoms can prove disastrous. As CO concentrations increase or as the body becomes increasingly overwhelmed, carbon monoxide gradually displaces oxygen in red blood cells and may cause permanent physical damage or a total body shutdown.

CO Is Also a Fire Risk

Carbon monoxide also poses a fire risk. It has a high level of flammability and an exceedingly low flash point. Much like natural gas leaks, CO leaks can cause fires and dangerous explosions.

HVAC Systems Can Both Create and Distribute CO

You don’t have to have gas-fired or oil-fired HVAC equipment to face the risk of CO exposure and poisoning. Even when the offending appliances aren’t part of HVAC systems, HVAC systems can still have a hand in distributing exhaust from CO leaks.

Leaky HVAC Air Ducts

If your HVAC air ducts are old, leaky, or unsealed and uninsulated, you have an increased risk of CO exposure. Leaky air ducts often take in dirty, unfiltered air from attics, crawl spaces, and basements. Not only is this air rife with dust and other particulates, but it also has a high likelihood of containing CO given that fuel-burning appliances are often installed in or vented from these locations.

CO Distribution

HVAC systems draw indoor air in, filter it, extract its humidity, and raise or lower its temperature as needed. This air is then distributed throughout homes for climate control. During this process, your HVAC system might draw in CO from a leaky or damaged appliance and move it to other building areas.

HVAC Air Vents and False CO Alarms

By law, your home should have working CO detectors in all common areas and just outside of every bedroom. If any of your CO alarms are installed too close to your air vents, they’ll measure concentrations of CO in distributed, conditioned air rather than detecting CO in the immediate vicinity. False negatives are especially dangerous given that they eliminate early warnings for building residents.

False Positives From CO Alarms

Professionals typically install CO alarms at least nine feet away from fuel-combusting appliances. Although fuel-burning appliances vent their CO outdoors, small amounts of this gas are usually found just around their perimeters. Installing alarms too close can result in constant alerts and increasingly less urgent responses from building residents.

“Combi” Detectors and False Positives Due to Poor Indoor Air Quality

Many modern homes have combination or “combi” smoke alarms and CO detectors. Combi alarms can be triggered by high concentrations of airborne particulates like dust, hair, and dander. If your indoor air quality (IAQ) is low, your combi alarms might go off even when there’s no real threat of fire or CO exposure.

You can avoid false alarms like these by:

  • Regularly changing your HVAC air filter
  • Scheduling annual HVAC maintenance
  • Having your air ducts professionally maintained
  • Installing integrated IAQ accessories

Additionally, having HVAC air ducts insulated and sealed can both improve your IAQ and prevent your ducts from taking in CO-contaminated air from dirty, low-lying areas.

Excess Indoor Humidity and False Positives

Excess indoor humidity can trigger false positives with certain CO detectors. Although condensing furnaces, ACs, and heat pumps offer limited humidity regulation, you may need additional support. Installing a whole-house dehumidifier could be key to maintaining the relative humidity between 30% and 50% that’s recommended by the U.S. Environmental Protection Agency (EPA).

What You Can Do to Prevent CO Exposure and Poisoning

Your HVAC system can lead to CO poisoning both directly and indirectly. The good news is that in addition to maintaining high-functioning venting systems and working CO detectors, there are many things that you can do to prevent carbon monoxide exposure.

Maintain Adequate Ventilation

According to the EPA, indoor air can be two to five times more contaminated than outdoor air, and poor home ventilation is one of several reasons why. With adequate air exchange moving trapped, indoor toxins out and bringing fresh outside air in, minute concentrations of CO can escape before triggering alarms.

Having licensed professionals tighten your home’s envelope rather than doing it alone is also important for avoiding CO problems that are caused by overly airtight buildings. If you over-insulate your home and seal up all natural means of air exchange, you run the risk of creating negative air pressure and causing dangerous back-drafting events. With back-drafting, exhaust gases are pulled down exhaust vents until negative air pressure is corrected.

Professional HVAC Installation

Part of maintaining balanced indoor humidity and avoiding false alarms is making sure that your HVAC equipment is properly sized and installed. Undersized heat pumps and ACs will always struggle to extract excess moisture from the air. When sizing heating and cooling equipment, we use the Manual J Load Calculation for optimum HVAC safety and efficiency.

Professional CO Detector Maintenance and Installation

Although CO detector installation seems like an easy do-it-yourself project, it’s best to leave this job in the hands of seasoned professionals. We’ll make sure that your detectors are sufficiently far away from both HVAC air vents and fuel-burning appliances.

During annual tune-up services for fuel-combusting appliances, have your CO alarms tested and inspected as well. This is the perfect time to replace batteries and make sure that all electrical connections and sensors are in good condition.

We help homeowners in Vancouver, WA stay comfortable and safe with top-notch HVAC installations, maintenance, and repairs. We also provide oil-to-gas conversions, IAQ improvements, and home comfort and efficiency upgrades. For help limiting the risk of CO exposure in your home, contact Revival Heating & Cooling now!