Firelogs Vs. Wood Fires - What's The Right Choice For A Cozy Winter Fire?
    By Kimberly Crandell | December 24th 2008 07:48 AM | 7 comments | Print | E-mail | Track Comments
    About Kimberly

    I'm a mother of three, with an aeronautical engineering degree.  Although it's been a while since I've done any aircraft


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    The winter chill is upon us, and holiday songs put us all in the mood to snuggle by a warm fire with our loved ones... but in this new "environmental age", what should we be using to fuel our roaring fires?  Tradition generates images in our minds of a large stone fireplace, ablaze with a fiery tower of wood - casting heat and light into the room where family and friends gather.  It's warm, it's natural, it traditional... why should we consider anything else?

    But there are other things to be considered, or at least to be aware of, before stocking your fireplace with wood.  There are significant differences in emissions between a wood fire, and a fire fueled by another alternative - "firelogs" manufactured by companies like Duraflame and Pine Mountain.

    cozy christmas fire

    Firelogs came on the scene in the 1960’s when companies were seeking a productive way to dispose of waste sawdust. Manufactured firelogs combine two industrial byproducts, sawdust and petroleum wax, which are mixed and extruded into familiar log like shapes. Manufactured firelogs are generally individually wrapped with paper and require no kindling or starting material.
    Firelogs are easy to light and perform much like a candle with the sawdust particles serving as the wick, and the wax as the fuel. The result is a longer, more consistent burn than cord wood that almost fully consumes the firelog, leaving little ash to clean up after the firelog is finished burning. Their ease of use, physical cleanliness, attractive flame, and good quality fire have made their use in fireplaces very popular - creating an annual national demand of approximately 90 million logs.

    But firelogs aren't known for the one thing that is often sought after when building a fire - producing heat.

    A study in 2006 took a look at several popular firelog brands, and compared their emissions and performance against each other, as well as against a traditional cord wood fire.  Some results were as expected, but some were surprising.  Not all firelogs are created equal.

    Artificial Fire Log Fire

    The study looked at five popular firelog brands:
    Northland,  3 lb. firelog made of wood and wax by Conros Corporation
    Pine Mountain Superlog, 6 lb. firelog made of wood fiber and wax by Conros Corporation
    Easy Time Firelog, 5 lb. firelog made of wood fiber and wax by Duraflame , Inc.
    Xtra Time Firelog, 6 lb. firelog made of wood fiber and wax by Duraflame, Inc.
    Java Log, 5 lb. firelog made of coffee grounds and wax by Robustion Technologies Inc.

    Logs were evaluated by comparing emission factors, emission rates, fuel characterization, remaining residue, burning duration, and maximum temperature.

    Across firelog brands, as well as against results from fires fueled by cord wood, they compared the emissions of:
    • Total Particles (PM)
    • Respirable Particles (PM2.5)
    • Carbon Monoxide (CO)
    • Benzene
    • Formaldehyde
    • 16 individual polycyclic aromatic hydrocarbons (16-PAH)

    As would be expected, the emission rates for all of the pollutants were less for the firelogs than for the cord wood fire.  However, there was some significant variance between the firelog brands themselves.

    Firelog Comparison Table

    As is stated in the report findings:
    It was very interesting to see the variation in the composition and amount of emissions created from these logs. The Emission Rates indicated that the Duraflame Easy Time and Xtra Time products produced about twice as much carbon monoxide as the Conros Northland and Pine Mountain products. It should be noted that the Conros Northland product was about half the size of the Duraflame Easy Time and Xtra Time products (1.4 kg vs. 2.3 kg), however it produced the same level of CO as the other Conros product, Pine Mountain which was the same size as the Duraflame products.
    There were also variances measured in terms of heat generated by the individual firelogs:

    Temperature Generated by Firelogs

    As noted on the bottom of the chart, the heat content (in BTU/lb) was also measured for each of the firelogs.  Although no temperature measurements were made of a comparable core wood fire, an approximate estimation can be made by looking at the energy content of wood used as fuel for a fire.

    For example:
    The energy content of a cord of white oak is approximately 27,000,000 BTU.  (1)
    One cord of white oak weighs approximately 3,863 pounds.  (1)

    Therefore, a corresponding heat content (in BTU/lb) for white oak would be: 6,989.

    They key difference between a firelog fire and a wood fire of course, is size.  Per manufactures' instructions, only one firelog is to be used at a time.  However, when building a wood fire, rarely do you see a single lonely log burning in the fireplace.  In fact there are entire webpages and videos devoted to building the perfect wood fire; and not one will advise you to light a single 5-pound log and walk away.

    Generally, an average wood fire is going to use 20-25 pounds of wood.  With a few calculations, we can see that the total heat content of a 25-pound wood fire is considerably higher than a 5-pound fire log.

    Easy Time, 5-pound firelog:
    5 pounds x 14,420 Btu/pound = 72,100 Btu

    White Oak, 25-pounds of firewood:
    25 pounds x 6,989 Btu/pound = 174,725 Btu

    So when your goal is a blazing fire to fight off the winter chill, chances are a single firelog may not meet your expectations.  However, if your greater concern is reducing emissions - across the board, manufactured firelogs are the way to go.

    In our house, we do a little of both.  When I want the cheery effect of having the glow from a fire in the fireplace, I throw in a firelog.  But my husband is definitely a wood-fire kind of guy (and a legendary wood-splitter too).  So when he builds a fire, he BUILDS a fire... and we tend to enjoy those blazing, crackling, wood fires on cold winter nights and on holidays.  Tonight for example, I'll probably throw in a fire log as I putter around the kitchen and prep things for Christmas brunch, while my husband is otherwise occupied wrapping last minute presents and putting together the truly monstrous mini-jeep that will be delivered to the boys by Santa tomorrow morning.  But tomorrow, after the morning chaos of opening presents has settled... my husband will take the reins and construct a truly huge wood fire for us to enjoy as we play with all of our new toys.

    So depending on what you want out of a warm fire in your fireplace, there definitely some benefits to an old-fashioned wood fire, but also many considerations in favor of the manufactured alternative.  As with all things, it is just best to have the facts to make an informed decision - no matter which it may be.

    Happy Holidays!

    To view the entire firelog comparison study, you can check it out at:


    This article makes me feel warm already!  Just as well, because here it is overcast but not grey, rather the peculiar orangey-pink of sodium reflected from low clouds.
    The swallows have left my cold and sunless land,
    searching for spring and violets,
    nests of love and happiness.
    as the song "Non ti scordar di me" by Ernesto de Curtis (lyrics and translation) goes.

    Which makes me think of chestnuts roasting on an open fire.  'Elf-n-Safety considerations HERE. (see particularly comment #2)
    Robert H. Olley / Quondam Physics Department / University of Reading / England
    JIm Connelly
    I would hope that more people would abandon their open fireplaces and retrofit them with a cleaner burning and more efficient catalytic converter equipped fireplace insert (with a glass front to retain the ambiance of an open flame, if desired.)   

    Burning artificial logs that are essentially a fossil fuel (since most of the BTUs come from petroleum wax) in preference to renewable (and carbon neutral) firewood seems to me to be a bit questionable given the concerns of today.

    Fire logs - are poisonous. Besides formaldehyde and benzene, I wonder what else they emit.
    I cannot be in a room with a firelog burning. I cannot live in areas where wood is allowed to be burned. IF you are human, meaning you can smell and tell if what you are smelling is bad for you - then you would immediately rule out burning wood, firelogs, coal, etc - especially in your home.
    If you don't believe me, study countries where they still use wood or coals to cook with - they die very early age with advanced lung disease and numerous other aliments from the emissions.
    Try Googling pollution inside European churches which burn candles - they are more polluted than the worse cities in Europe, and that is saying a lot.
    Or you could just study the results of lung capacity of people who are around smoke and particulars vs. those who are not.
    The day mothers take control of their home environment - meaning clean air, clean water, quiet areas, safe food, safe building materials for the true health and well-fare of their children will be a great leap for man-kind. As it stands, women mothers go through life with a kind of simpleton touchy feely idiocy blindly buying using any kind of product for their children, some horrible, some good, mostly bad. This article shows us, a well-educated person like Crandell does not necessary have any common sense or way of valuing or even think to value the environment in her immediate vicinity.
    Thank you for article.

    Gerhard Adam
    "If you don't believe me, study countries where they still use wood or coals to cook with - they die very early age with advanced lung disease and numerous other aliments from the emissions."

    I'm sorry, but I don't believe you.  I know, anecdotally, that my mother and grandparents both lived using firewood as the primary means of heat and cooking for the majority of their lives.  While more modern times certainly don't continue the practice, my grandmother died in her eighties, while her husband died in his nineties.  My own mother is in her eighties (with no health problems).  I can also extend this study to include all her brothers and sisters which adds another 12 adults to the example (there were 13 children altogether).  The only one's that died early died from wars, and certainly not wood smoke.

    I am not prepared to consider these statistical anamolies, so therefore I must conclude that your evidence of dying at an early age is also either anecdotal or alarmist. 
    Mundus vult decipi
    Can these be purchased in the UK?

    I use a small compressed java starter for my BBQ - it has a pleasant aroma - and allows me to put the food on the grill right away, since there's no chemicals

    I also only use charwood - not the coaldust/sawdust/glue briquettes soaked in lighter fluid.

    the charwood smoke is pleasant to breath and makes food excellent!

    I have just created a calculator that lets you compare the potential savings of burning firewood, pellets or firelogs vs an alternate heat source. you can check out this widget and even post it on your own site. Take a look: