It has been understood for several hundred years that the brush cleaning of chimneys was necessary. In fact there are records of Master Sweeps dating back to the 17th century where they would employ small boys to climb and scramble up chimneys. The job assigned to these small boys was the cleaning of the inside of the flue with small hand-held brushes. They boys would also use metal scrapers to assist in the removal of any harder tar or creosote deposits which were present. The boys were apprentices and started in the trade as you as seven years old. The Master Sweep would provide room, board and clothing for the apprentice boys, as well as teach the trade. These boys were often sold into the trade by their families, some grew up to be Journeymen or assistants to the Master, the remainder were sent into various other trades to try and learn a new occupation.
The London Society of Master Sweeps had their own set of rules and guidelines, one interestingly enough was that the boys would not work on Sundays, but had to attend Sunday School to study, learn and read the Bible.
The boys however often lived in terribly harsh and cruel conditions, sleeping in cellars on bags of soot and they seldom had a bath. It was a very dangerous and filthy job for the boys to endeavor, as they had none of the modern equipment for safety. There were records of boys choking to death attempting to clean chimneys. Casualties also occurred when the boys became stuck in narrow flues or fell from rotten chimney stacks.
In 1864 Lord Saftesbury brought the “Act for the Regulation of Chimney Sweepers” which established a penalty of £10.00 for offenders, and prohibited the use of Chimney Boys.
The methods for cleaning evolved as well, with some of the tools recognized today being developed in the early 18th century. Mr. Joseph Glass, an engineer from Bristol, invented some of the modern cleaning tools (brush and rods) which are recognized and in use to this day. The design of the brushes and the materials from which they are made has however continued to evolve, and today most sweeps use only a poly brush to do any work. The other common method was the use of brush, ball and rope, which is still common to this day in Scotland.
We have been asked why sweeps wear top hats and tails, and if I have one. The story is that many sweeps got their clothing as cast offs, often from funeral directors. The outfit was practical as it was black in color, and and gave an air of distinction to an otherwise very dirty job.
Not many chimney sweeps carry on the tradition of top hats and tails as their standard attire these days, however there are a few. Some feel that this attire actually demeans the seriousness of the jobs we perform, which are not only sweeping chimneys but include performing repairs, maintenance and code inspections on appliances, flue pipes and chimneys. Some sweeps have bought top hat and tails specifically to wear to weddings, where some sweeps are still called on. **
** Legend has William the Conqueror (King William of England) had his life saved by a sweep, who was able to push the king out of the way of a runaway horse and carriage. The king, as a reward, declared all chimney sweeps to be lucky (permitting them to wear top hats – previously reserved for royalty and the gentry); and also invited the chimney sweep to his daughters wedding. From that point on it grew into the practice inviting a sweep to your wedding. This also over time evolved into the practice of a sweep wearing 13 buttons on their jacket and the legend that a sweep has the ability to cancel any bad luck.
A chimney sweep is a somebody who cleans the ash and soot from chimneys. The chimney in operation uses the pressure difference caused by a hot column of gas to create a draught which will pull air over the hot coals or wood enabling continued combustion. Chimneys may be factory built on masonry in construction. While in operation often times a layer of creosote will build on the inside walls of the chimney, which if left can actually cause a restriction on the flow of flue gases and smoke. This creosote buildup is also combustible and can catch fire causing what is known as a chimney fire and potentially setting the building on fire. Chimney cleaning or sweeping removes the creosote and reduces the chance of a fire in the chimney.
Chimney sweeps are not as common today as in the past, however they still do operate and clean flue pipes, chimneys and venting systems for wood, oil, natural gas, wood and pellet burning appliances as well as dryer vents. With the education available today through associations such as WETT in Canada, there is a much deeper understanding of the dangers of flue deposits and flue gases from combustion.
During the actual clean or sweep, the standard chimney brush may still used, although most have moved to power sweeping tools in Ontario. With power sweeping tools, most sweeps are now able to be performed from the bottom of the chimney, rather than the top. Sweeping from the bottom eliminates the dispersion of dust and debris and is safer for the chimney sweep.
Inspection may be done from the bottom or top, or both if accessible.
Most modern chimney sweeps are professionals, and are usually trained to diagnose and repair hazards along with maintenance such as removal of flammable creosote, firebox and damper repair, and smoke chamber repair.
When heating with wood, often times we are asked which wood produces the most heat. And often times the person asking the question thinks they already know, but the fact is that all wood, regardless of species, has about the same energy content per pound. Where the difference comes is in the density of the wood in each species, for example oak is more dense than ash. The reason the wood favoured traditionally were species like oak and maple were not because they had more btus per pound, but because they were more dense and the same sized block of wood burned longer and provided more heat. Because they were more dense and heavier, this also meant that less wood needed to be cut down, split and piled. However, there are areas of Canada where these species are not available, and wood such as birch or poplar are used instead.
However, regardless of species, by far the most important characteristic of any firewood is its moisture content.
Looking at species, some of the coldest parts of Canada have no dense hardwood to cut or burn. They get along fine, and have for generations on spruce and poplar. It is more important to have wood that is cut to the right size, split properly, piled and dried before use; than it is to have the hardest wood species that grows.
I have and use a moisture meter to test wood, any firewood used for burning should be at 20% moisture or lower. Wood with a higher moisture content will burn, but will be hard to light and will produce excessive smoke and creosote. Furthermore the heat energy will be wasted during the burn and not available to heat your home. Firewood should ideally be between 15 and 20 percent moisture to burn properly, and to reach that level it must be split and stacked in the open for the full summer period. Some old timers in our area have said that you can burn white ash green, and yes you can as ash does have a moisture content lower than many other species, however it is still over 30 percent and much too wet to burn efficiently.
So what is the best species for burning? Realistically if cut, split and dry, the best species is the one you have readily available and is not full of sticky sap.
Table Below Shows Wood Heat In Thousands Of BTU’s Per Cord (128 Cu Ft)
While Other Species Of Wood Exist In Other Parts Of Ontario I Have Listed Common Species In Our Area.
|Large Tooth Aspen||18,200|
If you have a steep steel roof that has a chimney, with or without braces located lower on the roof (more than 3 feet down from the peak). There is a high degree of likelihood that you may have chimney damage each spring. This is going to depend on the winter, where you are located in relation to the lake, etc. It does not happen to all, but I have seen more than a few with damaged chimneys in the spring due to the steel roof and location of the chimney.
When I sweep a chimney or do an inspection I will note this and point it out. The addition of snow splitters, which can change direction of the snow can save your chimney.
Or, you can get a reliable company to monitor your cottage throughout the winter months. Ensure they are aware of the problem and eliminate any built up snow before it becomes a problem.
There are a lot of homeowners that are lucky with the prevailing wind direction, angle of roof and have not had this occur. It really depends on how much snow we get, how deep it piles on roof before sliding off, etc.
Do not procrastinate, because if it builds up it will cause grief.
By Jim Gillam, editor of SNEWS – The Chimney Sweep’s Newsmagazine. This article originally appeared in the March 2001 issue of SNEWS, which is an independent trade journal for chimney professionals.
The U.S. Environmental Protection Agency says certified woodstoves degrade with use, but they still burn cleaner than uncertified stoves.
Jim Gillam says with conscientious woodburning and regular service by a professional chimney sweep, certified woodstoves in the real world nearly match their laboratory emission numbers.
Particulate emissions measured from woodstoves after extended use don’t match the laboratory numbers reported for the same stove models when certified to the U.S. Environmental Protection Agency’s (EPA) Phase II emissions standards, and in most cases are higher, according to an EPA-sponsored study released in December. “But, on average, after about 7 years they still have lower emissions than uncertified conventional stoves,” the EPA report concluded.
Close analysis of the small sample in this study also suggests that conscientious woodburning and regular service of the stove and chimney system by a professional chimney sweep enables a woodstove in active use to burn so cleanly as to nearly achieve the laboratory emissions values.
Due to concerns about air pollution, a maximum level of particulate emissions is enforced for woodstoves. Before any stove model can be sold, manufacturers must submit a sample for testing under controlled conditions in an emissions laboratory.
Air quality regulators are also concerned about the levels of polycyclic organic matter (POM) produced by woodburning appliances.
Primarily due to the high operating temperatures characteristic of woodstoves, some components of woodstoves may become damaged with long-term use. These components include baffles, catalytic combustors, catalytic combustor bypasses, gaskets and seals.
This study attempted to test the suspicion among air quality regulators that air emissions from woodstoves with damaged or worn out parts would be higher than values accepted during the certification process. EPA hired OMNI Environmental Services, Inc. of Beaverton, Oregon, a leading emissions testing laboratory, to examine sixteen EPA Phase 2 certified woodstoves that had been installed in residences prior to autumn 1992. They were monitored “in order to assess the level of long-term degradation and potential increase in PM (particulate matter) and POM (polycyclic organic matter) air emissions of older Phase 2 certified stoves under actual in-home usage.”
The testing took place in November and December of 1998.
The Testing Emissions in the Real World
A total of 43 test runs were performed during three one-week periods. The stoves were located in Klamath Falls and Portland, Oregon.
Though in the same state, the two locations have dissimilar climates. Klamath Falls, situated in an intermountain basin at 4100′ elevation, is relatively arid and cold in the winter with an average heating degree-day (HDD) value of 6600. Portland has a mild maritime climate with rainy winters. Portland’s HDD value is 4109. The intent was to produce results more widely applicable to the nation as a whole than if homes in a single city were selected.
Participants in the study burned locally available cordwood fuel and were reimbursed for its cost. Fuel moisture was measured with a Delmhorst moisture meter, or determined through drying/gravimetric analysis in the laboratory. Wood was div ided into pre-weighed bundles, and any leftover wood was also weighed.
A variety of species was burned. Softwoods and hardwoods including Douglas fir, maple, alder, oak, cherry, birch, and lodgepole pine were burned in the Portland woodstoves. In the Klamath Falls appliances, conifers including lodgepole pine, ponderosa pine, juniper and Douglas fir were consumed.
Wood moisture in this study ranged from 9% to nearly 53% on a wet basis. Wood moisture averaged considerably less in the Klamath Falls group.
A sampling device known as the AWES (Automated Woodstove Emissions Sampler) was attached to the stovepipe of each stove. The AWES was developed by OMNI Laboratories to measure emissions of residential woodburning appliances during normal in-home use. It has previously been used in studies quantifying emissions from woodstoves, masonry heaters, pellet stoves and fireplaces.
In appearance, the AWES was simply an aluminum box that sat near the stove. A stainless steel inlet probe was inserted into the stovepipe 30 centimeters above the flue collar of the stove.
During this study, the AWES was programmed to sample for two minutes every fifteen minutes whenever the temperature of the flue gases exceeded 100°F, indicating that the appliance was in use.
Samples of the flue gases flowed into the AWES through stainless steel tubing. Particulate samples were captured with a heated filter and the oxygen content of the flue gas was measured with an electrochemical cell. Flue gas temperature and room temperatu re were recorded and the flue gas was returned to the woodburning appliance chimney above the point where the sample was withdrawn.
The sixteen used certified woodstoves in this study emitted an average of 11 grams per hour (g/hr) of particu late matter. This is more than double the certification value for those stove models, but substantially lower than the emissions measured from uncertified woodstoves in similar tests.
“Out of the 16 stoves inspected, all showed the effects of use,” the report concluded. “Routine maintenance or minor repairs could have kept all units in good operating condition if they had been done,” the authors (Lawrence H. Fisher, James E. Houck and Paul E. Tiegs of OMNI Environmental Services, Inc., Beaverton, OR and James McGaughey of the Eastern Research Group, Inc., Morrisville, NC) added.
Although this was not specifically tracked in the study, I have personal knowledge of five of these woodstove systems, having serviced them annually as Ash Bros. Chimney Sweep for a number of years.
The maintenance history of the remaining three Klamath Falls stoves, and of the eight Portland stoves, is unknown.
The average emissions rate for the five chimney sweep maintained woodstove systems was 4.8 grams per hour (g/hr). This is very close to the average certification value, 4.2 g/hr, derived in laboratory testing for those stove models. All of these stoves were non-catalytic models. The certification threshold for EPA Phase 2 certified non-catalytic stoves is 7.5 g/hr.
The average emissions rate for the 11 stoves with unknown maintenance histories was 13.8 g/hr, while the average certification value for those stoves was 3.9 g/hr. These stoves included five catalytic models. The certification threshold for Phase 2 catalytic stoves is 4.1 g/hr.
Conscientious Wood Burning
One objective of this study was to document changes in emissions performance of woodstoves over time. An attempt was made to return to woodstoves studied in real-world emissions monitoring conducted in 1989/1990 [see SNEWS July 1990, p. 20] and 1991/1992. This proved to be possible in only two cases. In only one case were the same homeowners (stove operators) involved.
In the only case where emissions from the same stove with the same operators were compared, emissions actually were lower in 1998 testing than they were when the stove was new. In this instance, the same woodstove with the same operators was tracked through three studies over a nine-year period.
The authors of the EPA report said, “The higher emission factor [for this stove] in the 1989/1990 study cannot be readily explained. However, it is probably simply a reflection of the variability often seen in woodstove emissions when different fuels are burned and different burning patterns are used.”
“We’ve learned about the stove,” said Karine Neubert, the owner of the Haughs 171E non-catalytic woodstove that emitted fewer particulates than did any other in this study.
“It burns really well,” Mrs. Neubert continued, “but we were concerned about how it would measure up in this study, because there is a crack in the baffle.”
Mrs. Neubert gave some of the credit for their stove’s low emissions in the tests to their firewood. “We always burn good wood,” she said. “We keep it dry and covered.”
The report documents that the Neuberts burned mostly lodgepole pine during the 1998 study, lodgepole and Douglas fir in the 1991/1992 tests, and juniper during emissions testing in 1989/1990. In each of the three tests, the Neuberts’ wood moisture measured between 13-17%.
The EPA report noted that particulate emissions for stoves in Portland were higher on the average than the stoves in Klamath Falls. “This result is consistent with the average higher fuel moisture content and burn rate characteristics of the Portland portion of the study as compared with the Klamath Falls portion of the study,” the authors said.
“The emission rates for phase 2 stove models reported as part of the NSPS (new source performance standards) certification process do not represent emission levels of the same stove models in homes after extended use,” the authors concluded. “On the average, they still have lower emissions than uncertified conventional stoves.”
The authors were careful to note that “no direct statistical correlation between emissions and wood moisture, burn rate or stove condition could be made due to the number of variables associated with real-world in-home use of woodstoves.”
With this in mind, their conclusion that “the particulate emissions factors of the certified phase 2 stoves evaluated in this study appear to have become higher with use” would appear to be questionable. The disappointingly small subset of two stoves that participated in previous emissions tests and thus are available for comparison doesn’t lend support to this view. One of the two stoves actually had lower emissions numbers in the later tests.
However, observation and photographic evidence definitely confirm that the stoves ‘showed the effects of use.”
The Bottom Line
With the authors’ hint that “routine maintenance or minor repairs could have kept all units in good operating condition” we are led to the most important conclusion available from this small study, although they did not explicitly state it, or perhaps even realize it:
With proper installation and conscientious operation, including use of covered, seasoned wood and regular service by a competent professional chimney sweep, certified woodstoves after years of use burn nearly as cleanly in the real world as they did under laboratory conditions for certification.
Does your stove blow smoke at you when you try to start it? Is this something new that never used to happen? Maybe you need to have your chimney swept and cleaned.
However, if your chimney is outside, maybe it is simply cold air falling down the chimney, which is a natural process. This is somewhat unpleasant, wafts of smoke in the face until you get the air warmed up with a small piece of paper burning to heat the air.
There are a couple of things you may try to see if this helps at all.
- You wood must be dry.
- Covering bottom of firebox create a layer of medium size sticks of wood; around 15 cm in diameter.
- On top of the layer of wood place 3 pieces of fire-starter blocks, space them evenly across the top of the wood layer. 9
- light the three starter blocks and close the door and leave air vent wide open.
- Watch the fire-starter closely – if it needs more air open the door very slightly – just a crack. Observe the ‘candles’ for 1 minute with door closed
- If the fire-starter keeps burning on its own, open the door and fill the stove with wood halfway full. Ensure the fire-starter does not get smothered.
Upon arrival at your home we will evaluate your appliance and venting system. We have 3 separate brush, pole & rod systems as well as a power sweep tool.
I will determine whether or not your chimney will be swept from above or below. It is often easier and safer if it can be done from below.
If, for example your chimney is very high over the roof line and cannot be safely accessed from the roof this type of brush system would be used. You will be told beforehand what will be done, and how it will happen. This is so you will be aware, comfortable and confident with the service that we provide. Our goal is to sweep your chimney system thoroughly and our knowledge and equipment is up to the task.
Lastly, relating to sweeping cost. I have always used a flat rate system. I do occasionally encounter a terribly inefficient systems or some customers using green or wet wood which produces high creosote levels or even a thick glaze in the chimney. Or even customers who only call when their chimney no longer is working properly. These are not the normal cases, but when they do occur there will be an additional cost for the additional work and skill required. There are very rare occasions where I actually am unable to determine the extent of work until getting into the job and in those very rare cases you will be informed after the fact.