Which is better? Secondary Burn vs Lazy Flame

[psilv]

Hi all. I am new to the forum. There is some great info on here. Hopefully this post/responses can help others as well. Thanks in advance for any and all help you can give. Sorry for the length of the following post but I want to be as explanatory as possible.

Growing up I had a wood stove for many years, but was never the one in charge of maintaining it or paying attention to specifics. I would just throw wood on when my parents weren't home and that was that. So now its time for me to learn. My girlfriend and I moved into our new home which has a PE Super 27 stand alone wood stove in place. Lovin it so far, seems like a good stove from what I can tell from my limited knowledge.

I have been searching and reading for days on this forum but cannot seem to find a post that is specific enough to answer my question... With a fresh load of wood, if I cannot achieve both a secondary burn and a lazy flame, is it better to aim for a secondary burn regardless of how fast I am ripping through the load of wood, or should I ignore the secondary burn and get the flame to be as "lazy" as possible as quickly as possible to prolong the burn time? I am trying to find a sweet spot between using the woods BTU's as efficiently as possible, while getting the longest burn time. I seem to have to run the primary intake open at least half way with a fresh load in order to achieve the secondary burn (which I think is normal to an extent), but doing this rips through wood quickly and severely shortens the time between reloads.

Once I achieve secondary burn, I attempt to go shut the primary intake slowly and in intervals until I get a "lazy" flame. Sometimes the "lazy" flame will hold fine and I just leave it be (although there is no secondary happening) until I can shut the primary 95 - 100% closed.... but other times the lazy flame only last for a few minutes until its not putting out any heat and it starts to smolder. I have to open the primary again to get it going. This seems to be the cycle I have been stuck doing for the first hour or so after reload (unless I just leave primary open which I don't want to do). Keep in mind I am far from okay with having to reload this stove after only 3-4 hours. I am not trying to go through that much wood. I am using wood mainly to save money and if I start going through a lot of it, it will defeat the purpose.

My regular time so far between reloads is 6-8 hours, preferably 8 - 10 if I have some good coals going and it isn't too cold out, but 10 is very very rare, almost never. I am not too concerned with the house cooling off a bit in between reloads, my girlfriend and I do not enjoy a hot house. So... how can I get the most out of a load of wood without sacrificing the reload time too much or sending too many BTUs up the chimney? Would I be better off leaving the primary open for an extended period of time during the beginning portion of the burn to achieve secondary burn and burning the load that much faster? Or should I try to get to a lazy flame as fast as possible, ignore the secondary burn, thus increasing the burn/reload time by a couple/few hours? I do understand the secondary burn represents unused energy/gas, so by seeing secondaries it is the most efficient burn, but to achieve that I am losing overall burn time and reload time. I feel like my obsession with trying to prolong burn time/reload times in an attempt to use as little wood as possible, is causing me to waste a lot of the first hour of my burn. Unless prolonging burn time provides more benefit than secondary burn?

I am willing to sacrifice a 1/2 hour or so between reload times if it means not babysitting this stove and adjusting air intake constantly for the first hour. Once an hour or two has past, I can shut the air intake 95%-100% and get a lazy flame with a secondary burn for a little bit, and then a nice lazy flame putting off good heat for hours after that. The issue/question I have above applies to the first hour or two after a fresh reload, as I can't find a good in-between, between having the stove ripping hot, and prolonging the burn time as much as possible. The moisture content of wood I am using is between 12 - 17%. I do not know any other specs on the stove unfortunately.

Previous owner of the home did not have temp gauge installed on the flue and no stove top temp gauge either. Maybe I am not achieving a hot enough temp before closing primary? I am reading peoples posts on here saying after they reload with seasoned wood and a good bed of coals, they let the primary rip wide open for 5-15 minutes give or take, shut the primary down completely, and then have a nice lazy flame with secondaries without issue. Do I have to choose between either a secondary burn or a lazy flame for the first hour or two, or is there an in-between? Is there even such thing as being able to have a secondary burn with a lazy flame for the first hour or two after fresh reload, or is this not achievable until most of the gases have burned away after a couple of hours? Is it okay to adjust primary until there is a lazy flame for the first portion of the burn, or is this wasting mass amounts of BTU's by not getting to secondaries? Achieving longest burn time is my absolute priority, but not if I am wasting that much potential energy, and not if there is a better way that shortens the burn cycle/reload time by only a little bit.

Thanks

 

[begreen]

Had to insert some paragraph breaks in order to read this.

Go for the lazy flame. Then wait, the fire will regain strength as long as the draft is sufficient. Then close down the air again to get the flames lazy. Instrumentation is a big help in knowing how the fire and stove are performing. Take a look at this thread to see the correlation between stove and flue temps as the air is closed down in increments.

Thread 'Starting a fire and running an EPA stove'

Jan 17, 2020

Questions about starting a fire and avoiding a runaway stove come up so frequently I decided to document starting our stove. This is a Pacific Energy Alderlea T6 with about a 3 cu ft firebox. The stove is connected to a straight-up, 20' interior flue. The outside ambient temperature is 34ºF. The blower was off all the time for these shots. The firewood is douglas fir at about 17% moisture content. This is a N/S loading. An E/W loading start will follow.

NOTE: as testing will show, the older Condar flue thermometer is reading low. It needs recalibration.

There are 3 instruments shown.

1. ...

• begreen
• Replies: 89
• Forum: The Hearth Room - Wood Stoves and Fireplaces

• 

 

[psilv]

Had to insert some paragraph breaks in order to read this.

Go for the lazy flame. Then wait, the fire will regain strength as long as the draft is sufficient. Then close down the air again to get the flames lazy. Instrumentation is a big help in knowing how the fire and stove are performing. Take a look at this thread to see the correlation between stove and flue temps as the air is closed down in increments.

Thread 'Starting a fire and running an EPA stove'

Jan 17, 2020

Questions about starting a fire and avoiding a runaway stove come up so frequently I decided to document starting our stove. This is a Pacific Energy Alderlea T6 with about a 3 cu ft firebox. The stove is connected to a straight-up, 20' interior flue. The outside ambient temperature is 34ºF. The blower was off all the time for these shots. The firewood is douglas fir at about 17% moisture content. This is a N/S loading. An E/W loading start will follow.

NOTE: as testing will show, the older Condar flue thermometer is reading low. It needs recalibration.

There are 3 instruments shown.

1. ...

• begreen
• Replies: 89
• Forum: The Hearth Room - Wood Stoves and Fireplaces

• 

Thanks for the response begreen. This is a very good simple explanation and you have explained it in a way I did not think to go about it. This approach has worked well the last couple of days.

I have been ignoring the secondaries completely for the first hour or so and only paying attention to how the flame looks. It has resulted in a more steady and consistent start up for sure. Although the start up is much better, I am still obsessing with how much more heat I am losing up the chimney now. It kills me to leave the primary on a more open position for longer periods of time until the flame has time to regain strength, but this does seem to be the way that is working best. Now I'm not messing with the primary constantly for the first hour or two.

It seems like it's reducing the burn cycle time by a bit (as expected), although it's not reduced by enough to be bothering me. I am not seeing much of noticeable difference in the temp of the house, which is nice (and relieves some worry about how much more heat I'm sending up the chimney). If I reload by set intervals, say every 6-8 hours like I have been doing, regardless of how the fire looks or regardless of the temp of the house, I am still burning the same amount of wood overall.

I'll more than likely keep doing this routine through this batch of wood since it is working well. I'll see how future batches react to this same routine and adjust from there. Hopefully future batches will allow me to close the primary sooner, but until then.

Thanks again for the advice 👍

 

[Gray_Day_On_Oregon_Coast]

I ran a Pacific Energy Super 27 Series D EPA Phase II for eight years with a, I dunno, 15' chimney, prolly, and then moved it to a house with a 25' chimney. Here's what I learned through much trial and error. Your mileage may vary.

With a stove top thermometer, you want at least 300 degrees for proper secondary ignition and to get out of the creosote zone. 400-500 is better. With a healthy bed of coals, close it off entirely, reload it, run it wide open until you've got a fast burn and most of the wood is on fire, then close it down 90 percent. You'll get a nice "fire cloud" up top with smaller flames below. For overnight, do the same thing, but close it off all the way and you'll only have small flames.

One key thing is the stove and your flue need to be well warmed up. You can't get a good, efficient burn until after an hour or two.l of use. The flue is the engine that drives the stove by drawing air through. If you have single-wall flue pipe, upgrading to double wall is going to give you much stronger stove performance and reduce creosote buildup.

Type of wood is key. Obviously you need seasoned wood, but you're only going to get the kind of burn times you want from oak, ash or similar types of hardwood. I burned mostly shore/lodgepole line, spruce, fir and alder. With alder, technically a hardwood, Fully loading the stove to the brim, I could get 8 hours, but it'd be down to a weak bed of coals. Softwoods were more like 4-6.

Keep in mind a couple things: wood stoves are space heaters and unevenly heat a house and you're also always going to have temperature variations in an ebb and flow with reload times.

This series of stoves has three air intakes: Boost air that comes out below the glass, the main "air wash" intake that comes from above and goes across the glass, and the secondary ignition intake that provides air to your baffle. You can shut off the primary and secondaries, but the boost air is always open. If you're over firing or truly want to stop your air intake for the slowest burn possible, you can actually block the boost air off with a magnet from below by the ash pan- at your own risk.

All that being said, as begreen mentioned, having both the small flames and the fire cloud is best, but for longevity, only the fire cloud, i.e. just burning smoke, is going to give you the longest bed of coals possible, but not your best heat. Also keep in mind the Super 27 has a smaller firebox than other stoves you might be used to, and you just can't stuff that much wood in. It's only rated for 1800 square feet and I think the furevox5is 1.96 cut feet vs. the 2+ of a lot of other stoves.

HTH

 

[begreen]

There are several changes since that old Spectrum. In particular, the secondary regulation is quite different now with the EBT2. It is no longer linked to the primary air control. The boost air is simple to block off on the stove. It's a small hole in the front and center under the ashlip. Some foil tape or a magnet makes an easily reversible correction.

 

[Gray_Day_On_Oregon_Coast]

The boost air worked exactly the same on mine, but the primary/secondary intake was controlled by one lever.

 

[begreen]

The boost air worked exactly the same on mine, but the primary/secondary intake was controlled by one lever.

Yes that was a nice system. I liked it. The baffle is different now too.