This article is based on our experience of replacing an open fireplace with a Stanley Erin stove in a 4-bedroom single-level detached house, how the various coal products compare (plus a few to avoid) and how I light a smokeless fire.
Besides improving our house’s insulation, one of the best investments we’ve made to reducing our heating costs is replacing our living room’s open fire with a stove. The former fireplace had a back boiler and the replacement is a Stanley Erin free standing stove, also with a back boiler. For the first few days after the stove was fitted where it could not be lit due to the wet cement, the living room was noticeably warmer and the floor draught disappeared. In the evening, it felt as if we had a fire lit earlier in the day, but in actual fact the room’s air was no longer being sucked up the chimney.
Losing the open fireplace
The main concerns we had in the beginning were that the stove would not look as nice as the open fire and that the free standing stove would take up space in the living room, however, once we started using the stove, neither concern ever bothered us at all, apart from a short period where we tried burning regular coal which kept dirtying the glass. If the open view is a concern, it’s worth thinking – Is it worth forking out €1000+ a year in additional heating costs just so there is no glass in front of the fire? There are also many stoves with a large glass door giving as clear view of the fire as with an open fire. For the space usage, our stove comes out just a little past where the old mantle was and the former space couldn’t have served any other use anyway other than for a fireguard, which is no longer required.
Experience of running an open fire
When we had the open fire, we burnt roughly a bucket (approx. 8kg) of smokeless or regular coal an evening. It had no problem warming the hot water tank, but could only warm the radiators lukewarm, approx. 35C and no more than approx. 45C with the firebox full and a large blazing fire. Once the fire was up, the living room was quite cosy, but by the following morning it was as if no fire was ever lit. Even if a blazing fire, there was always a cold draught on the floor which was noticeable when not wearing footwear, especially on a cold or windy day. Due to the fire’s inability to properly heat the radiators, we ran the oil for 6 to 8 hours a day and went through over 2000 litres of oil a year with our old boiler. I estimate we would still go through about 1500 litres with our new condensing boiler had we replaced the boiler before getting in the stove.
How the stove changed the way we heat our house
With the stove, we now generally burn between a bucket and a bucket and a half (approx. 8 to 12kg) of smokeless (Ecoglo) coal a day, sometimes mixed along with a few logs on very cold evenings. As for the heat, the stove does not radiate as much heat outwards, but it sure warms the air in the room far more than the open fire ever did and we have to keep at least one door open. While the stove could warm the hot water tank, we had the plumber configure the fire such that the stove warms the upper part of the tank and the oil heats the whole tank. With zone valves on the radiators, we have the radiators cut off from the oil and very rarely heat them with the oil (few days a year at most.) On very cold days, we just burn more coal. With the stove running the radiators, I estimate we go through about 500 litres of oil a year with our condensing oil boiler, at least that’s all we ordered each year over the past two years. Over the winter, the temperature usually reaches 23C in the living room and 20C in the bedrooms.
With a full bucket of Ecoglo coal, approx. 8 pieces of kindle and a firelighter, the following process takes place:
- For the first 10 to 20 minutes after lighting the firelighter, the coals gradually light up. We leave the top damper half-open the entire time and thermostat damper at #2 (of 4).
- By about 30 minutes of lighting, the top of the stove gets too hot to touch and the flames die down as the stove’s boiler causes the thermostat damper to close itself.
- After about 45 minutes of lighting, the thermostat for the radiators cuts in, which causes the stove’s boiler to cool down again. This results in its thermostat damper opening and the fire starts growing in size until it becomes a good blaze across the coals.
- 15 minutes later, the radiators get warm, usually 40C to 45C going by my IR Thermometer. If it’s a very cold evening, we now turn the thermostat damper up to 2.5 or 3.
- By roughly 90 minutes of lighting, the stove is fully warmed up and the coals are all glowing red with the dancing flames, giving a nice pleasant appearance. The living room at this point is cosy and warm. The radiators’ temperature varies depending on how much we open the thermostat damper. Based on readings with my IR thermometer and using Ecoglo, the setting numbers on our Stanley Erin results in the following typical temperatures – 2 : 50-55C, 2.5: 55-60C, 3: 60-65C, 4: 70-75C. For comparison, the oil heats the radiators to roughly 65C.
- After about 3 hours of lighting with the thermostat damper setting on 2.5, about half the coal has burned away and we usually add either a half a bucket of coal or a few logs at this point. As the stove and radiators are already hot, this additional fuel burns much slower and will usually keep the fire going for another 5 hours and then at a reduced rate with the radiators lukewarm for a few more hours.
Despite having the oil cut-off from the radiators, the house remains reasonably warm the following morning, usually dropping to between 18C and 19C from about 20C-21C the night before. The living room itself stays a little warmer, usually 20C until the afternoon. Before we got the stove the living room was the coldest room in the house and we had to run an electric heater if we didn’t light a fire.
Stove maintenance is much the same as with an open fireplace – we usually empty the ashes every day or two and then scrape the soot off the inside surface using the coal shovel before lighting. Every month, I lift the lid off and unscrew the top to scrape the soot off the upper sections using a paint scrapper. This process takes about 30 minutes. We then use an ash vac to remove the scapped the ash and scrapped off suit, including from the chmney pipe out the back.
As for cleaning the front glass, we generally use ordinary window cleaner. If the staining is bad, we dab a wet cloth in ashes and rub this on the glass. Another method that works well is by burning a hot coal or wood fire, which usually results in the soot being easy to wipe off the next day.
Our experience with different types of coal
When we first got the stove in, we decided to try most of the varieties of coal we could get hold of, trying each type on their own for at least a week. As we don’t live in a smoke-controlled zone, we started with Polish premium coals which were the most popular coal people burnt around here and settled on “Doubles” for a few months. After a few full stove cleanings and seeing the pile of soot collecting each time in the pipe behind the stove, we decided to try the various smokeless varieties of coal as well as mixes of coal and wood. The reviews of the two Polish premium types below are based on two years ago before we went decided to only burn smokeless coal. Ecoglo, Ecobright, Anthracite and Union Nuggets are all smokeless coals.
The prices below are based on 2010 for Polish coals and at this time of writing (February ’12) for smokeless coals.
Polish Premium – This coal completely varies in size with pieces varying from the size of size of peas to chunky mug-size pieces weighing half a kilo. It is very easy to light even without any kindle. The coal is best lit from the top to reduce the amount of smoke it produces. After about 20 minutes, it is a bright hot blaze. Due to the heat, it has the radiators hot (approx. 50C) roughly 60 minutes after lighting and a bucket of coal lasts about 3 hours. Adding coal results in the front glass getting dirty, even with the top damper fully open. This coal was €14.50/40kg bag when we last purchased it in 2010.
Polish Doubles – This coal is about the size of tennis balls and is very easy to light just like with the Polish Premium. While much easier to shovel and cheaper than the Premium, the coal produces a lot more smoke from our experience and is also very difficult to keep the glass clean. Adding this coal to an already lit fire will result in the glass going completely black and the only way to at least partially clear it is by turning the thermostat damper up to max (setting 4) for 5 to 10 minutes. This coal also puts the most soot on the upper section boiler parts, requiring weekly full cleanings for the radiators to fully heat up. This coal was €13/40kg bag when we last purchased it in 2010.
Ecoglo (See update below) – Unlike the Polish coal varieties, this coal is made up of the same size pieces, ovoids about the size of tennis balls. Like Polish doubles, this coal is easy to shovel out of the bunker, although not as easy to shovel with the small fireside shovel. This coal needs kindling to light, as it generally will not light with a firelighter on its own. 8 pieces of kindling usually gets this coal to small blaze after about 20 minutes and the whole bucket of coal is fully ablaze roughly 45 minutes after lighting.
The flames are not as bright as with the Polish coal and gradually thin down over the next 45 minutes, at which point the coal is glowing red with light flames dancing about. The flames completely disappear about 2 hours after lighting. To keep the glass clear, we need to keep the top damper halfway open and the glass generally remains clear even when adding further coal. The first bucket of coal will last us about 4 hours, so generally we add coal after about the 3rd hour to keep the radiators hot. This coal leaves a thin layer of soot on the upper inside surfaces, so we usually fully clean the upper section every 4 to 6 weeks depending on the amount of coal we burn. This coal is €17/40kg bag delivered here and is the main coal we burn.
Ecobright – Like Ecoglo, this coal is made of same size pieces, but about the size of small eggs. It is also easier to shovel even with the small fireside shovel. This coal needs plenty of kindling to light and is practically impossible to light using only firelighters. 8 pieces of kindling brings this coal to a small blaze after about 40 minutes and a whole bucket of coal takes about 60 minutes to fully light. Due to the slower lighting period, this coal takes about 90 minutes to warm the radiators and about 2 hours from lighting to get them hot. This coal is very clean burning, giving off very little to no smoke even when adding more coal.
This coal does not burn as hot as Ecoglo and can easily left to burn overnight. Once fully lit, it gives of bluish-yellow flames much like an open gas fire. The coal glows much brighter than Ecoglo, much like the Polish coal after the flames have died down. It also leaves very little soot. This would be our next preferred coal after Ecoglo and is by far the cleanest to burn after Anthracite, leaving little to no soot stuck to inside surfaces. I reckon that if we exclusively burnt this coal, we would only need to clean the upper section once to twice a year. Besides giving few flames, our local coal delivery service does not stock this coal, making it less convenient for us than other varieties of coal. This coal is €16.50/40kg bag from our nearest supplier, FDR tyres near Donegal.
Union Nuggets – This coal consists of hexagonal shaped pieces about the size of tea cups. Like the Polish Premium’s chunky pieces, this coal is cumbersome to handle and is best loaded using tongs. This coal is quite easy to light, although kindling does help it light up quicker. It reaches a blaze state in about 20 minutes and has the radiators lukewarm in roughly an hour after lighting. This coal continuously burns with flames until it has mostly burnt out. Like Ecoglo, it gives off only a small amount of smoke and the glass generally remains clear as long as the top damper is open half-way.
Like the Polish coal, this coal burns with a good bright blaze at this point, but despite the impressive looking blaze, it does not burn as hot, leaving the radiators roughly 10C cooler than Ecoglo for the same thermostat damper setting. The first bucket of coal will fully burn out in about 3 hours, so we usually need to add coal after about 2 hours of lighting and add further coal 3 to 4 hours later on. We need to 1.5 buckets of Union Nuggets (approx. 12kg) for the equivalent amount of heating as a single bucket of Ecoglo or Ecobright. This coal also produces over double the amount of ash of most other coals, requiring the ash compartment to be emptied every day. This coal is €13/40kg bag delivered here.
Anthracite – This coal is made up of various shaped pieces varying around the size of Polish Doubles, which is also easy to handle even with a small fireside shovel. This coal is the most difficult coal to light based on our experience and is practically impossible to light using just firelighters. With plenty of kindle (around 15 pieces), it will be glowing alight at the surface in about an hour. It takes about 90 minutes to reach the point where the radiators get lukewarm and about 2 hours from lighting for a bucket to be fully glowing red, at which point it is ablaze with dancing blue flames. Once the kindle burns away, this coal gives off absolutely no smoke, but does crackle and spit when further coal is added, so is unsuitable for an open fireplace.
Unlike most solid fuels, this coal burns with a blue flame similar to that on a cooker and gives the impression of it being a gas fire. Like Ecobright, anthracite does not burn as quickly and can burn over a long period of time. Unlike most other coals, anthracite requires at least a bucket worth to burn properly and will easily go out, especially if there is less than a half a bucket worth left in the fireplace. It also needs riddling every few hours to clear the ash below it as otherwise it will smother itself, regardless of the amount of coal in the fireplace.
Based on our experience, Anthracite needs to be burnt 24 hours a day to be worthwhile using, at least in our stove. As this coal leaves no trace of soot, it would be the most economical to burn continuously, especially over a lengthy very cold period. We have successfully burnt this as a mix with Ecoglo as well as Union Nuggets, 2 parts to 1 part of anthracite on top, which helps run the fire longer than either coal alone. This method leaves just a few pieces of clinker in the morning, which we throw on top of the next fire.
Due to the difficulty we have burning anthracite on its own in a similar way we burn other coals, it is difficult to compare the quantity for the equivalent amount of heat, but when we burnt it around the clock over a few days, we used about 2 buckets per 24 hour period with the radiators kept around 50C. Like Union Nuggets, this coal produces a lot of ash and needs the ash compartment emptied at least once daily and sometimes twice daily when burned continuously. This coal is €17/40kg bag delivered here.
Wood – While we burn wood intermittently, so far we have not burnt wood on its own for more than a single day. We generally either use wood to quickly heat the radiators or in addition to coal. When chopped to reasonable size chunks, it only takes about 10 minutes for wood to reach a full blaze and will bring the radiators up to about 60C in about 60 minutes from the time of lighting. The main time we burn wood is if we were away for a day or longer and need to get the chill out of the house when we return. With a smokeless coal fire, we occasionally add a few logs in the evening instead of adding extra coal. This gives a nice blaze, while also giving a good boost to the radiators for a few hours.
As we never burned wood on its own for more than a day, it is difficult to say what it is like for soot. However, whether we burn Ecoglo on its own or as a mix with wood, the amount of soot in the upper section seems to build up by the same amount each time I clean it out. One thing we can confirm is that wood does not burn well when damp or wet and have had bad experience of it leaving a sticky sooty mess due to trying to burn damp scrap wood.
Wood logs with few to no knots do have one advantage in that they can be easily chopped into sticks for use as kindle. A bag of logs will produce several equivalent size bags of sticks, which works out at under half the price of kindling sticks.
Update – 30th September 2014:
I just received an e-mail from someone who had their Serenity 4 Inset stove ceramic glass ruined after just a few months use of Eco Glow fuel coal supplied in Sligo (white bag on right). In just 4 months (Nov ’13 to Feb ’14), the ceramic glass started going opaque and could not be cleaned. By March, the flames could not be seen at all. The door on the right shows the resulting damage, i.e. the wooden panels visible on on the left of the door are just barely visible through the right of the glass.
He contacted his stove manufacturer and supplied them with some samples of this Eco Glow coal. The manufacturer then checked the coal with the ceramic glass manufacturer who then tested the coal. This coal was found to have a sulphur reading of over 5%, which is over 7 times the legal limit for coal in Ireland!
The coal had also corroded the metal inside the stove and likely the chimney liner also according to his stove manufacturer. He reckons if he burned this coal for two more years, he would have had to replace his stove.
When sulphur burns, it turns into sulphur dioxide. If this gas mixes with moisture, such as if the coal is damp or is burned with wood, the result is sulphuric acid, a highly corrosive acid as found in car batteries. The higher the sulphur content in coal, the more sulphur dioxide is produced and in turn the more potent the acid becomes.
For those who import coal from Northern Ireland, it is worth noting that their sulphur limit is 2%, but even still, this person’s coal still had nearly triple that limit. Unfortunately, without a lab, there does not seem to be any way a for a consumer to test the sulphur level in coal.
The Eco Glow coal I burn is from a different supplier (green bag on right), so it’s quite likely that different suppliers use different grades of coal to manufacture their nuggets. Since posting this review two years ago, the lower half of the glass on our stove has started getting fairly speckled, but has little impact on the visibility the flames. With the variety of coals we burn (often to test), it’s hard to say whether our stove glass started speckling due to the coal or just with regular use over the years.
If you choose to use Eco Glow coal, if the bag looks like the upper white bag on the right, do not use it in a stove or enclosed fireplace!
Update – 10th March 2015:
Now that I’ve a faster 10Mb Internet uplink at home, I recorded a video showing how I light the smokeless coal using just two pieces of kindling. Basically, the trick is to add a layer of coal on the grate with firelighter placed on the grate in the middle. Light the firelighter, place two pieces of kindling directly above it and build a pyramid of coal up.
In this video I used a large shovel where possible to reduce the recording time, followed by a time-lapse video to show how the fire progressed over the following hour. At the end of the video, you can see the state of our stove’s glass after several years of burning the Ecoglow. It’s coming to the stage where we’re debating whether to change the glass for the following season.
A lady recently e-mailed me mentioning this Ecoglow coal produces a strong sulphur smell in her house and is irritating her eyes. While it’s due to smoke somehow making its way back into her house, this is another confirmation that this coal has a high sulphur content, at least in some areas. So far I haven’t had any issue with any smell from it, although we don’t have any issue of smoke making its way back into the house, even years ago when we burned the smoky doubles coal. My brother next door says it does not seem to burn as hot this year as last year.
Update – 25th June 2015:
The Irish manufacturer of Eco-Glow contacted me to say that their official product is only sold in the bag shown on the right and that they manufacture it to the Irish Standard and contains less than 2% sulphur. They went on to say that there are various other products being imported as cheap copies that do not adhere to the Irish standard.