script type=”application/ld+json”> { “@context”: “//schema.org”, “@type”: “WebSite”, “url”: “//rawchimney.com/”, “potentialAction”: { “@type”: “SearchAction”, “target”: “//rawchimney.com/search?q={search_term_string}”, “query-input”: “required name=search_term_string” } } < /script>

Blog

How Does A Wood-Stove Work

Wood-stoves today can complement almost any décor, can be highly efficient and one of the lowest net contributors to green house gasses available.  Are they for everybody?  No, and there are reasons for that, but where they work they are a great alternative.

­What does the word wood-stove bring to mind?  Perhaps the “roaring fire”, the “incredible warmth”, the “glowing dancing, flickering flames”.  Whatever it is, many of us enjoy wood-stoves for varying reasons.  Wood-stove industry has made incredible gains in the past decade or two, and if your wood-stove is over 20 years old, it is likely time to consider replacement.  While you may consider replacing an appliance to save energy costs, many forget about the wood-stove as it appears to be old-technology.  In fact the wood-stove has made perhaps greater gains in efficiency and pollution emissions in the past two decades than any other home appliance.

However, the same can not be said of the fireplace.  An open fireplace is notoriously inefficient, and some of them can actually make your home colder.  The use and idea of a fireplace is actually not in anyway related to efficiency of green house gas emissions.  They can be made better with a fireplace insert, and an insulated chimney liner, but still not as good as the best EPA certified wood-stoves.

Fact is for most people, the best option for flexibility, cost, efficiency and green house gas reductions is the certified wood-stove.

The Chimney

YOUR CHIMNEY IS THE ENGINE FOR YOUR WOOD HEATING SYSTEM

If your chimney is not working properly; neither will your wood stove, fireplace or furnace.  Without a good chimney the rest does not much matter.

WHAT IS A GOOD CHIMNEY?

  • the right chimney for the appliance is is serving;
  • sized correctly for the appliance – most often the same size as the appliance outlet collar;
  • located and positioned properly – generally within the heated space of the home (or if exterior then at least insulated);
  • installed properly – as per manufacturers instructions, Ontario Building Code and CSA B365 – which ever apply for the particular chimney.

A GOOD CHIMNEY WILL

  • allow fires to be lit easily and have a good draft
  • will not fill room or house with smoke when lighting a fire
  • will not spill or puff smoke back into room when door of wood stove is opened
  • will not emit foul stinky odors or a cold draft into the room when not in use

If you are planning to have a wood burning system installed.  The first critical component is the chimney.  Get reliable advice on the type and location of the chimney to be installed.  Most wood heat retailers and chimney sweeps can provide guidance in this area.  For most people it is preferable to have a professional install the chimney versus doing it yourself.  Once installed you MUST have a WETT Inspection – and you will need to find a WETT Certified Chimney Sweep, WETT Certified Technician or WETT Comprehensive Inspector to do this – the SITE BASIC Inspector is not permitted to perform inspections on new installations.

GOOD CHIMNEY PERFORMANCE = GREAT STOVE PERFORMANCE!

  • If there is no fire burning and the door is open, air should flow into the stove – not out.
  • When you light kindling the smoke should flow toward the chimney, not back into your face.
  • Kindling when lit should burn with a bright hot flame very quickly.
  • A properly built kindling fire burns bright and hot very quickly.
  • If operated properly there should never be any smell of smoke in the house.

HOW DOES YOUR CHIMNEY WORK?

If the chimney is the engine, then the fuel it needs to work is heat.  The more heat the better and more it works, however a good chimney really will not need much heat to work properly.  The more heat you put into it the more draft or power the chimney will deliver.

The stove helps the chimney produce more power (draft) and the chimney in producing the draft helps the stove work better.  The two of them in a good system work hand in hand.  A chimney that is interior to the home or one that is insulated is able to product more draft with less heat in is essentially a more efficient producer of energy/power (draft).

Chimneys do need heat to work properly and in doing so they do rob the home from heat.  Most chimneys need around 20% of the wood heat, which means that the stove is unable to send more than 80% into the home.  However, the more efficient the chimney is, the better the system functions and the more heat you have inside the home for each stick of wood burned.  Because the chimney needs the heat, stoves running much over 80% tend to have water vapor condensation inside the chimney, especially on exterior masonry chimneys.  Do not starve your chimney of heat as it does need heat to function properly.

In winter, a well-designed and properly installed chimney will always make draft and upward air flow, even without a fire burning.  When a fire is lit, the kindling ignites and burns easily, draft increases quickly and there is a nice, bright, hot fire immediately without any smoke in the house.

UNDERSTANDING HOUSE SCIENCE

Warm air inside the house wants to rise, and pull in cooler air at the lower points of the home.  This is a naturally occurring air flow in any home and is called stack effect.  The cooler the outside air, the stronger this air flow and pressure differential becomes.  The top of the house has a higher pressure and the basement a low pressure, in the middle of these two zones where the pressure is equal to outdoors is called the neutral pressure plane.  This pressure plane will move up and down in actual location in the home depending upon temperature differentials between inside and outside, the operation of exhaust fans in the home, etc.  If the home is tightly sealed this pressure can build to a greater degree and turning on exhaust fans in a tightly sealed home only exaggerates this further.  If the wood stove is situated in the basement, the lowest pressure point location and this pressure differential becomes high enough, air can be drawn in through the chimney in a reverse direction – sucking smoke and flue gases into the home with it.  In this example, you would need a very good chimney and wood stove to enable overcoming this situation at all times.

COMMON PROBLEMS & AVOIDING THEM

1. Cold hearths and odors: when no fire is burning, cold air and/or odors seep from the stove.

  • The air in a chimney that runs up the outside of the house gets chilled, so the draft in the chimney is less than the stack effect of the house, and the chimney backdrafts, making the hearth cold and causing unpleasant odors
  • Cold backdrafting can also happen if the chimney penetrates the warm part of the building below its highest level, which it will if the hearth is installed at the low side of a cathedral ceiling, or in a single story section of a two-story house
  • Install the chimney inside the building and have it penetrate the warm space at its highest level and it will make draft, even when no fire burns

2. Open door smoke spillage: when you go to reload, smoke rolls out the door.

  • When you open the stove door, a lot of dilution air must flow through the opening to keep the smoke inside; if the exhaust flow is restricted, smoke will roll out into the room
  • Go straight up, if possible; avoid 90 degree turns in the flue pipe and offsets in the chimney

3. Sluggish performance: smokey fire, hard to get a hot fire burning.

  • Large, cold chimneys, like old brick ones, suck up the heat from the exhaust, causing slow draft build up.
  • Size the flue to match the stove and use an insulated chimney to keep exhaust hot and moving quickly; never use an air-cooled chimney

DESIGN GUIDE SUMMARY

1. Put the chimney inside the warm building environment
2. Go straight up, no elbows or offsets
3. Insulation around the flue liner
4. Flue sized to match stove

OUR CANADIAN WINTERS

Follow the design guide carefully or during our cold winters you will be sorry. Good design will pay off.

Wood Stoves The Number One Wood Heating Option Today

The most popular wood heating option today, by far, is the wood stove.  It can be a flexible, economical and efficient option, they can be located almost anywhere there is enough space and where the chimney can be properly routed.

The perfect installation would have a wood stove centrally located on the main floor living area of a home and the flue pipe running straight up through the roof.  This installation often has the maximum degree of comfort, best performance and least amount of maintenance.

The wood stove design is defined as a space heater, intended to heat a space directly, this is unlike a central heat furnace which supplies heat to various parts of the home via duct-work.  With modern homes which conserve energy so well, it is very possible and practical to heat an average-size home with a single wood burning space heater located in the main living area.

A couple of things to keep in mind if you plan to heat with wood.  The first is to locate the stove in an area of the home where the family will spend a lot or most of the time.  Secondly there should ideally be an easy way for heat to flow from this room to other parts of the home.  Often times these two conditions are easily met if thought out in advance.

Selecting the best location for your wood stove is the single most important decision in the entire installation.  Keep in mind that part of the home will be the warmest, and generally is the main floor area near the kitchen, living and dining rooms; and where families spends a lot of their time.  This allows the eating and relaxing areas to be comfortable.  In most homes the basement is not an ideal location for the installation if you would like an effective space heater.  Although the warm air will rise, in many homes it will be a very slow process and may not produce intended or desired results.  When in the basement, you will see that area overheated in an attempt to keep the living area warm enough.  If the basement is unfinished this is an even poorer choice.

Now there are some homes where there are a lot of small rooms and heat does not flow well from one to the other, in these homes it may be difficult to heat with a single space heater.  A large heater will overheat one area, and provide inadequate results in the rest.

It is important to have correct stove sizing, placement and even the number of stove(s).  A large stove will be operating with low smoldering fires to avoid overheating the room, and an undersized stove may be damaged by over-firing in an attempt to get enough heat.

It is also worthwhile to get an efficient stove design, while they may cost more they will save considerable amounts of wood, and if you are buying the wood you may pay for the difference in the first winter.  On average EPA certified stoves are about one-third more efficient than older stoves and sometimes more.  I have seen some modern stoves that actually used only around 25% of the wood used by the stove it replaced!  Now that is an exception and don’t count on that in your home as each situation is different.  Also the new stoves are far less polluting, with average advanced stoves sending around 90 percent less particulate matter and smoke up the chimney than the older stoves.  With a new stove, once the fire is ignited, you will not be able to see any visible smoke from the chimney.   The neighbors will not ever complain about the smell or thick smoke in the air.   Generally speaking the newer stoves provide a far more convenient and pleasurable wood burning experience.  Most of the new stoves also have a glass panel in the door and use air-wash system to keep the door clear. This not only allows you to monitor the fire, but to sit and watch the flicker of flame.  Keep in mind that when you have 90 percent less smoke, then you also have less creosote, therefore the likelihood of a chimney fire is reduced when operated properly, and secondly the flue will need less cleaning. Having said that if you use the stove as a primary heat source, it is still important to have a clean and inspection performed annually and is in fact law under the Ontario Fire Code.  If you did have a fire caused by wood stove, your insurance company could well ask for evidence of the last cleaning and inspection or they could refuse to pay damages.

Should I Buy A Catalyst Stove?

You may get mixed answers on this, and it is true that the catalytic technology is taking a bite out of some stove shops business.  Because some may not sell catalytic stoves, or not have much of an inventory, they may not recommend them.  In fact some may suggest you not buy one at all.  Instead let’s look at the facts.
First let me point out one important fact – the City Of Montreal implemented by-laws that mandated the maximum emission level of an wood-stove used in the city.  No they did not outright say you needed to buy a catalytic stove.  But the level of emission mandated is awful difficult to meet for non-catalytic burners, although there are a few on the market which may meet the level required.

Keep in mind that regardless of what you may have heard or read, catalytic stoves do not produce more creosote than any other wood burning stove when operated properly.

Yes you do need a chimney sweep, but you do with any stove.  You will in fact need your chimney swept and cleaned every 2 to 3 months if you burn daily as your primary heat source.  In fact if you use your stove daily and you do not need to clean for 2 or three years, that IS NOT A GOOD THING!!  That would that your stove is terribly inefficient and is working as hard to heat your chimney as it is to heat  your home, with the cost of firewood not something you want to hear.

Next you will hear that you need to replace the catalyst and it is very expensive.  As far as cost, I can not quote, you would have to ask the stove dealer on actual cost.

However even a regular stove, I can say that if burned properly and run on a daily basis, the baffle system will deteriorate and require replacement, but it should last between 5 to 12 years.

I did ask one local dealer on a common stove and the price for baffle, side rails & flame shield – installed was around $600 plus tax.

On the other hand the catalyst costs around $300 plus tax and you can install yourself, or I can do it for free when sweeping.  The catalyst will often last around 10 years ( in fact some manufacturers provide a 10 year warranty on them ).

But lets get down to the bottom line – which stove extracts the maximum heat into your home and emits the lowest amount of emissions?  This one should be easy for you to answer.

Burn It Hot – The Hardwood Myth

Old stories are hard to get rid of.  This one about burning hot has roots in our past, and is commonly taught in our area.  It causes considerable confusion in our present and no place in our future.  In fact, some stores who sell stoves do not even understand the burn cycle of a wood stove or how to instruct the consumer on usage.

I know my dad, who was born in Quebec in 1897 was a big fan of hard wood.  I know many others in the local area with similar sentiment.  Hardwood was important in the past, homes were less well insulated, stoves were not terrible efficient, and a big chunk of hardwood would burn longer into the night providing a heat source and maybe even hot glowing coals left in the morning.   Well this is the 21st century, and stoves have changed.  Today most  manufacturers recommend a log that is on average around 15 cm in diameter.  Sticks of wood larger than this will actually decrease the efficiency of your wood stove.   Stove technology today, with highly efficient stove, are  designed to have the air turned down to the point that the flames in the box actually extinguish.  The stoves are burning the coals and the heat is released evenly; while the smoke being released is actually burned as part of the combustion in the catalyst.

Sometimes when sweeping I see people who have and do live to the burn it hot scenario.  These often are the same people who do not sweep their chimney on a regular basis.  This means their stove and chimneys often have damage from over firing.  If you burn dry hardwood, please ensure your stove is turned down, protect your stove and your family.

When drying firewood, keep in mint it should be fully dry and sheltered for at least a year.  If you dry it for a year versus only 6 months, the actual heat released from the wood will increase between 15% to as much as 30%!  When burning wood, it is best to mix the hardwood with some softwood, modern wood stoves are designed to and are capable of burning softwood along with the hardwood.  Try to avoid pine as it can have large amount of sticky dirty sap.

Understanding Wood Pellet Quality Certifications

The annual wood pellet production globally is around 30 million tonnes and growing at around 15% annually.   Almost half of all wood pellets sold are used in the industrial sector for power generation, with the remainder used as residential heat and other  commercial/institutional applications.

What is wood pellet quality certification?

Really it is nothing more than a third party verifying and certifying that pellets bearing the label conform to specific quality standards. Within the industrial sector this is not as critical as the buyers and sellers will routinely conduct laboratory tests of samples taken from each pellet shipment.

In the heating sector, this is more important as consumers neither have the means nor the knowledge to perform these types of tests.  This is the main reason the quality certification was developed for the heating sector.

The Wood Pellet Association of Canada (WPAC) manages two pellet quality certification programs: ENplus and CANplus.

The ENplus certification, which began in 2010, accounts for about 80% of pellets sold in the European heating sector. The ENplus program is managed and governed by the European Pellet Council (EPC).

The CANplus certification is very nearly identical to ENplus, the only difference being that CANplus is governed in Canada by WPAC.

Quality certification benefits wood pellet producers and consumers.

Certification protects producers and consumers.  It will ensure that the pellets will perform properly in stoves and boilers.

The rules and procedures for ENplus/CANplus are set out in the program handbooks which can be freely downloaded by going to WPAC’s website at www.pellet.org and clicking on the CANplus tab in the top right corner.

The handbooks set out the specifications for the A1, A2, and B quality classes. The ENplus/CANplus pellet specifications were originally based on European pellet standards, but since 2014, have been based on standards developed by the International Organization for Standardization, namely ISO 17225 Part 2, Graded wood pellets.

Certified pellet producers are required to instruct a listed inspection body to conduct an annual on-site inspection within plus or minus three months of the end of each year following the date of certification. Inspections must include:

  • Taking pellets samples for analysis by a listed testing body;
  • Examining operating equipment;
  • Checking the quality management system, including documentation of operating procedures, quality policy and personnel qualifications;
  • Verifying the origin of raw materials;
  • Checking the greenhouse gas calculation;
  • Reviewing the complaint management system;
  • Verifying the fulfillment of reporting obligations to WPAC;
  • Validating the self-inspections;
  • Verifying production and sales figures; and
  • Ensuring that only approved bag designs are being used.

In Canada, pellet producers have been slow to embrace ENplus/CANplus quality certification. This is mainly because most Canadian wood pellets are exported to the European industrial sector for power generation where quality certification is not used. However, as we continue to grow the Canadian and United States heating sectors, and strive to grow our share of the European heating sector, especially in Italy, it will become essential for Canadian pellet producers to embrace ENplus/CANplus quality certification.