Fireplace Drafting Problems

Every fireplace season, we get calls from homeowners reporting that they can’t get their wood fireplace burning right, or that smoke spills back out into their house when the fire is going. So let’s take a look at what goes into your fireplace system, and what might be interfering with it:

Draft is the force pulling air from inside your house up through the chimney. Draft is primarily a function of the temperature differential between your fireplace and the outside air, as warm air from inside is drawn up the chimney to meet the cold air outside the chimney stack. The first implication of this is that it will be harder to start a fire on a warm day, since there won’t be a significant temperature difference to kick-start the draw of the chimney. It also means that when you first use your chimney after it’s been idle for awhile, you might have trouble getting the entry to the flue warm enough to get the smoke moving. If this happens, try holding a lit piece of newspaper or kindling up to the flue entrance right by the damper for a minute or two to quickly warm the flue and establish a draft. This can also be helpful on cold, damp days; humid air is heavier than dry air, so your chimney has to work harder to overcome that resistance.

If the flue is warm enough, the outside air cold enough, but you’re still getting smoke spilling back out into the house, the next culprit is likely to be a dirty flue or chimney cap. Creosote deposits will interfere with the airflow through your chimney, slowing it down and kicking smoke back into the house. Having your chimney cleaned and inspected every year or so helps keep this from ever becoming a problem, as well as heading off other potential chimney issues.

Sometimes, even a warm, squeaky-clean flue will refuse to draw properly, depending on how your home and chimney are constructed. A short chimney will oftenflue extenders have problems drawing properly; this can be addressed by adding a flue extender or chimney pot to the top of your flue. This flue extender can help address another cause of smoke spillage, negative pressure. We often have homeowners report that when they use their upstairs fireplace, smoke spills out of the fireplace directly below it. This is because basements, which are partially or completely below grade, are negative pressure zones, which try to pull air in from outside the house (think of it as a very weak vacuum cleaner); positive pressure zones, in upper levels of the home, are where the warm air is trying to escape to the outside. Since the two flues are directly next to each other, extending one flue may be necessary in order to get the smoke away from that negative pressure zone.

A flue extender can also combat the problem of stack effect, which occurs when your chimney termination is lower than a nearby rooftop. Hot air wants to go to the highest point in your house; if this point isn’t your chimney, the smoke will be drawn back into your home as it tries to reach the highest point in your building envelope.

Additionally, adequate replacement air can be a challenge for wood-burning appliances in newer, more energy-efficient homes. In an older, leakier house, cold air is pulled in around windows, doors, outlets, and even through the walls. While you normally want to keep that cold air outside, your wood stove or fireplace needs the replacement air to maintain combustion. In tighter modern houses, an outdoor air kit may be needed. This kit is simply a 4″ diameter duct that runs from the outside directly into your wood appliance, providing enough air to keep the fire from choking out and filling your house with smoke. An alternative to the outdoor air kit is to crack a window or door while the fire is going. For obvious reasons, this isn’t a great long-term solution, but it’s a wonderful diagnostic tool. If you consistently get smoke spillage from your fireplace, try cracking a window during your next fire; if that fixes the problem, it’s quite likely that either negative pressure or insufficient combustion air is your culprit, and an outside air kit may be the best solution.

Not every chimney problem has a simple solution, but there are often steps you can take to make it easier for your chimney to do its job. If your chimney isn’t working as it’s supposed to, it’s important to remember that it’s part of a whole-house system, rather than an isolated appliance, and the root of the problem may lie somewhere else in the house, rather than in the chimney itself.

What Do Efficiency Ratings Mean, Anyway?

Whether you’re comparing wood, gas, or pellet-fuel appliances, you’ll see an efficiency rating listed in the product information. Between uncertain fuel costs and increasingly strict air quality regulations, more and more consumers are looking for the most efficient heaters they can find. But what do those ratings mean? How are they measured?

The bad news is that there isn’t one standard rating system used by manufacturers, nor are they required to tell you which system they’re using. The good news is that by learning a bit about what the ratings mean, you can put manufacturer claims in context and compare apples to apples when buying a stove or fireplace.

What does “efficiency” actually mean?

In the simplest terms, the efficiency rating on an appliance tells you how much of your fuel will become usable heat in your home. A pound of wood, gas, or pellets contains a certain amount of potential energy; some of this energy will be used in starting and sustaining combustion, some of it will go up the chimney (carrying away particulates and other undesirable byproducts of combustion), and the rest will come out into your home as heat.

Wood Heat: EPA vs. Real-World Performance

Wood stoves and inserts are sometimes advertised with two efficiency ratings: EPA and cordwood/real world performance. EPA testing procedures are focused mostly on particulate emissions, and are very highly standardized. These tests use milled lumber (often pine), precisely stacked, with the stove draft set to its lowest (and smokiest) setting; this is also referred to as a “crib wood” test. While this is useful for determining how much air pollution a stove will generate, it has very little to do with how efficiently your stove will convert firewood into usable heat in your home. Many companies choose to do their own testing with cord wood (usually hardwood) and realistic venting setups, in order to give their customers a more accurate idea of stove performance. Unfortunately, there’s no requirement that companies tell you which efficiency rating they’re listing. For environmental impact, focus on the emissions listing (gm/hr of particulates released into the atmosphere) rather than the listed efficiency rating. For real-world efficiency, a good rule of thumb is that 67%-75% is a good range for quality non-catalytic stoves, with catalytic stoves occupying the 75%-83% range.

(Note: just to make this even more confusing, the EPA is currently in the process of revising its compliance and listing standards. While this process is ongoing, look for “cordwood/HHV/actual measured efficiency (CSA)” in your stove literature.)

Gas Heat: Steady-State vs. AFUE/EnerGuide

Gas stoves, inserts, and fireplaces are rated in two different ways. The Steady State efficiency rating, which offers a higher and more impressive number, is taken only once, after the appliance is fully heated up and burning steadily. While this number is technically accurate, it has very little to do with how your stove will perform over the course of its lifetime, and under real-world conditions. We prefer to work with vendors who list the EnerGuide, P4, or AFUE (annual fuel usage estimate) ratings. These efficiency readings reflect performance over the entire burn cycle, from ignition to cool-down, and use realistic venting setups. If you’re looking at efficiency ratings, and seeing numbers in the high 80% range, you’re probably looking at the steady-state efficiency of the fireplace. The more honest EnerGuide, P4, and AFUE rating systems give numbers ranging from around 60%-70%. A 65% efficiency rating is actually quite good, and an 85% rating, although it sounds much better, probably doesn’t reflect an actual increase in real-world efficiency or performance.

To sum up: efficiency ratings can be confusing, and don’t always give a complete picture of how an appliance will perform in your home. However, with a little bit of time and research, you can put those numbers in context when comparing different products, and make a more informed decision about which stove, fireplace, or fireplace insert will be the best fit for you!

 

Common Gas Fireplace Problems: You Probably Don’t Need to Panic

Following up on our recent post about how to address concerns about wood stove performance, here’s a post about your gas stove/insert/fireplace. Since the direct vent gas appliance is a closed system, drawing air from and venting to the outside, there’s much less variation from home to home and appliance to appliance. However, there are a few issues that can crop up with gas units, so here are some common service requests we get, with a couple of troubleshooting steps to try on your own:

My Fireplace Won’t Turn On

At the beginning of each fall, we get a lot of service requests from people trying to turn their gas fireplaces on for the first time in several months, only to find that those fireplaces won’t start. The first, and most obvious question: how are the batteries? Your gas appliance may have batteries in both the remote and the receiver, so it’s important to read your owner’s manual to figure out how many sets of batteries you need to check. It seems obvious, but we’ve gone out to fix several malfunctioning gas appliances, only to discover that the only thing the customer needs is new batteries. It’s worthwhile to keep a battery tester around the house to help you determine whether or not that pack of AAs in the kitchen drawer is still good.

If the batteries in your remote and/or receiver are good, the next step is to make sure the fireplace is getting fuel. If you have a propane tank or natural gas line, are the tank and valves set in the on position? Your gas appliance should have a valve in the firebox, or a key in the wall or floor nearby, and the propane tank will have a knob on the tank outside that opens or closes it. For problems with a natural gas line, contact your city utilities office, and for propane, contact your propane company.

And if you can get your fireplace going, but it keeps turning itself off suddenly, check to see if you’ve left it set in thermostatic mode. We often have that problem in the showroom over the summer, particularly with units we don’t turn on very often; we’ll set the remote to act as a thermostat over the winter, and then in the summer, the fireplace keeps automatically turning itself off!

The Glass on My Fireplace Looks Smudged

Each time you start your gas fireplace, you’ll notice some condensation on the glass. This is a normal part of the startup process, as the water vapor in the air inside the firebox begins to evaporate. This condensation will dissipate within a few minutes, as the firebox heats up and the flames turn yellow. Over time, you can get some buildup on the inside of the glass (residue from that startup condensation), but this is harmless, and easily cleaned off during your annual maintenance call.

My Fireplace Smells Weird

When you start your gas fireplace for the first time after it’s installed, there will be an “off-gassing” period as the residual factory paints finish curing. This, again, is harmless; open the window for your first couple of fires, and the gasses should dissipate fairly quickly. When you then start your fireplace, stove, or insert for the first time each year, you’ll get a slight odor for that first fire or two, as small amounts of dust that have built up over the summer burn off. This shouldn’t last very long; if it lasts more than a couple of hours, or if you start to smell gas or plastic, shut your fireplace off and call your local certified gas appliance expert.

 

Common Wood Stove Problems: You Probably Don’t Need to Panic

Every season, we receive several calls from concerned stove-owners, worried that their stoves are malfunctioning and/or dangerous. The good news is that many of these problems are not actually problems at all, and merely things your stove will do from time to time. Let’s address some of the issues you may encounter in your wood stove or insert, as well as some troubleshooting steps you can take before scheduling a service call:

Discoloration

Some change in the color of your stove can be normal. If you have a stove with porcelain enamel cladding, the enamel may darken as it heats up, then return to its original color as it cools (the bordeaux enamel from Vermont Castings, for example, darkens to a particularly vibrant deep red when the stove is going).

Some wood-burning appliances have a stainless steel firebox, rather than the traditional firebrick or refractory cement. Although this lighter, thinner firebox will transmit heat to your room faster, the lighter constructions means it’s also subject to a certain amount of warping and discoloration (which looks like rust, but doesn’t damage the material of your firebox). During a chimney sweep and inspection, we will inspect any warping or discoloration in the firebox, and assess whether or not it’s severe enough to cause a problem.

Drafting Problems

Sometimes, problems with draft can cause the smoke from your wood stove to come back into the room, rather than going up the flue as it’s supposed to. While a blockage in the flue or the cap may be responsible, there are some steps you can take before scheduling a chimney cleaning.

Image courtesy of woodheat.org

Image courtesy of woodheat.org

The most frequent cause of cool, smoky fires is wet wood, so the very first thing to check is your firewood supply. Firewood that has been properly seasoned (cut, split, stacked to allow free air circulation, and left in the sun and air for at least 9 months) has a moisture content between 15-20%. Dry wood will have cracking and splitting at the ends, as shown in the picture next to this paragraph. Also, if you hit two pieces of firewood against each other, wet wood will make a dull “thud,” whereas dry wood will make a hollow, resonant “thunk.” While this isn’t as scientific or precise as a moisture meter, it will give you a reasonably good idea of how dry your firewood is. Another way to check the quality of your firewood is to look at the smoke coming out of your chimney. At the start of a good fire, the smoke coming out of the chimney will be white; after the fire is fully established, you shouldn’t see very much smoke at all, only a slight distortion from the heat radiating out of the top of the chimney, and a little bit of translucent steam.

Sometimes, the weather outside can be the problem. Damp, heavy air provides more resistance to draft, and it will be harder for your chimney to get a good draw at these times.  And a good draft requires a difference of temperature between the indoor and outdoor air, as the warm air inside your stove is drawn up the flue towards the colder air outside. If the temperature outside is above 55°F, this temperature difference will not be high enough, and it’ll be hard to get a good draft going. You can help your chimney out by pre-heating the flue (holding a burning rolled-up newspaper as near to the flue opening as you can get, for example), but some weather conditions will always interfere with wood stove performance.

Depending on where in your house your stove is installed, some problems with draft may be unavoidable. All homes have a neutral pressure plane, above which air is trying to leave the house, and below which air is trying to get into the house. Many basement fireplaces, unfortunately, are in negative pressure planes, which means they can sometimes experience backdraft from the flue connected to an upstairs appliance. There are steps we can take to reduce this backdraft, like extending one flue so that the smoke isn’t as readily pulled back into the house, but it’s an unfortunate reality that your wood stove may not perform equally well in all parts of your home.

Uncommon Stove Problems: Contact a Professional

While many stove issues are comparatively minor, there are some situations that require the immediate attention of a certified wood service professional. If the wall in front of your chimney, or surrounding the thimble where your stove plugs into the wall, becomes hot to the touch (some warmth is ok, but the wall shouldn’t be too hot to touch), or begins to discolor, stop using your stove immediately, and call your local certified stove technician. If the wall is hot or discolored (turning brown around the thimble, for example), this indicates that pyrolysis is occurring, and often that you have had (or are having) a chimney fire. We inspected just such an installation last year; the flue liner showed evidence of multiple chimney fires, and the wood studs in the wall were beginning to char around the edges. We removed the damaged parts and relined the chimney, but this could easily have started a house fire if left unresolved.

The bottom line is that your wood stove is a complex system, and it’s important to pay attention to how it’s working. If you notice something unusual, don’t panic! There will always be variations in the way each stove performs in different environments, and most of these variations aren’t cause for concern. But as always, if you’re unsure, feel free to call your friendly neighborhood Wooden Sun technicians, and we can discuss your stove problems with you.

Have a safe, warm, and happy fireplace and stove season!

 

 

Company Road Trip: Update

The Hearth, Patio, & Barbecue Expo was great! The HPBA show is an annual opportunity for us to meet with other Hearth & Patio retailers, manufacturers, and distributors to exchange ideas and discuss the current state of the industry. We’ve never taken the entire company before, so this was a brand new (and exciting) experience for most of the staff.

As part of our commitment to ongoing education and training, Wooden Sun employees attended a variety of classes and training sessions. Josh Thornhill, our warehouse manager, is now an NFI-certified gas technician (congratulations, Josh!).We’re waiting on the results for two of our other employees (including your faithful blogger), who took the woodburning certification exam. The certification exams required a full day of class work and a four hour final exam. The whole Wooden Sun team also attended a variety of courses on sales, job site safety, customer service and maintenance and  troubleshooting procedures for wood and gas products.

HPBA trade show

HPBExpo show floor. Photo courtesty of HPBExpo on Facebook

The trade show portion of the week was, of course, amazing. We caught up with our vendors and distributors (or, in some cases, met them in person for the first time!), got some refreshers on the products we sell, and enjoyed a sneak peek of upcoming product releases. We found some new-to-us vendors and products to explore, for both our indoor and outdoor categories. Several of our current distributors are releasing new products and product lines this summer or fall; watch this space for ongoing updates about exciting new products you can find in our store.

HPBA outdoor burn

The BBQ Dragon in action. Photo courtesy of HPBExpo.com

 

Even in the chilly weather, the outdoor burn area was going strong. Grills, smokers, pizza ovens — everything was fired up and producing amazing food (it was also nice to be able to stop at a firepit every few feet to take off the chill). As hearth professionals we were, of course, obligated to sample several different vendors’ offerings, to see which products we might be interested in bringing to our outdoor kitchen and patio line.

All work and no play make for a dull road trip.  Fortunate enough to arrive and leave in the good weather that bookended the storm that had I-40 snarled for 32 miles, we all had a great time in a snowy Nashville. The next time you are in Nashville, we would heartily recommend Morton’s Steak House, especially if you can get a high quality supplier like Olympia Chimney to take you out for dinner! Some of us also took a turn as rodeo stars on the mechanical bull at the Tequila Cowboy, bathed in the Nashville sound at Tootsie’s World Famous Orchid Bars (three floors, each with its own band), or tried to break into the music scene at a karaoke bar, which will remain unnamed in case they have video of the performances.

From stoves and fireplace accessories to grills and patio furniture, there was something for everybody at the HPB Expo, and we enjoyed our time there. We went to Nashville filled with questions and excitement, and came back filled with new information, freshly-polished skills, and lots of great products and ideas for the future!

 

 

 

Catalytic vs Non-Catalytic Stoves: Which One’s Right for You?

So you’ve looked at your options, and are trying to decide on a wood stove. One important choice to make is whether to purchase a catalytic or non-catalytic stove. Which one is the best option for you? Each comes with advantages and disadvantages; there’s no “best” stove, only the best option for you and your home.

Whether you chose catalytic or non-catalytic, Wooden Sun wants you to make an informed choice. Catalytic stoves sometimes get a bad rap, but much of this is based on a previous generation of stoves. Early catalytic stoves were non-catalytic stoves which had been quickly adapted to meet EPA standards; the catalysts were often difficult to get to and hard to maintain, and the stoves simply weren’t as efficient as they could have been. Since then, manufacturers have vastly improved the design of catalytic stoves, and the result is a better, easier to maintain stove.

Here are the facts we have gathered together to help you make an informed choice between catalytic and non-catalytic.

Advantages of a Catalyst

If you’re looking for maximum efficiency and the cleanest burn, a catalytic stove is hard to beat. Just like the catalytic converter in your car, the catalytic combustor in a wood stove traps the smoke and other byproducts of combustion, and has a chemical coating (generally platinum and/or palladium) which interacts with the smoke and ignites it at around 500 degrees, rather than the 1100 degrees normally required. This increases the efficiency of your wood stove 5-10%, especially at low temperatures, and reduces emissions by 3-5 gm/hour. With this increased efficiency, and the ability to burn the fire very low without risk of it smoldering and producing creosote, catalytic stoves can achieve very long burn times — up to 40 hours!

Disadvantages of a Catalyst

There are a few drawbacks to a catalytic stove. The first is that the catalyst is another part that can break down, and it will eventually wear out and need to be replaced. The catalyst can also be ruined by the use of treated lumber, coal, colored or glossy paper, or other non-pure wood and fire starter sources (much as you wouldn’t put lower-grade gasoline in a high-end car). While unseasoned firewood won’t permanently damage your combustor, it will crud it up (again, like non-premium oil or gasoline in a high-end car), reducing its effectiveness. And there is an extra step in the combustion process — opening and closing the bypass damper at the correct times. A final potential drawback of a catalytic stove comes only if you have a particularly short chimney. A shorter chimney may not have the sufficiently strong draft a catalytic stove requires to function at lower temperatures, and the stove won’t be able to achieve its maximum burn time.

Advantages of a Non-catalytic Stove

So you’re concerned that a catalytic stove might require more attention than you want to give your wood stove. In short, a non-catalytic stove is simpler to operate. It doesn’t require the extra step of engaging and disengaging the bypass damper (although we still recommend monitoring the temperature to make sure you aren’t over-firing and damaging your stove). With no catalyst to damage and replace, green wood and the combustor killers mentioned above aren’t as serious a problem, although we still recommend burning only well-seasoned wood and approved fire starters at all times, and never burning trash or treated lumber. Green wood just stinks!

Non-catalytic stoves operate at their most efficient and burn the most cleanly at a moderately hot temperature. This can be an advantage in leaky old farm houses or huge spaces that need a maximum BTU output to maintain a warm environment.

Disadvantages of a Non-catalytic Stove

Although it’s easier to operate, a non-catalytic stove can’t achieve the highest levels of efficiency and the lowest levels of emissions, as compared to a catalytic. Moreover, a non-catalytic stove won’t burn as cleanly at low temperatures. And since it can’t manage the very low burn rates of a catalytic stove, a non-catalytic stove won’t be able to be able to achieve the very long burn times of its best catalytic cousins.

A Tale of Three Stoves

Blaze King Princess

The Blaze King Princess catalytic stove is among the most efficient wood stoves in the world, at 88% efficiency with only 2.42 gm/hour of emissions. On high heat, the Princess will burn for up to 10 hours; on its lowest heat setting, the stove will burn for as long as 30 hours!

 

Pacific Energy Summit

This is the Pacific Energy Summit, an exclusively non-catalytic stove. It’s 80.5% efficient, with 3.9 gm/hour of emissions, and a burn time of up to 14 hours. Simple to operate, this stove is both tough and reliable!

Vermont Castings Encore

The Vermont Castings Encore Flexburn (along with its big brother the Defiant) is unique  in that it can function as a catalytic or non-catalytic stove. Its readily-accessible combustor chamber makes it easy to examine, maintain, and replace the combustor. If you don’t engage the catalyst, this stove is 78% efficient. In catalytic mode, the efficiency jumps to 86%, with only 1.2 gm/hour of emissions.