running a boiler without storage

[tjvt]

I think I understand the major benefits of storage, but our budget and lack of space say not happening. It's my understanding that storage will cut down creosote buildup by allowing the boiler to burn wide open, and provide a place to dump excess heat for later use.

I'm very interested to hear how those of you without storage are making it work. How do you deal with the shoulder seasons? Is your boiler idling excessively, and are you worried about the resultant creosote shortening the life of your boiler? Can you just load less wood, and let the smaller load burn hot? What happens in the morning, presumably nearing the end of a burn cycle (assuming you loaded the boiler around bedtime), when you need hot water? Since there is no heat reserve in storage, is your backup DHW system having to carry the load at these times? What percentage of wood might I save with storage vs. without? Any other challenges unique to systems w/o storage that I should be aware of?

Thank you,
Tyler

 

[hobbyheater]

I think I understand the major benefits of storage, but our budget and lack of space say not happening.
How do you deal with the shoulder seasons? What percentage of wood might I save with storage vs. without?
Thank you,
Tyler

Lack of space and budget set of warning bells!
Shoulder seasons don,t burn wood!
Storage for me reduced wood consumption by 40%.
There are so many different boilers on the market each one is going to react differently to varying periods of idling, so you will have to be more specific as to which boiler you are going to use .
Your wood is going to have to be extremely dry!
I would suggest a pellet boiler!

 

[mike van]

Save your money then until you can do the complete job the right way, one time. Once you go past a simple woodstove / fireplace, all systems are expensive. Don't run without storage, it defeats the purpose. I ran a Harman add on woodboiler for 16 years with no storage, mostly because I didn't know better. I have the unofficial record here for non reported chimney fires. Don't do it.

 

[maple1]

Do you have a wood boiler now? What is it? If not, what are you planning to get?

Here's a scenario - someone has an old non-gassing boiler, but it has fire tubes so has fairly decent heat transfer even if it is a dirty burner. IMO he would be better off or see a better return on his work/investment by adding storage to his old boiler, as opposed to going to a gassifier with no storage. Storage doesn't have to be expensive - generally speaking, I'd estimate the storage component at maybe 1/4 the cost of a new boiler. Depending on the boiler, and local situation for finding storage tanks, of course. But storage alone would make a huge impact on the operational efficiency of an older boiler - again, as long as the boiler has good heat transfer efficiency. But if you've got an inefficient old unit like my old one was, storage won't do anything for it.

 

[tjvt]

I'm pretty much narrowed down to Tarm Solo Plus 40, Vigas 40, or Garn Jr.

 

[infinitymike]

Well than go with the Garn Jr and you won't have to worry. It has storage built right in.

 

[tjvt]

Well than go with the Garn Jr and you won't have to worry. It has storage built right in.

Right, but back to the cost issue. I have a lead on a 2 yr old, never fired SP40 for $6500. The Garn Jr. will run me twice that.

 

[maple1]

Right, but back to the cost issue. I have a lead on a 2 yr old, never fired SP40 for $6500. The Garn Jr. will run me twice that.

He likely wouldn't have recommended the Garn if you hadn't said it was on your short list - which then implies it's within your budget.

EDIT: And, if the Garn Jr. is on your short list, that's almost implying that you'd have room for some storage too. They're kind of big.

 

[peakbagger]

I got my Burnham boiler for free and tried to run it for several years without storage. It was frustrating and I ultimately switched back to running a wood stove for shoulder seasons and the wood boiler during real cold conditions or when I had gone for the weekend and had the thermostat low. My oil usage was still 1 to 2 hundred gallons per year. I tended to overheat the house frequently.. Once I put in storage my oil usage went to close to zero and overheating was quite rare. IMHO, I would probably stick with a good woodstove until I could afford storage for boiler. There is a reason why most boiler companies do not recommend operating gasifier type boilers without storage.

 

[tjvt]

He likely wouldn't have recommended the Garn if you hadn't said it was on your short list - which then implies it's within your budget.

EDIT: And, if the Garn Jr. is on your short list, that's almost implying that you'd have room for some storage too. They're kind of big.

I was under the impression that the footprint of an SP 40 or Vigas 40 with 1000 gallons of storage was significantly larger than the footprint of a Garn Jr.

 

[maple1]

What's your heat load? How big a boiler do you need?

 

[tjvt]

I don't know how to calculate heat load, but the dealers I've spoken with have recommended these sizes based on our situation. We're heating about 3200 sq ft, hwbb and radiant slab. Right now we burn 6 cords of wood in a wood stove on top of 1000 gallons LP (140k btu Munchkin). The Vigas dealer did recommend a 60 if I went without storage.

 

[maple1]

I'm just posting this one just to give some perspective on the footprint size thing - not saying by any means either way is better than the other.

From the Garn Jr. specs, it has a footprint of 38.2 sq.ft. (67.25 x 83.25).

I have a Varm UB 40, and 660 gallons of storage with two stacked 330's. The boiler specs are 24.8" x 33.7", and the tanks are 30" dia. x 9' long. So call their footprint 3' x 10'. Adding all that footprint space up comes to around 36 sq.ft.. I have another 110 gallon tank on end for expansion, call that one another 5 sq.ft. - but it's under the stairs where nothing else would go.

Of course, you have other stuff that takes up space but is kind of hard to measure - like smoke pipe, and some water piping. But storage doesn't have to take up a whole pile of space - or be way expensive. Propane tanks can be had in different sizes & put together in different configurations to fit in a lot of different spaces. Modularity. If you can get them vertical, that's even less footprint. Sourcing them might be an issue depending on local situation - I thought I was behind an 8-ball until I found a mountain of them at a large scrap metal place an hour away.

 

[goosegunner]

I don't know how to calculate heat load, but the dealers I've spoken with have recommended these sizes based on our situation. We're heating about 3200 sq ft, hwbb and radiant slab. Right now we burn 6 cords of wood in a wood stove on top of 1000 gallons LP (140k btu Munchkin). The Vigas dealer did recommend a 60 if I went without storage.

Bigger boiler because you don't have storage is a bad idea if he is suggesting that for longer burn times due to the bigger firebox.

I ran my Econoburn 200 for the 1st year without storage. It can be done but it takes a lot of attention if you want to keep the boiler running some what well. If someone is around during the day it is best to just put in a few pieces multiple times a day. You will still get a lot of creosote build up. The difference in convenience and boiler condition when running storage is amazing, I would not want to go back.

Initially the Garn might cost twice as much but I would predict that you will not be real happy running without storage. At some point you will probably want to up grade your system. Once you buy tank, loading valve, expansion tank, crap load of large valves, fittings and pipe, no power dump set up and other miscellaneous parts the price gap will narrow greatly or even make the Garn cheaper. That does not even factor in how much easier it is to install the Garn.

gg

 

[maple1]

Yes, kind of curious on the reasoning of a bigger boiler for no storage. I would think that would lead to increased creosote production & maintenance from increased periods of idling - and increased amounts of fuel in the box while it was idling.

 

[hobbyheater]

I'm pretty much narrowed down to, or Garn Jr.

You could not go wrong with a Garn Jr. a very good choice!

 

[tjvt]

Shifting gears here, but how efficient are the outdoor gassers? Portage and Main is starting to look good to me. By the time I buy a decent indoor boiler, install it, and add a boiler room to my garage, I will have spent appreciably more than I would on an entire outdoor setup. There doesn't seem to be a lot of support for the OWB's around here, but are the newer ones not smoke puking wood hogs as the dealers will have you believe? I had originally decided on an OWB, then got diverted as I thought I could save a lot of money and significantly reduce wood consumption with an indoor vs. outdoor. I'm no longer so sure. I plan to attend a forestry show here in VT on Sat to see one of these P&M's in action. They will supposedly burn higher moisture content wood and not smoke. Sounds too good to be true, but I'm intrigued.

 

[hobbyheater]

Portage and Main is They will supposedly burn higher moisture content wood and not smoke. Sounds too good to be true, but I'm intrigued.

Water does not burn !To good to be true!

 

[peakbagger]

OWBs have the same issues with part load operation and as they tend to be larger their issues are even multiplied. If a large boiler is asked to run at a low output its going to smoke and create creosote as the no matter what fancy catalyst is used the flame temp is going to be low. Older style OWBs dealt with this by just choking off the air and cranking out creosote, newer ones have hidden secondary air ports so they cant be turned down so they overheat the house that is connected to it. Burning high moisture equal lower flame temp and more pollution, that is physics. Unless they physically remove the fuel out of the firebox its going to pollute. What they can show you is steady state testing where the boiler is running full out, any boiler can be made to run pretty clean at full output but the reality is that few folks want the full output of the boiler 24/7 .

Before you buy anything check with Vermont air divisions website (broken link removed to http://www.vtwoodsmoke.org/index.html)

 

[tjvt]

I realize I can't cut a tree, buck it up, and throw it in the boiler. I also realize that I'm sacrificing efficiency by not burning optimal moisture content wood. What I would like, if one exists, is a unit that is more tolerant of wood that has, say, 5-10% "too much" moisture. A unit that will burn this higher MC wood w/o smoking out the neighborhood. Maybe this unit does not exist, but if it does I'm determined to sniff it out.

 

[maple1]

Have you checked out Wood Gun?

 

[tjvt]

Just checked out Wood Gun today. My list has grown to include Wood Gun and Portage and Main. Very interested to hear some objective input comparing an efficient gasifying OWB (P&M?) and an efficient gasifying IWB. What's the story with refractory mass and a boiler's ability to burn wetter wood? I heard the same thing from P&M and Wood Gun...higher refractory mass=increased ability to burn wetter wood. Truth or blowing smoke?

 

[Tennman]

Oh boy... this is gonna be interesting.

 

[hobbyheater]

Just checked out Wood Gun today. My list has grown to include Wood Gun and Portage and Main. Very interested to hear some objective input comparing an efficient gasifying OWB (P&M?) and an efficient gasifying IWB. What's the story with refractory mass and a boiler's ability to burn wetter wood? I heard the same thing from P&M and Wood Gun...higher refractory mass=increased ability to burn wetter wood. Truth or blowing smoke?

Look around for a used Jetstream it will burn wood with a 40% moisture content without smoking! Oops but it needs storage!

 

[Tennman]

tj, Four seasons of running without storage. I did the install myself to get us off propane and keep the house warmer. Which by the second season after a learning season and getting most of the kinks out, yes our home is much warmer. What you've read/learned... takes more attention, less efficient, far more idling, some creosote, etc. all true. But at the end of the day my non-storage system kept my home warmer and I'd guess by the end of the second season I had payback vs burning propane. Any regrets... nope. Happy with my "cost effective" gasser?... yep. Will storage make it better?... absolutely. Hoped to have had my storage online last Nov, but other life priorities bumped that goal. I didn't sit around worrying about firing up my non-storage boiler to keep our home warm last winter when it was brutal. My wife kept telling everyone, "Thank heavens for the BioMass! Our home's never been warmer." Over the years I've seen a crap load of creosote in our boiler and it clogs up the damper, but I fail to see it hurting the boiler. Absolutely agree with all that storage is better, but at least for us, burning non-storage is a heck of a lot better than the cash flow drain and colder house burning propane. This season since it was so cold I saw first hand how happy the boiler was working hard with little idling since it was so cold many times. I wished I had my tanks hooked up but they weren't so we just enjoyed non-storage heat that takes some more time to babysit. I've read your choices above and looks like you have good taste in boilers. Lots of happy owners of those, especially Garns, but also BioMass. My point, nothing wrong with doing things in stages to get to a goal of storage someday and save a ton of bucks staying warm in the meantime. Great bunch of guys, you're at the right place.