Natural Gas vs. Wood Burning Fireplaces: Pros and Cons
One of the nicest places to be during the winter is in front of a fireplace. Looking into the crackling flames is an age-old human ritual that comforts and soothes children and adults alike. But ask homeowners whether they prefer natural gas or wood burning fireplaces and you’ll soon find a wide gulf arrayed along the divided ideas of look-and-feel, cost, maintenance, convenience, and environmental responsibility.
So, we’ll have a quick, clear look at this burning issue and compare the pros and cons to discover what the benefits are of both. But first, let’s have a quick look at two types of types of fireplaces.
The typical traditional home fireplace is a single-piece brick hearth with an attached brick chimney. The fireplace consists of a small trap door that opens onto an ash pan (to collect fine ash), a wrought-iron grate to hold kindling and logs. Above, mortared into the throat of the chimney is steel damper that can be adjusted by opening or closing to control the amount of air drawn into the fire and exhausted through the chimney. Known as a “throat damper”, they can be closed to seal off the chimney when the fireplace is not in use.
Wood stoves and inserts (which slide into an existing brick hearth) or zero-clearance fireplaces have been around for centuries and experienced innumerable improvements and modifications, most notably the Franklin stove built first by Benjamin Franklin in 1741. As far as heating goes, these fireplaces transfer heat far more faster than brick fireplace. Brick fireplaces don’t heat very efficiently (in fact, most of their heat is sent up the chimney). However to some extent they do act as heat-sinks, meaning they are big piles of brick mass that absorb heat and slowly release heat energy over time. So, while you can heat your home fairly quickly with a wood stove or insert, they lack the themral mass to store heat. And while brick fireplaces don’t heat up very fast, they will retain heat much longer.
Which factor more important to you depends on how you use your fireplace: for heat or as an ornament?
While these two types of fireplaces can burn either natural gas or wood, each fuel has its own pros and cons.
Wood burning fireplaces offer the dancing yellow flames and orange hot coals that give a room a cozy, warm look and feel. The crackling sounds, occaisonal firework-like sparks, and the smell of the burning wood such as fir really add a nostalgic (if not primal) ambiance to a room. And if the fire place is big enough and the right wood is being used, you can actually cook on it with the right cookware.
First of all, you need wood. Now, folks living out in the country can just go outside and they are surrounded by this sustainable fuel. But if you live in the suburbs, your neighbors will probably sue you for singing lumberjack songs as you randomly cut down trees in the neighborhood. So you will need to buy firewood —either at the grocery store or in bulk from someone who sells it.
It is important to remember one obvous fact: wet (or green) wood does not burn well. In order to burn with the most heat and give off the least amount of creosote (see below), the wood must be allowed to season (or dry out). Softwoods should season for over a year, longer for hardwoods. Softwoods and hard woods have different burn properties. Nicely seasoned softwoods (fir or pine) are easy to start. If allowed to burn hot and fast, they will produce very little creosote. Hardwoods, like hickory, pican, and oak (yes, all nut trees) are heavy and dense and are difficult to start burning. But when they catch, they burn low and long.
Wood burning fireplaces also need to be cleaned after the fire is out and the fireplace cools down. The fine ash needs to be swept up so that any sudden puffs of air coming down the chimney don’t blow it out into the room. Plus, fire code standards mandate that chimneys shoud be inspected once a year by a professional chimney sweep in order to prevent the build up of creosote which can cause disasterous chimney fires.
Chimney fires result from layers of creosote building up in the chimney. Creosote is a natural by-product of burning wood formed by carbon compounds and resins in the wood and water vapor. It is a tar-like bad-smelling goo that liquifies when heated and trickles down the sides of the chimney. It is also highly flammable fuel that can burn at about 2000°F. Typically what happens is that fires made with wet wood or little air flow will produce exhaust or “flue gases” that will be cool. Water vapor will condense out and combine with the soot and smoke particulates to form creosote. Over time, the deposit builds up and if it is not cleaned the creosote will dribble down the chimmney until it bursts into a serious 2000°F fire. Heat like that can destroy masonry, melt chimney liners, and quickly engulf the whole roof. This is why chimmney’s need to be inspected and kept cleaned.
Meanwhile, natural gas fireplaces are based on newer heat-efficient technology. They offer many obvious maintanence and installation advantages over wood fireplaces. First of all, there’s no mess from gathering logs, cutting logs, and storing logs to season. There’s no mess from ash, coal-raking, soot, or creosote issues to clean up after. There’s also no mess involved with gathering kindling and building a fire, you just push a button and POOF —flame. You can also install the natural gas fireplace almost anywhere in your house. Because natural gas fireplaces are designed to burn the gas efficiently, the flue gasses are cool enough to be vented through PVC pipe run through the walls. In short, no mess and push-button ease. Total convenience. They radiate heat nicely and some contain fans to circulate the heat efficiently. Plus, natural gas is a cheap fuel —especially since it just through a pipe into your home. It is one less thing to worry about especially if the wood fireplace option mean syou need to buy and haul your own wood. Plus, if there’s a power failure, most can be lit up manually. Of course, that assumes the power failure doesn’t effect the natural gas pumping stations…which happened in Texas on the night of Feb. 2, 2010.
Sifting the Ashes
Now for some folks, convenience is vital and that’s all well and good. On the other hand, there’s something about utterly soul-less about blue and yellow flame shooting up around a bunch of ceramic logs that don’t change or burn away. Watching a dvd of fireplace somehow seems more rewarding because fire-gazing is a very primal human passtime. The clincher for many, though, is that even though they may enjoy all the work and manly woodsman expertise about selecting firewood, the dirty truth is that wood burning fireplaces emit 28 lbs of particulate emmissions per MMBtus of heat output (soot and ash) as opposed to natural gas which produces up to 99% less (about .28 lbs/MMBtu). This means that natural gas fireplaces pose less of a risk of in-home air pollution or smoking out one’s neighbors as well. Wood burning fireplaces might be cozy and soothing (which we all need at some time in the 21st century) and seem a cheap way to heat, but in the end when you look at them terms of expense and efficiency, they are becoming a luxury few can afford to depend on.