Boiler Advice Needed for Newby

[gorsuchmill]

Given the high cost of heating oil I'm considering adding a wood boiler to supplement my oil system. I live in an older house that has average insulation and have been using approx. 1,000 - 1,200 gallons of oil each year for a water boiler that drives approx. 1/3 of the house with radiators and the remaining 2/3 using heat pumps with hydronic coil backups. My DHW is also boiler fed. My current boiler (Peerless 135k btu) is located in an unfinished first floor room that is below all other floors, kind of like a walk out basement. I have a separate flue from an old wood stove that I think would serve a wood boiler just fine.

I have access to fire wood on my property and an 8 year old employee (son), and am beginning to think a wood boiler would help me greatly reduce my oil needs. I've looked into a Biomax 40 ($6,500), Tarm Solo 30 ($6,300) and Wood Gun ($7000 for carbon steel) and was wondering if any of you have thoughts about these or other units I should look into. Also, the Tarm rep spec'd the 30, a smaller unit, with the mindset that it should handle my needs 95% of the time, with the oil boiler helping out on the coldest days. This seems to make sense in that it would be cheaper up front, but also allow me to "drive" the unit hard instead of having much less btu need than a larger boiler would produce. The next size Tarm Solo was $6900.

I don't plan to do storage immediately, but thought I would add it if I was using the system as much as I intend and could justify the cost at a later date.

Finally, I keep seeing install costs in the $12-$20,000 range for wood boilers, but the prices shown above are well below that. I suppose the install and supplemental storage could be the answer, but is it reasonable that I could have a system in place (without storage) for $7500-$8500?

Thanks, in advance for your help.

- Lee

 

[Eric Johnson]

Hi Lee. Welcome to the Boiler Room.

The other two gasification boilers of the type you mentioned would be the EKO and the Econoburn. There's a link with EKO prices (top banner) and a link to the Econoburn website (bottom banner).

If you plan to do the installation yourself, I'd allocate between $1,000 and $2,000 for parts and accesories, depending on a number of different variables. Some heating contractors won't touch solid fuel boilers, but there's nothing too exotic about the piping, so you don't really need specialist, I don't think. But you're probably on your own when it comes to the chimney hookup and setting up the boiler. But you can get all the advice you need on that right here.

Anyway, your plan sounds like a good one. If you plan to incorporate hot water storage at some point in the future, the sizing the boiler becomes less of an issue because the tank serves as a buffer between the boiler and your heating needs.

As to recommending a particular brand, I can only comment on what I own, which is an EKO. I've been very happy with it. Plenty of people around here with the other brands, so if you have any specific questions, I'm sure we'll be able to come up with an informed answer.

 

[Nofossil]

I started out without storage. It would be good to plan for it, but don't feel like you have to have it. Eric's probably about right. A lot of the cost depends on your scrounging abilities. Copper and boilers are both way up since I did mine, but I got the whole system including storage for around $7k.

I would agree with choosing the smallest boiler that can come reasonably close to meeting your needs. I bought an EKO 25, and I've ended up restricting the air inlet to reduce its output. You're exactly right about the benefit of being able to run it flat out for longer - especially if you don't have storage.

 

[Tony H]

I can only comment on the additional cost beyond the boiler as I purchased the items
pressure relief valve
Temp pressure unit
air scoop
expansion tank
ball valves
termovar mixing valve
pump
domestic water sidearm
domestic water mix valve
PEX pipe
pex fittings
Black iron or copper pipe and fittings

I can say I have over 2000.00 invested in these items

 

[gorsuchmill]

Thanks everyone for the input. I intend to do the storage, but want to make sure I'm as enamored with wood heat after I get my system up and running as I am now before I commit the extra funds to a storage unit. On the EKO, do you get much smoke when you feed the unit? My setup will be in a basement, for all intents and purposes, and I don't want to smoke myself out. One of the benefits of the Biomax, I'm told, is that it has a draft fan that pulls away from the door and thus emits less smoke during refueling. That said, the Tarm has a good reputation and many here speak highly of the EKO. I don't see much about the Biomax to know where it fits in with the others.

 

[Eric Johnson]

I've never seen a Biomax, but somebody told me that the guy who imports the EKO, Zenon Pawlowski of New Horizon Corp., designed the Biomax as an improved EKO. Which is hard to believe, given how well the EKO works, but it's good news if it's true.

I do get some smoke coming out of the firebox door when loading my EKO 60--sometimes more than others. Since it's in my barn, I don't really care or make much effort to figure out how to avoid it. You'll see that some people put exhaust hoods over their boilers to catch the smoke when loading. Pretty simple to do with an inline fan and a little sheet metal fab or modification. But I'm sure you could figure out a pretty good loading routine that would minimize the tramp smoke.

There's no smoke at all under normal operation--either coming out the chimney or the boiler itself. And if you load it like you're supposed to (I don't) with full loads after it's burned down to coals or from a cold startup, I suspect any smoke would be basically a non-issue.

 

[Nofossil]

I get virtually no smoke, but it took me a couple of years to get there.

The secret is to avoid the temptation to open the loading door until the fire has died down to mostly coals. When you've got high-volume gas generation going, it will puff at least a bit if you open the door.

So how do you tell?

1) Stick a thermocouple in the secondary chamber. 600 degrees or less, and you're good to go.

2) Listen for the 'gasification rumble'. No rumble, you're OK.

My pattern is to build a fire and fill the box with loosely stacked progressively larger wood up to near the top. I'l light it, and close the damper / secondary door after six minutes, and turn on the controller. Kicks right into secondary combustion. I'll come back in about an hour and fill it with densely stacked wood. It's then good for three or four hours, after which I'll fill it again only if it's pretty cold or the storage tank is really depleted.

 

[gorsuchmill]

Thanks. It looks like I've narrowed my options between the Tarm and Biomax units. Now I just need to decide whether to go for storage from the beginning or wait for a season or two to pass.

 

[sparky1961]

check out greenfirefurnaces it simular to a seton and greenwood and is not over priced.

 

[Jersey Bill]

I have been running without storage for 3 years. My boiler is sized tight so that if the outdoor temperature is below 22 or so, I can run it flat out. At about 5 the gas boiler has to fire periodically to maintain 140 in the loop. Its a great efficient burn, until I go to bed, then the gas boiler will come on. To keep the boiler at full output I would have to load wood every 2 hours. On cold nights I will get up 2 times, but thats my limit. If the outdoor temp is above 40, I cant fire the boiler unless my wife is doing a lot of laundry. Since the house heating load is small, the loop temperature rises too quickly and the boiler has to shut down before it gets to full output.

Running the wood boiler as much as possible, I have not been able to get my yearly gas consumption below about 35% of what it was without wood. If I add storage I can burn continously much further into milder climate and pick up the hot water load as well. In the summer I could fire the boiler on a laundry saturday heat up the storage, and pre-heat the domestic water for the week.

The catch here is that on the coldest day, I would still have to rely on gas when I am sleeping. Since the wood boiler matches load below 22, I would not be able to get ahead and charge the storage for the night. The answer for me is to get a bigger boiler, maybe 50% larger than the load so that even on a really cold day I can charge the storage.

SO, my comment in a nutshell, is that the boiler optimum size will be different depending on the size of the storage. My personal goal would be to get 6 hours of sleep on the coldest night. As far as the cost, look at the payback time.

 

[Eric Johnson]

I've got a big boiler with no storage and we burn zero gas, plus get 8-10-hour burns under most conditions. And that's in Central NYS, where it does get pretty cold. I think with storage it will be even better.

Probably the only downside is that my boiler does idle in warmer weather, and that eats wood and shortens the boiler life. Storage should minimize the idling.

Everybody has different conditions and experiences, as well as expectations, so it's hard to generalize, and I can only speak for the EKO, since that's the only gasifier I've ever used. Beats the pants off a conventional wood-fired boiler in every way, IME--and I've owned two of those over the past 15 years.