We all know safety comes first for HVAC contractors. And while you may not be an expert when it comes to cars, you should know the risks posed by CO poisoning. So, it’s not a bad idea to warn your customers that warming up a car in cold weather — even in the driveway — could lead to CO seeping into their homes.
Winters here at my home office in Cleveland and up at The NEWS’ editorial offices in Troy, Michigan, can be brutally cold. In fact, the winter of 2017-2018 has been a cold one in many places, not just here on the frozen tundra of Northern Ohio/Southern Michigan. But one popular way of fighting the cold may pose some hidden risks for your customers.
Many car manufacturers and aftermarket companies offer a remote start kit option for cars, SUVs, and pickup trucks. The kits seem like a good idea on one level — people don’t want to sit and shiver in a cold car while waiting for it to warm up.
People are aware in a general sense that their cars emit CO, and one would hope that those who live in homes with attached or built-in garages would be wise enough not to warm their vehicles up in the garage (although you never know — wisdom often seems to be in short supply these days). However, people might not be aware that the danger from CO can persist even if they back the vehicle out of the garage and let it warm up in the driveway.
There’s an old saying that homes in the North suck, while homes in the South blow. The meaning in this context is that when a furnace in a home in a cold climate is running, it’s often sucking at least some of the combustion air it needs from outside the home. That means if a vehicle is running in the driveway, the furnace could be sucking in CO from the tailpipe into the house. Maybe not at lethal levels, but there’s evidence that continued exposure to even low levels of CO is hazardous. And CO is still the “silent killer” that it always has always been — the Center for Disease Control reports that about 50,000 people are hospitalized each year, and more than 400 die, due to accidental CO poisoning. A need for education about the risks of CO might be particularly prevalent in the South, where for a greater percentage of the year, homes operate in air conditioning (blowing) mode. Residents of the many Southern states that have dealt with very cold temperatures this winter may be less attuned to the hazards of warming up a vehicle that is parked close to the house.
Way back in 1997, Thomas Greiner, an extension agricultural engineer from Iowa State University, warned that CO levels in automobile exhaust are highest when a cold engine is first started.
Cold engines run rich, and the catalytic converter is not up to its optimal (hot) operating temperature in which it most effectively oxidizes CO to CO2. That means engines are at their most dangerous when they’re cold. So, that is exactly the wrong time to push a start button and let a vehicle warm up when it is in close proximity to a house. In fact, Greiner recommended after starting up a car in an attached garage, the driver immediately back out, shut the garage door, and drive away. This will help prevent concentrations of CO from becoming trapped in the garage and then seeping into the house.
It’s probably not realistic to expect homeowners to stop warming their cars up now that they’ve become used to it. But, there are steps you can take to help protect your comfort-obsessed customers. First, explain the risk to them. Use a puffer stick or smoke stick to show how air can be drawn into their home when their furnace is running, and inform them that even low levels of CO can be dangerous over time. If they still feel they must remotely start their vehicle, advise them to immediately move it as far away from the house as possible, and ideally make sure it is downwind from the house. In addition, recommend they purchase a good low-level CO detector and keep it in the living space — assuming they already have one in the mechanical room.
HVAC contractors and technicians are used to making sure that their customers’ furnaces are operating safely and are not releasing CO into the house. Make sure you keep customers informed about the hazards of CO associated with their vehicles, too.
Publication date: 2/5/2018