As heatwaves across British Columbia become more frequent and intense, many households are turning to portable, single-pipe exhaust air conditioning (AC) units to keep cool and comfortable. These window-vented AC systems offer an affordable way to keep individuals, families, and pets from overheating.
However, when portable AC systems are combined with natural draft type appliances, (which can include natural draft water heater, furnace, or fireplace among others) they can create unexpectedly dangerous situations.
A Delicate Balance: How Fuel-Burning Appliances Work
Natural draft gas furnaces, water heaters, fireplaces, and other fuel-burning appliances rely on a careful balance of incoming fresh air for combustion, and proper venting to safely remove by-products like carbon monoxide (CO) from your home. When that balance is disturbed, it can trigger a chain reaction that compromises indoor air quality by drawing CO back into the home.
Natural Draft Appliances and AC Units: A Dangerous Combination
Single-pipe AC units rely on pulling air from inside your home in order to vent hot air outside. This depressurization effect can unintentionally disrupt how fuel-burning appliances vent their exhaust. Instead of being safely released outside, combustion gases like CO may be drawn back into the living space and can build up to dangerous levels, causing CO poisoning or even death.
A Silent Killer: CO Poisoning is Nearly Undetectable
CO is an odourless, tasteless, invisible gas that is produced by burning fuels such as propane, natural gas, oil, wood, charcoal, alcohol, kerosene, or gasoline — all of which are commonly used in homes and businesses. CO interferes with the body’s ability to absorb oxygen, which can lead to serious illness, severe side effects, or death.
Safety First: How to Protect Your Household
To minimize the risks associated with depressurization, here are a few proactive steps every homeowner should consider:
- Install carbon monoxide detectors near fuel-burning appliances and throughout your home. Early detection can save lives.
- Schedule routine maintenance with a licensed contractor to help keep fuel-burning appliances functioning correctly and venting safely.
- Consult a licensed professional before adding any appliance that affects airflow. A contractor can assess your home’s pressure balance and adjust appliance exhaust systems if needed.
Portable AC units can make a big difference in summer comfort, but they shouldn’t compromise your home's safety. With proper planning and the right professional support and maintenance, you can stay cool while staying safe.
