Justification??

[chuck172]

I'm seriously looking into buying and installing a Tarm Solo Plus 30. I now have a Quadrafire in the basement and a Lopi upstairs.
I have a 1800 sq. foot bi-level with an unfinished (for now) basement.
I have a fairly efficient oil boiler with a super-stor domestic side arm water tank. Hydronic heat with 3-zones.
If I don't use a storage tank the first winter, can I expect to heat my entire house and domestic h/w with the tarm?
Together the woodstoves have aprox. a total of 5 cu. ft of firebox and the Tarm is about 4 cu. ft.
Right now I go through about 5-6 cords of wood burning 1 stove full time and the basement stove in colder weather. Tech support at Tarm figured I should use aprox. 4-5 cords of wood with the Tarm, and it would heat the entire house and plenty of hot water with no storage tank. Is this realistic? Seems too good to be true.
Please give me some opinions. If I buy I want to catch the sale.
Thanks

 

[Eric Johnson]

Welcome to the Boiler Room, Chuck.

I don't own a Tarm, but I'd say yes to the question about heating your house and hot water without storage. The wood consumption numbers sound realistic to me. You get a lot more mileage from a gasifier than you do from a conventional wood-fired boiler. Storage is something you definitely want to plan on installing eventually, however. It makes everything a lot easier. What you'll probably find yourself doing without the storage is making more, smaller fires in the Tarm in order to keep it from idling too much. With storage, you can just load it up once a day (maybe every other day in NJ) and fuggetaboutit.

Hard to believe you'd use less wood with a boiler than a couple of wood stoves, but the Tarm people seem like straight shooters and I don't think they would lowball your wood use estimates too much.

Let's see what the actual Tarm 30 owners have to say.

 

[chuck172]

You know what they say about "it's too good to be true"
The most unbelievable info is in Tarm's paperwork.
"On most days in the winter, you will be able to load the boiler once in 24 hours. In summer you will be able to go 4-10 days between firings to heat all your domestic hot water."
Thats with storage of course.
I would really want someone to verify that!

 

[BrownianHeatingTech]

"On most days in the winter, you will be able to load the boiler once in 24 hours. In summer you will be able to go 4-10 days between firings to heat all your domestic hot water."
Thats with storage of course.
I would really want someone to verify that!

Certainly. You can go a month between firings, if you let me install a large enough storage tank for you

Joe

 

[Jim Post]

I have a solo plus 30 w/o storage heating a 1400 sf 40 yr old ranch with baseboard hydronic heat. The tarm provides heat and hot water all winter in Southern WI. Best investment I have made to date. Storage may come at some point but I am not convinced I need it yet....not sure that baseboard radiators let you use the heat storage as effectively as lower temp emittters like a radiant floor would. We're tied to our tarm in the Winter...stoking 3 times a day when temps drop to the single digits but it is not a big deal....much less stoking and fussing compared to wood stove heating.

 

[chuck172]

Loading about 3 times a day is about par with a wood stove. Does it burn all night? The Tarm people said I should get 4-6 hrs. at maximum burn rate.

 

[Jim Post]

Depending on weather conditions...there have been times where I have not reloaded for 10 hours....it's all based on the heat loss of your structure and the quality of your firewood....I did a heat loss calc using the slant fin software to decide if the 100,000 btus/hr solo plus 30 could handle the 78,000 btus/hr heat loss of my stucture... It does fine. I load the tarm before work....My wife loads the tarm mid afternoon if needed or I load the tarm when home from work and I load the tarm b4 lights out. I think you will be bored with a tarm to tend rather than 2 woodstoves.....might need to take up another hobby.

 

[chuck172]

And I take it your very pleased with the domestic hot water?

 

[Jim Post]

Yep. I don't have the DHW coil in my tarm. I use a sidearm heat exchanger on my electric hot water heater. Works great. I really have no complaints with the tarm...it has already paid for itself with the increasing cost of lp. We went from 1400 gallons of LP in 2003/04 to only needing LP for cooking, clothes drying and minimal LP heating (when/if away) ....less than 100 gallons last year.

 

[jebatty]

You know what they say about "it's too good to be true"
The most unbelievable info is in Tarm's paperwork.
"On most days in the winter, you will be able to load the boiler once in 24 hours. In summer you will be able to go 4-10 days between firings to heat all your domestic hot water."
Thats with storage of course.
I would really want someone to verify that!

I have a Tarm Solo Plus 40 with 1000 gal of storage. Typical winter temps range between 5-20, with periods of -30 to 0, occasionally colder with an occasional warm-up. One load firing per day is pretty normal, sometimes need two, during the normal periods, probably two during the cold periods, and less as the temperature warms. I don't have DHW on my system.

"Winter" is not the same "winter" everywhere. But we're pretty extreme for the lower 48, so Tarm is pretty close to the "average" winter.

 

[chuck172]

Are you saying you don't have the domestic coil in the boiler or you don't make domestic hot water with the tarm at all ?

 

[jebatty]

Both - I use the Tarm to heat my shop, an old barn, very poorly insulated with lots of "let the light in" cracks to the outside.

 

[bbb123]

You know what they say about "it's too good to be true"
The most unbelievable info is in Tarm's paperwork.
"On most days in the winter, you will be able to load the boiler once in 24 hours. In summer you will be able to go 4-10 days between firings to heat all your domestic hot water."
Thats with storage of course.
I would really want someone to verify that!

That info is right on for me. On days when it gets above freezing and 20's at night I burn 1-2 loads of wood in the morning before I go out. Usually I get it going let it burn for 2 or 3 hours then load it up before I go out for the day. On cold days (0-below 0 - teens during day) I have to keep it fired all day cause I have baseboard and to keep the house warm I need 160-180 tank temps. Summer time when wife and 2 young daughters are home I get 5-7 days, when they goto camp I can get 10 days (I dont mind luke warm showers).

 

[chuck172]

bbb123, on the real cold days, how many times do you actually load the stove? How big of a house are you heating? I'm really trying to justify the cost. Pretty remarkable you get 5-7 days and even more in the summer!! Thats with one load of wood at high burn?

 

[bbb123]

bbb123, on the real cold days, how many times do you actually load the stove? How big of a house are you heating? I'm really trying to justify the cost. Pretty remarkable you get 5-7 days and even more in the summer!! Thats with one load of wood at high burn?

About 2400-2500 sq ft. Cold days anywhere from 2-4 times it depends on the tank temp. If its right up to 180 I only throw a half a load in during the day and at night before bed load it right up. Summer burns are usually 1 - 1 1/2 loads I usually run tank down to around 120 and try to get it around 160-165. I use "sub par wood" in the spring fall summer. By sub par its still dry its usually soft maple, birch or old wood thats getting a little punky. I save the oak, hickory, elm, and ash for winter for the longer burns.

 

[chuck172]

bbb123
Looks like I'm heading towards a set-up like yours. Solo 40 and maybe a 620 gal. tank. Thinking maybe just get the boiler now, re-line my masonry chimney with 6" ss. Pipe the tarm into my existing boiler with the HW sidearm and run it through the next winter. Next year get the storage.
Hoping it can replace 2 woodstoves provide me with plenty of hot water. and burn about the same amount of wood, about 5-6cords.
Thanks,

 

[Eric Johnson]

That sounds like a great plan to me, Chuck. Bear in mind that gasifiers need REALLY DRY WOOD. Cutting it now and expecting it to be dry enough to work well by next winter is probably wishful thinking. They work like a dream with the right wood, but it all goes to hell pretty quick if the wood isn't dry enough. And I'd plan on burning more than 5-6 cords, just in case.

There's no doubt in my mind that you'll be able to heat your house and hot water with no problem if your wood is dry enough.

 

[ISeeDeadBTUs]

Ok, I don't have storage, though I have been considering a buffer tank. But when I read some of the responses on this thread, I got concerned. Where the hell is NoFo when we need him?

Storage is NOT going to make you burn significantly less wood, especially during winter. Storage simply lets you burn flat out, eliminating idling. If you are not over-sized, idling should be minimal during winter already.

In theory, if you had a large enough and well enough insulated tank, you could burn once for the entire winter. But that one burn would be like 3 weeks long. Don't get too hung up thinking storage is going to heat your house without burning to heat the storage.

I'm no expert on this subject, but I think before you do anything, you need a heat loss calculation, then figure how many pounds (convert to gallons) of water you need to heat your place for the desired load cycle. Then don't forget to calculate how many hours you will have to burn to recharge the tank.

 

[Eric Johnson]

I think nofo snuck off and took a sabbatical--without checking with me first!

I think you do burn less wood with storage. Or, let me put it this way: I think I would burn less wood with storage. When I get a chance I'll explain my reasoning.

 

[chuck172]

I have about 6 cords tucked away for next winter. The people at Tarm told me without storage the solo40 might take more tending in the way of partial loads to prevent overheating and I might get more creosote due to idling. Definitely with storage the 40 would be fine. So for 600. more, it may be worth it. Still unsure, its allot of info to take in and a big investment.

 

[chuck172]

There really is allot to learn about wood boilers and gasification. I thought I might have it figured out thinking I would get the Tarm solo 30 with no storage for a year and then I'm wondering if I should go with the solo 40 for $600. more. Then ISeeDeadBTUs throws the heat loss calculations at me. The people at Tarm said it would be fine to get the solo 40 if I get storage in the future, I might just have to tend the boiler more this winter with possible less than full loads to avoid overheating.
Then I'm thinking maybe just biting the bullet and getting the storage tank and boiler together now but I'm just too cheap.
Eric, you made alot of sense with the dry wood. I have about 5-6 cords in the shed now but I'm thinking maybe split up some more now. I do have some trees down now that I could buck , split and stack.
And to think, I'm gonna have have all kinds of piping to figure out soon!
I don't know what I'd do with-out you guys on this forum. Real helpfull.

 

[Eric Johnson]

Relax. If you have wood drying in the shed, you've got all summer to figure out the piping and other details. We'll be around to help out.

 

[chuck172]

Brought a smile to my face, thanks Eric.

 

[bbb123]

Ok, I don't have storage, though I have been considering a buffer tank. But when I read some of the responses on this thread, I got concerned. Where the hell is NoFo when we need him?

Storage is NOT going to make you burn significantly less wood, especially during winter. Storage simply lets you burn flat out, eliminating idling. If you are not over-sized, idling should be minimal during winter already.

In theory, if you had a large enough and well enough insulated tank, you could burn once for the entire winter. But that one burn would be like 3 weeks long. Don't get too hung up thinking storage is going to heat your house without burning to heat the storage.

I'm no expert on this subject, but I think before you do anything, you need a heat loss calculation, then figure how many pounds (convert to gallons) of water you need to heat your place for the desired load cycle. Then don't forget to calculate how many hours you will have to burn to recharge the tank.

I agree I don't think storage is a huge wood saver (just a little). I do belive it is a huge ease of use for these boilers. Storage was sold to me to make it a 12 month system instead of 7 or 8. It does that and more once I figured it out (that 2 year learning curve thingy). Burning wood everyday is not an option for me in the summer we did that with an old Tarm when I was a kid. Once a week I can deal with still wish I put a solar HX in.

 

[chuck172]

Are you burning one full load once a week for hot water now? By the way, what is a solar HX?