Spare the Air days: when you can use your fireplace
On a winter Spare the Air alert, burning wood in the Bay Area is prohibited for most households, including in fireplaces and most wood stoves. A small number of homes qualify for an exemption, and gas appliances are unaffected.
What a winter Spare the Air alert actually is
The regional air district issues winter Spare the Air alerts when cold, still air traps wood smoke near the ground. Wood smoke is the largest source of wintertime fine particulate in the Bay Area, which is why the restriction targets burning rather than driving. Alerts are called a day ahead and apply for a full 24 hours, and the winter season generally runs from the start of November through the end of February.
The rule is not advisory. On an alert day it is illegal for most households to burn wood, manufactured logs, pellets or any other solid fuel indoors or out. Check the current season's rules and sign up for alerts with the air district directly, because the details and the enforcement have changed over the years.
Who is exempt
Two exemptions matter to most people. The first is for homes where wood is the only source of heat, which is rare on the Peninsula but does exist in older coastal and hill properties. The second is for households in areas with no natural gas service. If you think you qualify you generally have to register in advance rather than claim it after the fact.
Owning an EPA-certified stove or insert does not by itself exempt you from a winter alert, which surprises a lot of people who upgraded specifically to burn cleaner. It does make every non-alert night dramatically cleaner and cheaper, and it is what the rules are steering households toward.
What you can still use
- Natural gas fireplaces, log sets and inserts
- Gas or electric heating of any kind
- Outdoor cooking on a gas or charcoal grill, which is not indoor heating
This is the practical reason many Bay Area households convert. A gas log set or sealed gas insert gives you a fire on the coldest, stillest nights of the year, which are exactly the nights alerts are called.
If you burn wood, burn it well
On the nights you can burn, how you burn changes how much smoke you make. Use wood that has been split and dried for at least a year, keep the fire hot rather than smouldering overnight, and never damp a fire down to make it last. A smouldering fire produces far more particulate and far more creosote in the flue.
A flue that has not been swept restricts draft, which makes the fire burn cooler and smokier for the same wood. If your fireplace has been hard to light or has been pushing smoke into the room, an annual sweep usually fixes both the smoke and the smell.