Dave Frank/The New York Times After just a few uses last season, we realized that our fireplace was extremely inefficient. So we decided to invest in a cleaner-burning, E.P.A.-certified upgrade. 
The following is the latest in a series exploring the ways Americans are improving the efficiency and reducing the footprint of their homes. Green Inc. readers are encouraged to share their thoughts and experiences in the comments section, or by sending e-mail messages to greeninc@nytimes.com.
The Environmental Protection Agency estimates that there are over 29 million wood-burning fireplaces in American households, and for the most part, they are about as useful as playing this video on your television.
Indeed, beyond their iconic ambiance, traditional masonry fireplaces reach efficiency levels of only 20 to 30 percent when fully ablaze. That means 70 to 80 percent of the heat generated by the fire is being lost up the chimney.
When the flames die down, efficiency can drop below 10 percent.
A wood-burning stove is an improvement, but the agency estimates that 75 percent of the 12 million stoves in use in the United States are woefully inefficient — and polluting.
They don’t have to be.
Federal air-quality regulations have seen to it that wood stoves and fireplace inserts manufactured after 1992 are considerably more efficient and cleaner burning than earlier models.
The problem is that upgrading to an E.P.A.-certified unit — whether you’re in the market for a free-standing stove or a wood-burning insert that slips into your existing firebox — isn’t cheap.
Whatever your budget, though, it’s important to consider the long view. That’s what we did when we decided to have an insert installed at our home in New York’s chilly Hudson Valley (see accompanying video).
As readers of this series know, we took steps last season to minimize efficiency losses by sealing air leaks and adding insulation. Adding a fireplace insert this year made sense when we realized that buying an E.P.A.-certified unit — all of which have efficiency ratings above 75 percent — would qualify us for a 30 percent federal tax credit.
Combine that with the savings we hope to achieve on our use of heating oil this winter, and we might well reap a payback time of less than two years on our unit, which cost us about $3,000 installed.
Of course, efficiency isn’t the only measure of a good stove, as the E.P.A. notes in its new online Burn Wise campaign, launched last month:
Smoke may smell good, but it’s not good for you. Wood smoke can affect everyone, but children under 18, older adults, people with diabetes, heart disease, asthma or other lung diseases are the most vulnerable.
Smoke is made up of a complex mixture of gases and fine particles produced when wood and other organic matter burn. A major health threat from smoke comes from fine particles (also called particle pollution, particulate matter, or PM). These microscopic particles can get into your eyes and respiratory system, where they can cause health problems such as burning eyes, runny nose, and illnesses such as bronchitis.
Older, inefficient stoves and fireplaces can churn out 40 to 60 grams of particulate-laced smoke per hour, while newer E.P.A.-certified stoves and fireplace inserts are designed to emit 2 to 5 grams of smoke per hour — and to reduce the amount of particulate matter released.
Of course, reducing pollution and getting a clean, even burn — even with a modern, cleaner-burning stove or insert — requires proper fuel. As experienced wood burners already know, any old piece of wood just won’t do.
The E.P.A. recommends the following tips:
• Season wood outdoors through the summer for at least six months before burning it. Properly seasoned wood is darker, has cracks in the end grain and sounds hollow when smacked against another piece of wood.
• Wood burns best when the moisture content is less than 20 percent. You can purchase a wood moisture meter to test the moisture content of your wood before you burn it.
• Store wood outdoors, stacked neatly off the ground with the top covered.
• Burn only dry, well-seasoned wood that has been split properly.
• Start fires with newspaper and dry kindling.
• Burn hot fires.
• To maintain proper airflow, regularly remove ashes from your wood-burning appliance into a metal container with a cover and store outdoors.
For some consumers, an even better choice along these lines might be a pellet stove. These units are fueled by dried wood and other biomass waste that has been compressed into pellets, which are automatically fed from a hopper into the combustion area.
And because they pollute so little, no E.P.A. certification is required.
Still, for all the improvements made in wood-burning appliances over the last 20 years, many states and municipalities are introducing wood-burning regulations to curb wintertime pollution.
In the Puget Sound area of Washington State, for example, wholesale burn bans, which restrict indoor and outdoor wood burning, are sometimes imposed when calm, windless weather threatens to permit unhealthy residential wood smoke to settle and linger over the community.
In Albuquerque, stoves and fireplaces that are not E.P.A.-certified are restricted from October to February.
And just this week, the San Francisco area entered its second season of burn bans — imposed on nights the Bay Area Air Quality Management agency deems conditions to be too risky for residents to light up their fireplaces and stoves. Violators will receive one warning, after which they can be fined $400 for further transgressions.
Given this, a worthwhile first step for any homeowner thinking about wood heat this winter would be to check into local regulations first.