The following is a guest post by our good friend Miles Dyson of Inspection Connection. Miles is Las Cruces, New Mexico’s foremost expert in home inspection, energy rating, and green certification.
The most important part of “green living” is living! You have an important responsibility this month to make sure your gas combustion appliances are operating safely for the coming winter season. As we close up our Las Cruces, NM homes to crank up the heat, the risk of exposure to carbon monoxide greatly increases.
Carbon monoxide (CO) poisoning at home is responsible for the death of more than 30 New Mexico residents each year. Hundreds of people in the state suffer from diagnosed short- and long-term exposure symptoms and many more are impacted and never know the cause.
The initial symptoms of CO poisoning are similar to the flu, but without the fever. They include: headache, fatigue, shortness of breath, nausea and dizziness.
Carbon monoxide is a colorless, odorless gas that is produced as a byproduct of combustion. All natural gas, propane, kerosene, gasoline and wood heating and cooking appliances installed in our homes produce CO, which is vented to the exterior through a variety of venting strategies. As I conduct inspections and audits in and around the Mesilla Valley, most combustion appliance installations I see meet key requirements for safe operation. Every combustion appliance designed for continuous use must have a source of fresh air to facilitate burning of the fuel and an engineered flue or chimney system to remove CO and other byproducts. A simple change in a fuel burning system’s configuration, either planned or unplanned, can increase the risk of CO exposure.
Leading culprits for combustion appliance CO poisoning at home include space heaters and other devices not intended for use indoors. Barbecue grills, tank-mounted propane heaters and disco and fry pot burners must never be used in any enclosed space.
Unventilated space and wall heaters are still in use in many homes. I grew up with this type of heat – our homes were old and very drafty.
Today’s tighter, weatherized homes amplify the risk when using unventilated space heaters. Manufacturers of “approved” gas-fired space heating appliances include advice that a window should remain open in the area of use. Nothing like an open window in January to help stay cozy!
Properly installed furnace, stove, fireplace and water heating systems can become CO risks due to age, changes in system configuration or to the installed area. We tend to use the utility closet spaces designed to house the furnace and water heater. Fresh-air vent openings must not be restricted in these utility closets.
Stored items should be kept to a minimum to limit the chance of damaging or moving the combustion gas flue connections at the tops of the appliances. The space where the combustion appliances are installed should be fully vented to the exterior of the home and should be treated as an outdoor space.
Access to a gas furnace or water heater closet should remain fully closed and include a seal or weather strip to limit exchange of air to the living space and conditioned air for the home. Any openings to the return or distribution duct system should be sealed. I see this issue in homes of all sizes and price ranges.
I have seen bi-fold or slatted type doors installed to close a utility space. This can allow combustion gasses to enter both the adjacent living space and the return air inlet for distribution to the duct system and all the rooms in the home.
Remodels can fail to provide for combustion appliance safety. Enclosing a garage or patio as a living space where a gas furnace or water heater is installed can put a family at risk. Every remodel that impacts combustion appliances should include oversight by a licensed heating, ventilation and air conditioning (HVAC) contractor.
After years of use, the metal heat exchanger within a furnace may fatigue and crack, allowing combustion gases to mix with warmed air heating your home. Furnaces in service for more than 10 years should be inspected annually by a qualified HVAC technician who will check for cracks in the heat exchanger and determine overall safe operation.
Wood and gas-burning fireplaces and stoves deserve a second look. These units should be serviced every one or two years by a certified chimney sweep or fireplace technician. Dampers must be operable. Firebrick and fireboxes must not be cracked and chimneys and flues must be clean and continuous to the exterior.
Keep gasoline and diesel exhaust out of the house. Make sure the door from the garage to the home stays shut and sealed. Never warm up your car in a closed garage and don’t run generators, chainsaws, mowers or other small gasoline equipment there either. This goes for RVs and campers, too. Work with your qualified RV mechanic to correctly install and maintain generators and appliances. Have your unit checked out, especially after it has been parked for awhile. Along with awareness and inspection of potential CO issues, you should install battery-operated CO alarms or plug-in CO alarms with battery back up. Every home should have a CO alarm in the hallway near the bedrooms in each separate sleeping area. The CO alarms should be certified to the requirements of the most recent UL, IAS or CSA standard for CO alarms. Test your CO alarms routinely (when you also check the smoke alarms) and replace batteries every six months.
The risk of CO exposure is further mitigated when incorporating green and efficient practices for water and space heating. High efficiency/sealed combustion gas water heaters and furnaces include direct ventilation. This means that the combustion sections of these appliances are sealed and do not require a supply of fresh air in the space adjacent to the appliance. The risk of backdrafting or pulling CO and other combustion gases into the living space of the home with this type of system is greatly reduced.
These high-efficiency units also use 25 to 40 percent less fuel than water heaters and furnaces that are not direct vented and are considered the standard for greening your home.
Contact a qualified heating and air conditioning contractor or home inspector/auditor to get a comprehensive review of CO risks in your home.
Check out the following resources to learn more:
- Building Industry Association of Southern New Mexico
- Air Conditioning Contractors of America
- Centers for Disease Control
- Building Performance Institute
- American Society of Home Inspectors
- Residential Energy Services Network
- Inspection Connection LC, Home Energy Rating and
- Residential Green Building Services
Contact Picacho Mountain today at 575-523-2500 for more information on building your energy-efficient, green home in Las Cruces, New Mexico. Custom Estate Homes, Patio Homes, Town Homes, and Neighborhood Retail.
