From time to time, we receive several inquiries about the same topic. We’ll try to address those topics in a brief, practical way in this ongoing series we call the Go Green Mailbag. This time, we discuss carbon monoxide and combustion safety.

Winter is here, and with it the heating season. If you burn a fuel to heat your home, it is very important to know if your heating system is working correctly- if not, it could be releasing a harmful gas called carbon monoxide (CO). Fortunately, there are some tests to determine whether there is a problem with your heating system, and some ways to resolve those problems to keep you safe –and warm- all winter long. For help with this complicated subject, we turned to CET’s Building Science Specialist Mark Newey.

What is carbon monoxide, and how does my heating system produce it?COsign

Carbon monoxide (often abbreviated “CO”) can be produced in your home if you burn natural gas, propane, oil orother fuels to heat your home. The typical product of burning natural gas (which is made up of carbon and hydrogen) in the oxygen-rich air is carbon dioxide (CO2) and water (H2O). However, if you do not have enough oxygen in the system, CO can be formed. If the CO is properly vented through a flue, it poses no danger to people in your home. However, if it is improperly-vented or otherwise escapes into the living spaces of your home, you could be in real danger.

Why is carbon monoxide dangerous?

Carbon monoxide is poisonous to humans when inhaled. Lower-level CO poisoning often manifests as general poor health, according to Newey. Symptoms may include:

  • headaches
  • light-headedness
  • shortness of breath
  • flu-like symptoms (excluding fever)
  • fatigue

Higher concentrations of CO or prolonged exposure lead to more serious symptoms, including:

  • confusion
  • vomiting
  • loss of coordination
  • loss of consciousness
  • death

Never use a portable generator inside your home.

According to the Centers for Disease Control, “each year, more than 400 Americans die from unintentional CO poisoning not linked to fires, more than 20,000 visit the emergency room, and more than 4,000 are hospitalized.”

CO is colorless, odorless, and tasteless. It provides no warnings that are easily-perceptible by human senses, so it is very easy to not notice that you are in trouble until it’s too late. According to Newey, many CO incidents occur when people try to run gas-powered generators or burners in poorly-ventilated spaces.

What can I do to prevent the buildup of carbon monoxide in my home?

The good news is that you can take steps to prevent carbon monoxide from being a problem in your home. First and foremost, Massachusetts law now requires a CO detector on every floor of a home, including habitable attics and basements. These detectors indicate dangerous levels of carbon monoxide with a loud noise, often similar to a fire alarm, in order to wake anyone sleeping.

Those detectors will alert you to deadly concentrations of CO in your living space. However, it is possible to detect the presence of CO before it reaches such concentrations. Mass Save® is an initiative sponsored by Massachusetts’ gas and electric utilities and energy efficiency service providers, including, The Berkshire Gas Company, Columbia Gas of Massachusetts, Cape Light Compact, Eversource, National Grid, Liberty Utilities and Unitil. As part of a no-cost Mass Save home energy assessment, a Mass Save energy specialist will perform one or more types of combustion safety test. These include:

  • Measuring the CO concentration in the flue pipe and surrounding living space
  • Testing the air flow in a home with all exhaust fans turned on to see if it causes the heating system’s exhaust to vent back into the home
  • Draft testing: measuring pressure in the flue pipe (properly-vented flue pipes have negative pressure, also called a vacuum, which sucks exhaust gases up and out of the home)
  • Spillage testing: creating a puff of smoke near the furnace to see whether any exhaust gases are escaping.

These tests can help to determine whether there is a problem with the heating system, which can then be directly resolved by your heating contractor. This typically involves things like having the system cleaned or adjusting the flue. If you have recommended measures (such as insulation or air sealing) through Mass Save, the cause of a failed combustion safety test will need to be resolved before that work can begin.

So as you begin heating this season, keep your safety in mind. Have a no-cost Mass Save home energy assessment, make sure you have the appropriate number of working carbon monoxide detectors, and if you lose power, remember to run your generator outside. You’ll stay healthy, happy, and warm throughout the winter!

We hope you found this post helpful and informative. For more articles like this, keep an eye on our GoGreen News Blog, and stay tuned for future installments of the Go Green Mailbag!