Stove Pipe

[5030]

At today's inflated prices, anything you heat with will be expensive...anything.

 

[ruffdog]

I have a 30,000 BTU propane modine type heater near the ceiling of my 2 car garage. Even though the garage is fully insulated, it would take a day to fully heat it up to 60 F deg. The two garage doors and concrete floor really sucks the heat out. The nice thing about the modine is you just turn it on when needed...easy peasy.

 

[CalG]

Neighbor in damp and humid Olympia WA has a complete shop and the wood stove always fired and the shop is very dry but he is retired and in the shop 7 days each week.

He has all the wood he can use for the sawing and splitting.

He told me he couldn’t imagine not having wood and paying for electric in retirement.

wood is good!

 

[ultrarunner]

wood is good!

North America’s abundant natural resource endorsed by President Carter with tax incentives…

 

[CalG]

North America’s abundant natural resource endorsed by President Carter with tax incentives…

And OH SO Carbon neutral!

 

[ultrarunner]

And OH SO Carbon neutral!

Yep… rotting in the forest or up in flames due to a wild fire or keeping the hearth warm on a cold winters night…

 

[5030]

If keeping your butt warm when it's cold out, 'carbon neutral' is the last thing on my mind. In fact, it's dead last anytime.

 

[WinterDeere]

While the condensation was not the direct fault of the heater (it's more due to the difference in temps between outside and inside without proper insulation, vapor barriers, and airflow), it still was a problem.

@ponytug already alluded to this, but the condensation actually is "the direct fault of the heater". Each gallon of kerosene burned produces something like 1.3 gallons of water as a byproduct in its exhaust. Hard to believe, if you're not a chemist, but true. While folks heating their homes with kerosene space heaters in the 1970's probably loved this aspect, free humidification, all that added water is going to cause condensation the next time you let the temperature drop in that space.

My new idea and project to start soon is a pellet stove.

Good choice. Just be aware of the cleaning requirements, and the various issues of different brands. hearth.com has a whole pellet stove forum, and reading through the issues guys seem to have with various models there, I'd be looking first at Harmon.

Pricing stove pipe, the cheapest I have found so far is $350! And that is just the pipe, no other parts like elbows or the cap, etc. This is the DuraVent 4in x 36in chimney stove pipe at $35. (30/3x$35=$350). I'm not even sure if this is the right size pipe! Do I need to step up in size to run that length?

Length dictates static draw, diameter dictates flow. Generally, taller is more of a problem with over-drafting on modern low-flow stoves, as these stoves are typically designed for worst-case min draft. When dealing with wood stoves, those of us with taller chimneys actually have to restrict them down to behave more like a shorter chimney, rather than step up.

And yes, quality pipe is not cheap.

It's actually better to have single wall pipe in the inside of the occupied space since you get more heat that way.

Not since at least the 1990's. This advice comes from older (think 1970's) wood stoves, that threw damn near half their heat up the chimney, and there were cases where you could take heat off the pipe without too much penalty. There were even special heat-exchanger stove pipes designed for this purpose. In many cases where too much heat was removed, they caused massive creosote deposition problems, and eventual chimney fires.

The exhaust from any wood or pellet burning appliance carries both water vapor and compounds that when condensed will deposit creosote. If you allow the exhaust gas temperature to drop below 200F before it reaches the top of your chimney, you are likely to experience this problem, as that's near the condensation point of water at typical reduced chimney pressures.

Older stoves kept chimney temperatures so high, that yes... you could take a good bit of heat off the chimney and often still stay in this safe 200F+ range at the top of the chimney. But the old stoves were only throwing this much heat up the chimney because they had absolutely terrible efficiency.

Modern stoves are much more efficient (80%+), and thus exhaust gas temperatures are much, much lower. And the lower you run the stove, such as using a low setting when you're not actually in the shop, the more you're flirting with this. So, if your stove manufacturer recommends double-wall or insulated pipe, this is the reason why. Using any mechanism to remove more heat from the exhaust can lead to creosote deposition, and even chimney stall and CO into the structure. And since you mentioned having a taller chimney, this problem is amplified, as the exhaust has even more time to cool on its long way to the top. Don't do it.

 

[HawkinsHollow]

@WinterDeere Some food for thought there! Excellent info! Thanks

 

[5030]

I'd be looking first at Harmon.

Keep in mind that Harmon is by far the most expensive solid fuel burning units on the market today and far as I know, none of them are corn biomass capable.

In my opinion, Harmon's are pretty units but I'm not into pretty, I'm into functional and all of them basically do the same thing and that is rapid oxidation of a solid fuel source and produce heat and all of them must be at least 80% efficient or again they cannot be sold domestically.

I've been using biomass stoves as supplemental heat for over 30 years now so I'm very experienced with it. I own 3 units, all corn (biomass) capable and they are all 100% solid state (computer controlled) and they all run on remote thermostats as well. Strictly for supplemental heat and I'd never consider them as a primary heat source, simply because the cost of manufactured pellets today is prohibitive and I frequent all the biomass forums and have for decades.

I need to add something of importance and that is...

There are only 2 manufacturers of pellet / corn venting, Simpson Duravent and Selkirk Industries and always keep in mind that they DO NOT interchange. Each manufacturer uses their own proprietary interlocking design so you CANNOT mix them successfully as they won't interlock with each other and both are expensive because the design on pellet venting entails a stainless inner liner with a defined air space between the stainless inner and the galvanized outer shell. All pellet venting has to be UL approved and certified by Warnock-Hershey testing labs or it cannot be sold in this country.

 

[5030]

Additionally... Biomass (pellet and corn burning appliances) don't produce creosote if vented and operating properly.

All they produce is fine fly ash, no creosote what so ever and why they mist be maintained religiously and often as the fly ash will plug them up. When I'm using mine, they get cleaned internally at least weekly and I take apart the external venting and clean it inside a couple times during the heating season plus my external venting has a removable fly ash trap at the bottom of the vertical outside pipe run that gets dumped weekly and of course all of that is extremely messy.

Like I said previously, with the cost of manufactured pellets today, they are almost cost prohibitive to operate unless you can buy pellets in truckload quantities which I have in the past. truckload quantity is usually 22 skids of pellets delivered on a tractor trailer and the skids average 2000 pounds each so you need the proper equipment to unload them as well plus they have to be stored inside as if they sit outside, they attract moisture and damp pellets turn to mush in the bags which are usually 40 pounds per poly bag. Once they get soggy with moisture, they are not useable as a biomass stove needs it's fuel at or below 7% RM to combust.

 

[CalG]

Additionally... Biomass (pellet and corn burning appliances) don't produce creosote if vented and operating properly.

All they produce is fine fly ash, no creosote what so ever and why they mist be maintained religiously and often as the fly ash will plug them up. When I'm using mine, they get cleaned internally at least weekly and I take apart the external venting and clean it inside a couple times during the heating season plus my external venting has a removable fly ash trap at the bottom of the vertical outside pipe run that gets dumped weekly and of course all of that is extremely messy.

Like I said previously, with the cost of manufactured pellets today, they are almost cost prohibitive to operate unless you can buy pellets in truckload quantities which I have in the past. truckload quantity is usually 22 skids of pellets delivered on a tractor trailer and the skids average 2000 pounds each so you need the proper equipment to unload them as well plus they have to be stored inside as if they sit outside, they attract moisture and damp pellets turn to mush in the bags which are usually 40 pounds per poly bag. Once they get soggy with moisture, they are not useable as a biomass stove needs it's fuel at or below 7% RM to combust.

All the outlets for wood pellets around here store the pallets of pellets (ha ha) outdoors, un-covered.
Must be a New England thing, or modern packaging.

I have three pallets under tarp....

 

[oosik]

I had a big 'ol Modine hanging ceiling heater in our garage in AK. Heat came from a hot water loop off our natural gas furnace. It must have been 100K BTU, at least. It would bring the garage to 70F in less than an hour.

The garage was only 20x30 and well insulated. Including an insulated door.

 

[WinterDeere]

Keep in mind that Harmon is by far the most expensive solid fuel burning units on the market today and far as I know, none of them are corn biomass capable.

If corn biomass is important to you, then by all means... but I came to the conclusion that Harmon is one to consider from spending way more time and years at hearth.com than I've ever spent here, and hearing what the pellet burners there say.

That said, I'm a cordwood burner, I don't run pellet stoves. So I'm going on advice I've gathered from others' experience, albeit vast experience over many years, not my own.

In my opinion, Harmon's are pretty units but I'm not into pretty, I'm into functional and all of them basically do the same thing and that is rapid oxidation of a solid fuel source and produce heat and all of them must be at least 80% efficient or again they cannot be sold domestically.

Pretty and functional are not necessarily intertwined. Maybe they're pretty, maybe they're not... and maybe beauty is in the eye of the beholder. That's all irrelevant.

My conclusion that Harmons were one to consider came from watching the number of posts from the pellet heads, about various troubles they're having with many other brands, and several of them eventually upgrading from other brands to a Harmon. I don't think that cosmetics were their primary reason, nor did I ever say they were the only brand to buy, just the one I'd be shopping first among many.

I prefer not being tied to pellet supply issues, and so I run wood stoves, albeit multiple wood stoves at the same time, heating this huge old barn of a house. My wood fuel is free, and always available, but it cannot self-regulate day to night like a pellet stove can. But my cordwood stoves can run 30 - 40 hours on a single load, so if the OP is in a position where they're available to tend the thing at least once per day, it's worth consideration.

 

[ponytug]

Additionally... Biomass (pellet and corn burning appliances) don't produce creosote if vented and operating properly.

All they produce is fine fly ash, no creosote what so ever and why they mist be maintained religiously and often as the fly ash will plug them up. When I'm using mine, they get cleaned internally at least weekly and I take apart the external venting and clean it inside a couple times during the heating season plus my external venting has a removable fly ash trap at the bottom of the vertical outside pipe run that gets dumped weekly and of course all of that is extremely messy.

Like I said previously, with the cost of manufactured pellets today, they are almost cost prohibitive to operate unless you can buy pellets in truckload quantities which I have in the past. truckload quantity is usually 22 skids of pellets delivered on a tractor trailer and the skids average 2000 pounds each so you need the proper equipment to unload them as well plus they have to be stored inside as if they sit outside, they attract moisture and damp pellets turn to mush in the bags which are usually 40 pounds per poly bag. Once they get soggy with moisture, they are not useable as a biomass stove needs its fuel at or below 7% RM to combust.

I agree that no to low creosote production has something to do with operation and venting. Creosote is a result of incomplete combustion, aka smoke, and water. Pellet stoves do better than older wood stoves, but deposits can be a problem both from particular stoves designs and operation, and from the quality of the input pellets, e.g. water content and the particular properties of the biomass in the pellet. e.g. corn vs sawdust vs bark vs fiber.

Corn, due to its protein, aka amino acid, content and its typically relatively high water content, produces particularly corrosive combustion gases, requiring stainless steel pipe, and regular cleaning. I understand the appeal, but as I wrote above, the composition of the biomass for the pellet makes a difference.

All the best,

Peter

 

[CalG]

An observation:

As last year was the first winter season that the pellet stove ran 24/7 the entire heating year, and the warnings and information posted on this thread, I JUST NOW disassembled the 6 foot long, 4 inch dia., single wall galvanizedmetal flue pipe that connects the stove to the masonry chimney for inspection and cleaning.
What did I observe?

Perhaps 1/2 cup of fine dry fly ash, lightly adhered to the pipe inside..
Less than 1/4 cup of the same within the chimney thimble. All material dropped out with a light tapping of the pipe with a small stick. The thimble swept clean with a hand dust broom.
I used the shop vac to remove the small amount of ash at the first elbow from the stove at ground level. Observation of that section shows clean metal after.
The burn volume last season was about a ton and a half. Pellets are labeled "premium", not that I know what that describes.

After 30 plus years of cleaning pipes for the downstairs wood stove. I'm impressed and satisfied with the clean burn of this pellet stove. A Breckwell.

 

[5030]

All pellet vent has a stainless steel inner liner, the only difference between venting approved for combusting corn versus combusting pellets only is the grade of stainless used. That's it.

In reality there is no difference between 'Premium' pellets and normal pellets. Most are produced from wood that is deemed not useable for anything else, like wood slash or recycled wood pallets for instance.

Myself, I use 6" pellet vent, 4 from the units to the outside with a 4-6 increaser with an open bottom I install a short piece of venting into with a removable cap abd I use that for a cleanout.

I completely take apart the venting every spring and pressure wash it inside and add Purple Power in a spray bottle prior to, to remove all traces of fly ash.

6" is better than 4" simply because 6" produces a better natural draft and helps the units extract the by products of combustion more efficiently. 6" is also more expensive than 4"

I run Duravent only, not Selkirk. I prefer the Duravent positive interlock.

and... the units get completely taken apart every spring and cleaned as well and I remove the induced draft fans, drive motors and clean and lubricate them as well. Remember all of them rely on mechanical means to control and maintain combustion. The internal mechanical components of any unit live in a dusty, somewhat abrasive atmosphere inside the cabinet so bearings and rotating components need to be maintained and lubricated.

Like I said, been doing this for 30 years now and I've already experienced most all the pitfalls of ownership. Replacement components are always expensive so much like a tractor, timely maintenance is paramount.

I also have extra burn pots for all of them and I remove the burn pots weekly and replace them with a cleaned one and I soak the burn pots in a bucket of water. That loosens any carbon buildup on them and allows me to remove it with a putty knife and / or a scotchbrite pad.

In my situation this year, propane is actually less expensive than biomass, consequently, the unit in the house will probably not get used at all. The pair in the shop will but sparingly because I also have propane fired in floor heat (PEX) in the shop.

 

[Avenger]

There is much that I have learned from this thread and from my own research. For example, it never dawned on me that burring a kerosene or diesel heater would be the cause of so much condensation. After doing some pondering and discussing the issue with SWMBO, we have decided to go in an entirely different direction.

This year, since I wont actually be home much, I will use the kerosene heater when I need to work out there. The things that I'm afraid will be damaged due to the cold, we will move into one of the room with electric heat.

Once we have the funds saved up (I hate credit) we will purchase a large natural gas shop heater. I am hoping to install this by this time next year. At $1800, it is not something I can run out and purchase right now. Once we get the heater, we will plumb in the natural gas line. My house is pretty close to the shop where the gas line enters the house. It's about 30ft. That will be another expense as I have limited experience with installing gas lines and do not have the tooling to do it. I can however, dig the trench.

Once the natural gas heater is up and running, we will then shift our focus to insulation. Right now, the shop has a little insulation, if you can call it that. Its that thin layer of foam and plastic between the wood supports and the sheet metal. The roof also has this, but its all so thin and barely does anything. Pricing out insulation these days is mind boggling expensive! So, this will be done in sections when I can afford it, until the job is done.

We think that doing it this way, spending the money on something that we don't have to fuel, clean, worry about, etc is the way to go. It's expensive, but offers peace of mind.

I thank you all for the advise. You honestly saved me from doing something I'd later regret. This forum is amazing! I've learned so much here. Thank you all again!!

 

[ultrarunner]

I'm sure there are variations of approved underground pipe for gas...

My last install required a pipe that was coated in a yellow plastic wrap over a almost tar like coating...

I was replacing with a permit 50 year old black iron that rusted out and found by the odor and sound of gas escaping...

 

[CalG]

There is much that I have learned from this thread and from my own research. For example, it never dawned on me that burring a kerosene or diesel heater would be the cause of so much condensation. After doing some pondering and discussing the issue with SWMBO, we have decided to go in an entirely different direction.

This year, since I wont actually be home much, I will use the kerosene heater when I need to work out there. The things that I'm afraid will be damaged due to the cold, we will move into one of the room with electric heat.

Once we have the funds saved up (I hate credit) we will purchase a large natural gas shop heater. I am hoping to install this by this time next year. At $1800, it is not something I can run out and purchase right now. Once we get the heater, we will plumb in the natural gas line. My house is pretty close to the shop where the gas line enters the house. It's about 30ft. That will be another expense as I have limited experience with installing gas lines and do not have the tooling to do it. I can however, dig the trench.

Once the natural gas heater is up and running, we will then shift our focus to insulation. Right now, the shop has a little insulation, if you can call it that. Its that thin layer of foam and plastic between the wood supports and the sheet metal. The roof also has this, but its all so thin and barely does anything. Pricing out insulation these days is mind boggling expensive! So, this will be done in sections when I can afford it, until the job is done.

We think that doing it this way, spending the money on something that we don't have to fuel, clean, worry about, etc is the way to go. It's expensive, but offers peace of mind.

I thank you all for the advise. You honestly saved me from doing something I'd later regret. This forum is amazing! I've learned so much here. Thank you all again!!

If I had Natural gas available, burning kerosene or wood pellets would not even enter considerations.