Where to start

[jasonh]

I have a couple lines on a few used boilers. A biomass 40 with 250 gallon storage, an economizer idm 100 and an econoburn 150 no storage to heat my house and dhw at 0* design temp. 0* design temp only because of the last couple winters we have been having. Not sure where to start in designing this system.

My house is 1850 sf Tri level with gas boiler and baseboards. The boiler is a Utica 100k, 83% efficient. There's 12 inches of batt insulation in the attics and all the exterior walls were foamed this last march. Windows are about 20 yrs old double paned.

I've been reading on here alot in the last couple years but never really found a good post or thread that said where to start designing besides heat load calculation. I've done quick ones recently but plan on doing a more detailed calculation this weekend.

So besides a heat load calculation, what's next? Then after that? I only want to install this once, besides maybe a boiler change, so I want to get this right.

Thanks. Sorry for the rambling.

 

[NateB]

The bio mass 40 should fit well, but 250 gal is much to small. The question for you is where are you going to place the boiler? Do you have a chimney there? Do you have an easy way to get wood to the boiler? Where will you keep the storage? What will the plumbing look like based on where you put the storage and boiler?

For plumbing I went with primary secondary, and I have a pump on each zone. There is a good sticky on here about primary secondary

 

[jasonh]

The 250 is what is being sold with the boiler along with the chimney. I've read guys use an eko w/o storage and it works ok. I plan on trying to find another 500 or 250 to go along with it.

Yes I have a jd 316 with a loader and rear forks. Plus I have boxes (4) that I got specifically for moving wood to use with my rear forks.

The boiler and storage will be in the corner of my garage approximately 90' from the south wall of my house. It's detached. I will quarter it off with some walls to keep everyone happy. I'll check out the sticky tomorrow. Thanks

 

[maple1]

If your current baseboard system heats your house OK, I wouldn't bother with the heat load calc. That comes more into play for sizing your distribution system, I found anyway. Either the Biomass or Econoburn will work, I don't know anything about the Economizer. So you 'just' have to pick a boiler & hook it up.

(EDIT: You can also always add more baseboard later, if you want...)

 

[stee6043]

What's next? Figure out your budget and figure out how much you hope/plan to save with the new boiler setup. From a purely fiscal point of view you may find that your money will be better spent on some additional insulation in the attic (blow-in) and new windows.

If you land on a boiler being the right decision for you I'd then suggest you figure out how you want to use it. The storage vs no storage argument is based largely on convenience (and most will agree with the post above that 250 gallons will not be enough to provide convenience). If you want to be away from the boiler/system for extended periods you'll want to strongly consider thermal storage. If you have a schedule that supports feeding a gaser a few times a day thermal storage becomes much less critical.

Good luck and welcome!

 

[DaveBP]

If you have kept all your records of gas usage (or your supplier might have them) you can convert that to a very practical heat load calculation. Might even be more realistic than a theoretical spreadsheet figure.

 

[jasonh]

My system works fine as is now. However I was also burning wood in my wood stove so my numbers could be off a little. I talked to dean from smokelessheat and we figured a 500 gallon would be sufficient.

Now being 90' from the house would 1" underground pipe be sufficient or should I bump it up?

What about pumps? I read people talking different head pressures and pump sizes. Would a taco 007 be enough or jump into a Laddomat and have some boiler protection .

 

[stee6043]

My system works fine as is now. However I was also burning wood in my wood stove so my numbers could be off a little. I talked to dean from smokelessheat and we figured a 500 gallon would be sufficient.

Now being 90' from the house would 1" underground pipe be sufficient or should I bump it up?

What about pumps? I read people talking different head pressures and pump sizes. Would a taco 007 be enough or jump into a Laddomat and have some boiler protection .

Can you share the details of your discussion regarding the 500 gallons? For what it's worth below are some figures you might want to consider:

Storage max temp - let's say 180 degrees (it can be hard to push beyond 180 for most of us)
Emitter min useable temp - my min is 140 for forced air (yours will be lower if using baseboard but your recovery time will also be longer. So I'd argue the overall storage strategy will be quite similar)
Effective useable heat in 500 gallons is 166,000 btu
Effective useable heat in 1,000 gallons is 332,000 btu

I'd wager a guess your house is in the 20,000 btu/hr ballpark average, maybe 50,000 btu/hr design load.

Based on the above on an average day 500 gallons will give you 8 hours of run time from storage. 1,000 gallons will give you 16 hours. The reason you'll hear most people say "anything less than 1,000 gallons is a waste" is because most of us in northern states can't go to sleep/work or leave the house for a meaningful amount of time with less than 1,000 gallons based on average heat loads for those of us living in average homes with average construction.

Perhaps 8 hours is good enough for some. Hopefully it is for you! With regards to PEX, 1" will not be enough to properly move heat away from a 40KW boiler. I think most folks around here find double 1" runs are more cost effective than increasing the size of the PEX.

 

[jasonh]

Stee I'd love to have double stacked 500's! However finding them can be an issue.

Regarding my conversation with Dean, I took what we had used from Dominion's website and the 3 cords of cherry I burned at the time he figured 500 gallon would probably be enough for 12 hrs. I believe 50k was close to what I figured before for my heat load.

I forget what the guys name was on here, but he had a varm 37 and 500 gallons that stack heating put in for him and he had 2 burns a day. Now his house is newer than mine but he lives about 50 miles north of me.

Gary switzer quoted me his 1050 gallon boiler would be fired once a day and his 550 gallon boiler would be fired twice a day. From his online calculator.

As far as the pex, your saying 4-1" lines is better? I'm assuming that's 1 supply and 1 return for the heating and 1 supply and return for the dhw. Would that require a seperate pump for the dhw? Now I'm getting confused.

 

[maple1]

I don't think he meant one for DHW & one for heating, rather T or manifold them together at each end so they run parallel for the heating system, 2 coming & 2 going. I would do that, or use one 1-1/4" line. (Well, two - one coming & one going). 1" is pretty restrictive over that distance.

I have 660 gallons (would like to have more but it's adequate), and last winter only burned 6 hours a day. There are other ways to help get more time between burns. I light up in late afternoon. An hour later my zones are all heating the house, around suppertime. The stats are set to 21c. They set back around midnight a couple degrees & stay set back until suppertime the next day. This gets more coasting time from storage, and I am burning when my heat load is the max. Part of that is I am usually the only one home during the day, so I don't need the whole house completely up to temp. So I basically am using the house for some storage too by heating it all up a bit warmer in the evening. Fire is out by the time I am going to bed.

Minumum storage size is based more on the heat output of a boiler full of wood, than anything else. Which is likely where the 500 figure came from. Beyond that, it comes down to how long you want to go before having to burn again.

And on another comment above, you want boiler protection no matter what - either via a Laddomat or other loading unit, or a Danfoss type of mixer that uses a separate pump.

 

[jasonh]

Well let me ask this question to the panel. Would an eko 40 be able to output enough heat 1000 gallons of storage with only 1 full load of wood? The reason I ask is say the tank(s) are down 75% could 1 load recharge it or would it take multiple loads? I wont have time to sit and keep loading the boiler. Unless it could last until the evening.

 

[NateB]

I have an 820 gal, which was sized for an eko 40, but I am in the process of hooking it up, so I have no real world experience yet. I hope to over the next few weeks.

 

[velvetfoot]

I wonder if the wood stove could be used in addition to storage? Especially if it provided ambiance and coziness near it. If you have a certain amount of hours of heat in the bank in the tank, leaving the house with a fire in the stove would stave off any heat withdrawal from the tank for a while.

 

[maple1]

Well let me ask this question to the panel. Would an eko 40 be able to output enough heat 1000 gallons of storage with only 1 full load of wood? The reason I ask is say the tank(s) are down 75% could 1 load recharge it or would it take multiple loads? I wont have time to sit and keep loading the boiler. Unless it could last until the evening.

One full load of wood should get you a half day of heat. So you could get a load going in the morning and it should keep the house nice & warm until you get home - then you could do another load at night. I do it different, I burn a load then a re-load later in the day and it does me till same time next day. But my burn aligns with my highest demand for heat from my house, which gets me more time between burns. Also it doesn't take time to sit & keep loading the boiler - get it going & load up, then either come back in 4 hours & reload on coals or come back half a day (or whatever your schedule dictates) later & relight another load.

That's one of the beauties of storage, it adds flexibility.

(I would guess that you could recharge 1000 gallons on one load of wood, if all or almost all the heat was going to storage).

 

[velvetfoot]

if all or almost all the heat was going to storage

That's a big 'if' though in the middle of the winter.

 

[jasonh]

Well I also found a 2 year old eko 80 for about the same price as the biomass 40. I'm sure the 80 would have no problem heating 1k of storage.

 

[maple1]

That's a big 'if' though in the middle of the winter.

Very true.

It would also depend on what one considers 'charged'. I don't try to heat my storage up as high as I used to. It takes more wood to raise it that last 10° than it does the first 10°. So very seldom sees much more than 180 now, at the top.

 

[velvetfoot]

So very seldom sees much more than 180 now, at the top.

Just curious. Does your tank setup stratify when charging, or is it more homogeneous at first and then settles out when the pump stops?

 

[maple1]

Well I also found a 2 year old eko 80 for about the same price as the biomass 40. I'm sure the 80 would have no problem heating 1k of storage.

You are likely very correct - 1000 gallons might be on the small side then. But should be very manageable by sizing your wood loads to storage temps. Would up the versatility & scheduling flexibility for sure.

Once you get into boilers that big (well, actually all of them), you want to make sure you have a very good overheat protection circuit or heat dump loop. If the power should happen to go out after you leave with a good fire burning, things can get dangerous in a hurry.

 

[jasonh]

You are likely very correct - 1000 gallons might be on the small side then. But should be very manageable by sizing your wood loads to storage temps. Would up the versatility & scheduling flexibility for sure.

Once you get into boilers that big (well, actually all of them), you want to make sure you have a very good overheat protection circuit or heat dump loop. If the power should happen to go out after you leave with a good fire burning, things can get dangerous in a hurry.

That's what I was thinking maple. Load what would be needed to charge the tanks to "180". Of course that would take some trial and error.
I have some other plans that may happen in the future so I'm starting to think maybe over size the boiler some, well alot with the 80, and then if I can build what I want it should be at the right size. If that makes any sense.

Would 2000 gallons be the "right size" for an 80?

 

[maple1]

Just curious. Does your tank setup stratify when charging, or is it more homogeneous at first and then settles out when the pump stops?

It stratifies very well, both when charging and when drawing.

Swapping in the Alpha pump on the load side helped a lot with that - I have the ball valves at each of my zone valves throttled down some so flow through there is fairly low. That is helped by the way my zones were laid out - rooms where more heat is appreciated are the first ones on all my zones. (Plus the normal occupants of the last two bedrooms on one of the zones are now at away at college). Would be even better if I had radiant heat. Not sure what my dT is thru the zones, but I rountinely see 30° difference in my tank temps when drawing - each measured in the centre of my 2 horizontal tanks (3'+/- of horizontal separation between the temps). This morning when I got up it was 160 top & 130 bottom, I didn't burn yesterday & not sure I will today yet as the sun is shining.

When charging it is very noticeable. The first lap through storage has 160 going in at the top, and whatever they have cooled to at the bottom. Usually in the 120 range. So the temps start out at about 130/120, and they stay that way until the top temp suddenly increases to 160 or so, then the bottom temps stays at 120-125 for a while longer until suddenly rising to 160 or so. Then more burning has the top temp upping to the 180 range with a delay again before the bottom temp starts rising. But not as much of a delay as for the first lap temp jump. I am usually letting the fire die by that point. Boiler flow through storage is quite slow for the first lap, as a lot of the water coming into the bottom of the boiler is going thru the bypass loop, since the water coming into the loading unit from the bottom of storage is only 120 or so. Plus I am also usually sending quite a bit of heat to the house during the first lap.

Also noticed that that can create an odd situation at times if all my zones are calling for heat when I am starting a burn & storage is cold - the zones are pulling in more than the boiler is putting out for a while, so they are also pulling in some cold from top of storage. Which means they are putting in some warm return water to the bottom of storage. So if both my house and storage have gone cold, the storage is charging backwards (from bottom up) for a while until a zone or two get satisfied. That can get real weird when you notice that your storage is stone cold, but your boiler inlet temp is more than its usual 140. Took me a few minutes to figure out how that could be.

 

[maple1]

Would 2000 gallons be the "right size" for an 80?

Not sure. If I had an 80, I would likely be OK having 1000 with it. But would appreciate more. I think a bare minimum for a 40 class boiler is 500, so that could be extrapolated maybe to an 80 should have 1000. At that point it would likely come down to how much you can fit into the space you have for it, and availability of tanks where you are. An 80 with 2000 gallons would be pretty kick-butt on the versatility side of things - but you would need to insulate everything very well, as the more storage you have the more potential there is for heat loss. Where the tanks end up also plays a part - e.g., heat lost from them isn't quite as big a deal if it is lost to a heated space inside your house. I also think I have concluded that the most important part of the insulation aspect in the install is under the tanks. It's easy to insulate around afterwards, but pretty hard to insulate under later. I didn't pay as much attention to that as I likely should have. I was able to wedge about 3" of foamboard under, and cram in bits of fiberglass & cellulose in other odd spaces, but think I am still losing a bit into the ground thru my basement floor. Heat lost to the ground is heat lost, no matter if the tanks are in your house or not.

 

[jasonh]

Not sure. If I had an 80, I would likely be OK having 1000 with it. But would appreciate more. I think a bare minimum for a 40 class boiler is 500, so that could be extrapolated maybe to an 80 should have 1000. At that point it would likely come down to how much you can fit into the space you have for it, and availability of tanks where you are. An 80 with 2000 gallons would be pretty kick-butt on the versatility side of things - but you would need to insulate everything very well, as the more storage you have the more potential there is for heat loss. Where the tanks end up also plays a part - e.g., heat lost from them isn't quite as big a deal if it is lost to a heated space inside your house. I also think I have concluded that the most important part of the insulation aspect in the install is under the tanks. It's easy to insulate around afterwards, but pretty hard to insulate under later. I didn't pay as much attention to that as I likely should have. I was able to wedge about 3" of foamboard under, and cram in bits of fiberglass & cellulose in other odd spaces, but think I am still losing a bit into the ground thru my basement floor. Heat lost to the ground is heat lost, no matter if the tanks are in your house or not.

I was just curious is 2k was a little on the extreme side. But if 1k is the minimum then 2k would be more than ideal. But your right heat loss will happen no matter what. Kinda like the angel's share in distilling whiskey and bourbon. For me my tanks would not be in the house at all but in my garage for now or maybe in my future shop. Same goes for the boiler.

I'm just trying to get an idea of what would suffice for now but still be ideal for future plans. I may take a closer look at the 80.

 

[BoiledOver]

I would say follow up on your heat load calcs, first. Similar to getting in the boat first before rowing. You stated in another thread that you know what you spent on NG so get those monthly statements out and see what your heat load has been for the past couple years.

The Eko 80 would be a sweet rig if you have enough demand or large enough storage. How many byus an 80 will produce in one firebox load is something you would want to know too.

Propane tanks are available in most rural areas but are not an advertised item. Talk with a propane supplier and ask where they get their reconditioned tanks. The outfit that does the reconditioning will have hundreds in all sizes sitting in his/her yard and will part with those that don't meet specs at close to scrap price. All it takes is a little ambition to locate and purchase used tanks for a few hundred dollars a piece.

The insulation and partitioning for the tanks will take up another 14 to 22 square feet of floor spacr, whether single or stacked. Add that to the roughly 35 square feet of the tank itself and determine if you want to sacrifice that much. 5'x10' is pretty close estimate. The boiler itself will require maybe 8'x8' for clearances and door swing. Flue requirements, zone board and room for some firewood too. You can lose a lot of real estate from your garage rather quickly. Mark a spot on your garage floor 12'x16' and ya might get everything into that (one stall gone). Do you have 10' ceiling in your garage for stacking tanks? My 9' barely made it.

Another thing, if you open the secondary door during its burning cycle, expect everything inside the (now a boiler building) to be covered with fly ash. Spring cleaning involves fans, brooms, a compressor and a respirator. It's tough to resist a peak at that blue flame in the first year. And of course everything will smell of smoke. Insurance issues no matter where it is placed or which model.

If you are still inclined to move ahead, you will scour this site some more to determine how many zones, circs, valves, bleeders, eliminators, control wiring, outdoor reset, pressure gauges, temp gauges, more valves, thermostatic valve and such. I know it sounds like I am speaking hardware but the truth being, it is $$$$$. How many years does it take to break even against NG costs? Still set on going with a gasifying wood fired boiler?

Continue to go over all the threads that have already been hashed out concerning a complete installation. It's all here from start to finish, if you make the effort, you will find it. If you are looking for someone to give you (for free) a complete evaluation and the plans like the pros get paid very well for, not so likely. This is a very helpful site with way more free information than you will need to complete your installation.

Use it with respect and stay warm.

 

[maple1]

Another thing, if you open the secondary door during its burning cycle, expect everything inside the (now a boiler building) to be covered with fly ash. Spring cleaning involves fans, brooms, a compressor and a respirator. It's tough to resist a peak at that blue flame in the first year. And of course everything will smell of smoke. Insurance issues no matter where it is placed or which model.

That's not universally applicable to all boilers.