For starters, you need to assess what you can burn in your fireplace, since you can’t just toss a handful of corn onto the andirons and expect a toasty blaze. Wood pellets and corn pellets can only be burned in pellet stoves that are specially designed to slowly feed the pellets into the flames. If you already have an airtight woodstove or insert, you have little choice but to burn natural wood, trust the age old rule: the drier, the better. Most firelogs are not recommended for burning in airtight woodstoves or fireplace inserts — unless you leave the doors open, which would significantly decrease the efficiency of your stove. If you have a regular decorative fireplace with no insert, you do have a choice to make: natural wood or firelogs? But which are the greenest?

The uncomfortable truth: old fashioned decorative fireplaces are not green, since they send most of their heat straight up the chimney. The best thing to do with such a fireplace is to add a modern insert, an addition that will increase the fireplace’s heating efficiency from near-zero to the 70-85 percent range. But if that’s not in the cards this winter, here are some tips to help you choose a suitable fuel to burn:

Smoke gets in your eyes Natural wood is considered a carbon neutral fuel, since burning it only releases the amount of CO2 that the tree sequestered in its lifetime. It’s not necessarily the wood that is the problem, it’s the smoke. Burning wood badly (using wet wood or letting a fire smoulder) can release excess methane, a gas that has a greenhouse impact 20 times greater than that of CO2. What’s more, burning wood in an open fireplace releases large amounts of ash in the smoke. The particulate matter in smoke is not healthy and can cause illnesses like bronchitis and aggravate chronic heart and lung diseases. Wood smoke becomes air pollution once it goes up the chimney.

Real vs. fake On the other hand, firelogs can burn relatively cleanly and release less ash than their natural wood counterparts. A study done by the EPA compared emissions from real logs and five brand name artificial logs and found that fake logs had 75 percent less than real wood with 80 percent less particulate matter. They also warm your house more efficiently since they burn longer and hotter.

Sawdust and coffee grounds Firelogs are also made from recycled products such as sawdust or like the Java Log – recycled coffee grounds. The firelogs to avoid are those held together with petroleum wax because of their significantly higher CO2 emissions and for their possible adverse health effects. Good green firelogs should be made with bio-wax and contain no petroleum by products.

Some options:

Make your own

Re-use all that newsprint and make your own logs. The simplest way is to roll up the newspaper tight. The EPA recommends soaking the paper beforehand to remove clay. You can also buy a log roller.