Introduction and a question

[Jim K in PA]

Hello all,

After several weeks of reading and lurking here, I finally signed up. I will strive mightily to avoid asking the usual questions, but I make no promises regarding asking dumb questions . . .

As it seems customary to do so, I will provide a (hopefully) brief summary of my situation/plans.

We currently have a farmhouse in the Poconos that was built in three major phases; c1815, c1860s, c2005+. It is now ~2700 gross sq. ft. on a not quite full, unfinished basement, with an unfinished attic, and new slate roof. I have done 98% of the renovation work (see my incomplete web site - link below sig). We currently heat with oil fired HWBB on 4 zones. It is an EFM furnace c1997, in excellent condition, with a HW coil. There are 4 of us in the house, our two boys being 13 and almost 16.

Given that our oil consumption is hovering around 1200 gallons/year, economics dictate that we are going to switch to a wood burner for primary heating, with the oil burner for b/u. I also want to heat my 24x36 two story garage/wood shop, and a yet to be built greenhouse attached to said garage, and perhaps heat (episodically) my bank barn/auto shop (22x32 upper only).

We are located on ~10 acres, adjacent to a 70+ acre farm. There is a subdivision nearby, but the closest house is more than 400' away. We are not located in the subdivision.

After doing my research, and agonizing back and forth, I intend to go with my original plan, which was to install a standard OWB. I considered a gassifier (after learning about them here), but given that my supply of wood is almost free, but of varying quality and seasoning, I do not think I can operate a large gassifier in a way that would take advantage of it's efficiency. I also need the single point of operation with the heat distributed to the different buildings to make this work for me.

I have the equipment and infrastructure to handle the volume of wood I will need, and am not afraid of work. So, I will be installing my system this summer, and will work hard to get the oil needle out of my arm.

So, what about my question? I have a farmer friend in Berks County that installed an OWB last year. He is a cheap SOB, but very resourceful, and very competent. He used standard black poly tubing for his distribution lines. I think he is asking for trouble. Has anyone else seen this used before? His is an unpressurized system, but the pipe is still seeing temps well beyond what it is rated for. Is he smart, or not?

Thanks for listening, if you have gotten this far.

Jim K in PA
www.pennbrookfarm.com

 

[Eric Johnson]

Welcome to the Boiler Room, Jim.

Cheap SOB with an OWB. I like that! Probably a good description of more than a few old coots.

I think he's asking for trouble. Maybe if he just buries the pipe without insulation it will never get hot enough to melt. Otherwise, I'd say its days are numbered. You'd think he could at least have used CPVC which, while banned for hydronic systems in many jurisdictions, is rated at 180 degrees.

 

[Jim K in PA]

Eric - LOL - he is a great guy and a good friend. He has a OWB built by local mennonites. I have yet to get a good look at the thing, but I will be taking a tour of his and some others before I decide if it is right for me. I know he runs his water temps a bit lower than typical, but he seems comfortable, and happy with the setup. Of course, he lives alone now (wife was killed in a tragic farming accident a few years ago) so he has no WAF to consider

Pook - yep, being an engineer, I wondered about the FS for the pipe. His rationale about it's appropriateness is flawed, but he has it in and working, none-the-less. He did insulate the pipe himself, somewhat. I don't think it sees much more than 150-160 degrees, but I (and he) could be wrong.

I plan on using PEX with foam in the trench for my installation.

Thanks for the input.

 

[Nofossil]

I used standard black plastic for the buried lines from my solar hot water panels, not realizing that they would reach 180 degrees. My original panels only reached 130, so I thought I'd be OK. The plastic gets really soft, but it's held up so far. Don't know what would happen if it was under pressure, though. I have a vision of it expanding like a balloon. The plastic fittings are having a worse time of it, and I'm replacing them.

 

[leaddog]

years ago I had a hasha with cpvc pipe and one time I over heated it. It was buried in sandand i thought I would be ok, well that stuff got to be abought 6in around and abought .010 thick before is sprung a SMALL leak. It was imposible to repair as even 100ft away it swelled up so no fittings would work. Only talking 20 to 30 over temp limit. About 200 to 210* Buy pex its not much more and it is easier to work with.
leaddog

 

[jebatty]

My OWB, now history, use CPVC for some of the plumbing, lasted about 4 years and then started to crack.

Jim K - I think you are making a mistake in going the OWB route. Although I enjoy cutting, splitting, stacking wood also, there's more to life than that. Using about 1/3 the wood with a gasifier frees up lots of time to do other things. Plus, efficiency is something we all need to be more in tune with. Waste never makes sense. Keep in mind the cost is competitive. Plus - plus: you will be the talk of the town, proud of what you own, and you will spread the word to others. Please re-think you decision.

 

[Willman]

but given that my supply of wood is almost free, but of varying quality and seasoning,

I would seriously look at a gasifier. Still cut & split double the wood to satisfy your exercise requirements. Then season it and sell it to the residents of the sub division next door for the big bucks. Use the proceeds from that endeavor to pay off the gasifier.

Will

 

[Jim K in PA]

Jim & Will,

I would love to go with a gassifier, but I am really concerned about whether I could actually run it in a manner that would allow it to operate at it's potential efficiency. The cost of the boiler is not the issue. My budget is certainly NOT unlimited, but I am willing to spend the appropriate funds to purchase the most appropriate equipment. However, I am certainly willing to be persuaded that my options are more than an OWB. Let me lay out my understanding to this point of why a gassifier is not for me:

1. A gassifier is most efficient at maximum capacity. They do not like to be throttled down/idled.
2. Given the above, it is best to operate them at max cap for shorter durations, and store the excess heat for later use or more prolonged distribution
3. I do not have the ready means to build a large scale storage system, and am not really interested in doing so.
4. With the exception of the CB E2300, I would need to place the gassifier in an outbuilding (I could possibly solve this)
5. I want to heat several seperate buildings with diverse demands. Again, with the exception of the CB E2300, this appears to be a deal breaker for the gassifiers I am aware of.
6. Fuel - Unless fed optimum fuel, a gassifier will not deliver the efficiency it is capable of.

I DO NOT claim to be fully educated on all that exists in the world of gassifiers, but after weeks of reading hundreds of posts, I have come full circle from OWB to gassifier to OWB.

PLEASE do your best to convince me otherwise by addressing my concerns regarding the above brief list of obstacles. This discussion may warrant a seperate post . . . ?

Thank you guys.

 

[webbie]

If you are an engineer, you probably understand efficiency.

The total efficiency of a OWB could be as low as 20-30%. The pollution output could be as much as 10-20x as much as a crude appliance - if those don't convince you......not much will. That means more wood....more work, etc.

As you mention, Central has a high efficiency OWB, which might suit you.

EVERY wood burning central heating system works best at max or close to max burn, no exception that I know of! Even without storage, a downdraft system will vastly outperform 200 year old "wood in a water jacket" technology. Same with the optimum fuel. Green wood is gonna give lower efficiency in any appliance.

So all of the "cons" in your list are applicable to every type of system.

There was a post recently from some folks who modified OWB with refractory to increase efficiency. I think the info came from a post at http://www.woodheat.org

 

[heaterman]

Your friend is not only cheap and resourceful, he's also a fool. Standard PE pipe will and does fail with downright boring regularity when used for that purpose. Believe me, I have seen enough of it used by the wood ticks up here in Michigan. I think I can recall at least 4 different basements with the fluid contents of the boiler lying on the floor............

If he's your friend, advise him to change his tubing before he has a failure.

 

[Reggie Dunlap]

A couple of thoughts:

-You are the first guy I know of who is willing to pay the cost of a gasifier, but wants an OWB. My advice is to do some more research on how much wood you will burn in an OWB versus a gasifier. It takes a lot of wood to run an OWB, like maybe 10-15 full cord a year. Some guys up here burn 15-20.

-Don't believe any OWB saleman's efficiency numbers. You will never see the actual efficiency they claim.

-Tell your buddy his tubing will fail, and it will most likely be sooner rather than later.

 

[Jim K in PA]

Craig - I do understand efficiency (and the lack of it) and concur with your comments. EVERY combustion based heat generating appliance, regardless of fuel type or final output (stoves, turbines, IC engines, etc.), will operate most efficiently at a specific rate, almost universally at maximum heat output (transfer). The concern I have is the transition from high to low states of operation with gassifiers. I have to tell you, relighting the box EVERY day sound like a PITA. I am agonizing over the direction to take BECAUSE of the differences in efficiency versus the PRACTICALITIES of actual use and application. Distribution of the heat is one thing you did not address. Are there gassifiers that are large enough to be zoned for different buildings other than the new CB unit?

Heaterman - despite your disparaging comments about my friend, I appreciate your warning. I was/am also concerned about a piping failure, and have already suggested that he will need to replace that piping soon.

Reggie - The economics of keeping my family warm are dictating my interest in heating with wood. I have no desire to throw money at an alternative heating method, but 1200 gallons of oil annually at $5/gallon makes it easy to justify researching ALL my options. I am not looking for a way to rationalize a decision already made - I have not purchased anything yet. I am also aware of the "creative" marketing used by the OWB manufacturers, and have been researching them with a full understanding of the fundamental limits they operate under. I also have been observing the practical application of these units, and have seen the good, bad and ugly of them.

Gentlemen, I knew before posting that this was a knowledge base of substantial proportion. However, I was not fully aware of how substantial the prejudices against anything other than WG would be. I will keep reading, researching, and learning. At this point though I will refrain from posting unless I have a question about a WG solution. I apologize for the distraction.

 

[ISeeDeadBTUs]

1. A gassifier is most efficient at maximum capacity. They do not like to be throttled down/idled.

Irrespective of type (Traditional OWB, refractory mass-naturally aspirated gassifier, forced induction downdraft gassifier) efficiency will suffer with iding.

4. With the exception of the CB E2300, I would need to place the gassifier in an outbuilding (I could possibly solve this)

These CB's must be great. So great they fail to put them on their website. What do you seriously expect the cost of a centralized boiler room with a storage tank to run?

5. I want to heat several separate buildings with diverse demands. Again, with the exception of the CB E2300, this appears to be a deal breaker for the gassifiers I am aware of.

Before you write off multiple buildings with a gassifier, talk with anyone in the business that deals with folks across the pond. I believe a central heating plant feeding multiple buildings is more common there. As are buffer (as opposed to storage) tanks. Just my unprofessional opinion, you get multiple buildings calling for heat at the same time, NO unit is going to keep up unless it is terribly oversized.

6. Fuel - Unless fed optimum fuel, a gassifier will not deliver the efficiency it is capable of.

If your back is that healthy, cut as much as you would need for the CB the first two years. At the end of two years you'll have year 3 nearly complete by burning the more efficient technoligy. Then stay a year ahead, doing half the work. This thing about burning less than ideal wood . . . you can probably do it in ANY unit. I don't advise it. MY GW will burn wet wood, though I try to avoid it. When I have to, I mix it with dry hardwood and make sure the wet stuff is up off the coals. This gives it a chance to bake the water out before it has to burn. But that hurts efficiency and creates higher emissions. It will do THE SAME THING in your newly designed, generally un-field tested CB.


Now a couple questions for you . . .

1)What is the heat loss calc for the combined space you plan to heat?

2)What is the 2300 rating?

3)How much fluid does the 2300 hold?

Jimbo

 

[Jim K in PA]

Irrespective of type (Traditional OWB, refractory mass-naturally aspirated gassifier, forced induction downdraft gassifier) efficiency will suffer with iding.

Understood - see my response above.

[quote author="ISeeDeadBTUs]
These CB's must be great. So great they fail to put them on their website.[/quote]

Incorrect - http://www.centralboiler.com/e-classic.html It is a marketing BS bonanza, but it is on their site.

What do you seriously expect the cost of a centralized boiler room with a storage tank to run?

I have not worked up a budget with a storage system. I anticipate than an OWB will cost about $10k when all is said and done (my installation labor). Obviously a storage system will add more - 10%? 20%? I don't know. The storage adds not only cost, but complexity and logistical problems.

Before you write off multiple buildings with a gassifier, talk with anyone in the business that deals with folks across the pond. I believe a central heating plant feeding multiple buildings is more common there. As are buffer (as opposed to storage) tanks.

That is a constructive suggestion. I will, but whom do you suggest I contact?

Just my unprofessional opinion, you get multiple buildings calling for heat at the same time, NO unit is going to keep up unless it is terribly oversized.

I disagree. The same argument could be said for a multiple zone system in the house, which is not correct. The issue is does the time period when the systems are all NOT calling for heat create highly unfavorable consequences in terms of wasted fuel, emissions, etc. with a gassifier as well as an OWB.

If your back is that healthy, cut as much as you would need for the CB the first two years. At the end of two years you'll have year 3 nearly complete by burning the more efficient technoligy. Then stay a year ahead, doing half the work.

I really am interested in working efficiently, both at gathering and cutting wood, as well as consuming it. I have not "written off" gassifiers, but have not yet found a "best path" solution.

This thing about burning less than ideal wood . . . you can probably do it in ANY unit. I don't advise it. MY GW will burn wet wood, though I try to avoid it. When I have to, I mix it with dry hardwood and make sure the wet stuff is up off the coals. This gives it a chance to bake the water out before it has to burn. But that hurts efficiency and creates higher emissions. It will do THE SAME THING in your newly designed, generally un-field tested CB.

In a perfect world I will have perfect fuel, of adequate supply, at my ready hand. Given that such a scenario may not be possible, then I must come up with a solution that can best deal with a less than ideal fuel supply. Mixing green/other-than-ideal wood in with dry, seasoned wood is something I would do regardless of stove type, if/when the situation required it.

BTW Jim, it is NOT my "newly designed, generally un-field tested CB". I have bought nothing yet, and have not decided on WHICH stove to buy.

Now a couple questions for you . . .

1)What is the heat loss calc for the combined space you plan to heat?

House - 69,073
Garage & Shop - 34,028
Bank barn - 42,764
Greenhouse - 27,455
Total - 173,320

This is the total POTENTIAL heat load for all the buildings that I COULD put on the system. The bank barn is not a required load, and may get dropped from the system. The garage/shop/greenhouse would NOT be put on line until next season at the earliest. However, I need to design a system that would accomodate them.

Please understand - I am trying to learn. If heating all the buildings I want to is not practical with a single unit of any type, then tell me so.

2)What is the 2300 rating?

Good question. The BS on the CB web site says that it's "similar to the 6048", which is stated as being a max of 500k.

3)How much fluid does the 2300 hold?

Per the web site, 450 gallons. That is almost 60 gallons more than the 6048.


Somewhere here amongst the disdain for my expression of my original intentions, I am gathering the understanding that I may be able to operate a gassifier without storage much like and OWB. While it is running, it will be more efficient than an OWB, but while it is idling, it will be much like an OWB. My concern then lies in the consequences to the equipment as a result of idling a gassifier. Clogged nozzles? Damaged refrac materials? Bad juju directed at me from the hearth.com brethren?

 

[ISeeDeadBTUs]

BTW, Welcome aboard. No bad juju on my part. I am just generally a sarcastic NY bastard to everyone :lol:

I'm no 'spert on anything we talk about here, but I have used my unit and talked with other peeps that have used their units enough to form a semi-educated opinion. One think I am quite sure of. . . You want to just slightly undersize your unit. This 500kBtu unit from CB is typical operating procedure for CB. The salespeople have always pushed units that are too big . . even when their printed promotional materials say to go smaller. I am heating 4k [] with a 100kBtu unit. But it is all radiant, 30% slab, and all new construction. In my unprofessional opinion, that is why the heat loss calc is so important. GreenWood thought (the funny thing I found, the Salesman was the ONLY one who seemed moderatly honest and helpful in amongst otherwise atrocious customer servce) that, based on a description of my house and the size of my existing oil boiler (my heating contractor couldn't find the heat loss calc they did when setting up my oil boiler), that the 100 would be up around the limit. They hit that one right on. On seriously cold times, If I don't have a perfect oakhard maple fire cranking, it will not supply all the hot water I need. But the oil is there waiting to assist. But for three days this past winter, the 100 was just fine. And the undersizing definitly reduces idling. Storage would probably eliminate it if set up correctly. But before I'll spend money on storage, I'll spend money on SDHW or PV or wind.

Where I live, CB has the greatest market share of users and a pretty good reputation. I have never hung around anyone operating a CB to get a feel for how much wood they eat. I know there is at least one member here that has experiance with using OWBs AND with a gassifier. That member has also seen this new gassifier from CB.

Some members of this forum might be fanatical about gassifiers over OWB, but I've never really seen that. Personally, I think if you operate an OWB correctly, you can minimize smoke.

 

[jebatty]

I have not worked up a budget with a storage system. I anticipate than an OWB will cost about $10k when all is said and done (my installation labor). Obviously a storage system will add more - 10%? 20%? I don’t know. The storage adds not only cost, but complexity and logistical problems.

I don't know current prices of anything, but last summer my Tarm Solo Plus 40 (140,000 btu rating) cost $6000; I added a 1000 gal LP pressurized storage tank for $850; total cost, including some wasted items because of errors, was about $11,000. I did all the labor myself. Storage adds very little complexity, and while it does add logistical issues, it's not exactly apples and apples.

You say the CB has 450 gal of storage, that's extra space and weight, and therefore the "storage tank" is part of the boiler. There is an advantage to external storage in logistics, as you have a smaller boiler with a separate tank: easier to move into location and relocate if needed. You could accomplish the same storage/buffer result with a gasifier and 500 gal LP tank storage; and even do a better job on logistics; and gain the efficiency at the same time.

I'm a proponent of efficiency in whatever form it takes. I keep a minimum of two and preferably three year's supply of wood on hand. Under-seasoned or green wood really shouldn't be an issue ever, as you have adequate wood available. I have 250 ac of woodlands, so wood supply never is an issue for me either.

I had an OWB for 10 years, and have never regretted a moment that it is out of operation. The effort to supply, maintain, and operate the Tarm is much less than the OWB. The pluses so outweigh the minuses that I never have had a second thought, and am very glad I learned of the gasifiers before I replace the OWB with another OWB. I had to fuel the OWB twice a day, almost every day it was in operation, burned at least 15 cords during the winder; and the gasifier normally is once a day on cold MN winter days (around 10), twice a day on really cold days (below -10); otherwise once every other day (20 and above) or once every third day or longer (above 40). The great lack of effort maintaining heat is a huge benefit. My estimate is 5-6 cords this last winter, which was one of the coldest in recent years.

It's you choice, your money, your back, your effort and your perceived value. The decision is all yours. Having had experience with both, I just am hard pressed to imagine why one would choose anything other than a gasifier. My bias is based on experience.

 

[firebird400]

just a note here from Connecticut still tyring top decide on a indoor boiler here but a friend of mine was looking at a owb and Connecticut code is 200ft. from any neighbor also stack has to be higher than any neighbor's buggiest point of building with in a 1000 ft he had the 200 ft. but would ve need 85ft chimney on it

 

[Willman]

That is a constructive suggestion. I will, but whom do you suggest I contact?

Multiple building heating is common across the pond. It is more commonly referred to as "district heating" Do a google on that term. Much info out there. They refer to storage as accumulator tanks. Think of them as energy flywheels, get em spinning on full fire and coast off of storage of the accumulated energy.
I wouldn't take any replies concerning gasifiers personally. The posters touting them have experienced first hand their increased efficiency and are passionate in relaying the info about them.
With the amount of heat load you are designing for you could use the barn or greenhouse for storage (although not transferable). When primary living space is up to temp you could continue the burn and dump the heat into green house, etc. At least you wouldn't be idling.
Will