Need your help in choosing a wood boiler

[Firefighter Bob]

Greetings:

I have never owned / used a wood gasification boiler. I am looking for a boiler in the 100,000 - 130,000 BTU range. I have a 600 gal insulated stainless steel hot water storage tank. I will be burning seasoned Ponderosa pine.

My house is 3,200 SF and very well insulated with R-40 walls (lots of thermal mass), R-60 roof, low-e windows and in-floor radiant heating. For example, with overnight lows of 25 F last night, my house without any heat on was 65 this morning. We typically have winter overnight temps in the teens, sometimes negative, with daytime highs in the upper 30's - 40's. Last winter, my solar / propane boiler heating system typically came on about 3 hours a day, in the early morning.

Which makes and models of wood gasification boilers would you recommend and why? What are the pros and cons? I'm concerned about the quality of the boiler, the supplier standing behind the boiler warranty, available replacement parts, cost of parts that wear out (i.e., refractory liners, etc.), and of course, performance. Any help and recommendations that you can provide would be wonderful!! Thank you, Bob, Vol. Firefighter / EMT

 

[Singed Eyebrows]

Hi Bob; I'll put in my 2 cents worth for the Wood Gun. A stainless WG is not cheap, would probably be the last boiler you need to buy though. The quality is excellent, warrantee is not a problem on this boiler,USA made, Parts are a phone call away & probably shipped the same or next day(I wish I could say the same for my Atmos), a complete center nozzle brick set was $100 last time I checked, any part you need you can get. This will burn wood with 40 percent moisture although the efficiency is not good at this moisture content. This boiler will also power vent as per the factory posting on Hearth, you would want to check with WG before doing this though. Good luck, I have a feeling others will recommend different boilers,LOL, Randy

 

[Nofossil]

Welcome to the forum. I think you'll find that people are hesitant to say that any one boiler stands out. As far as I can tell, they're all pretty good. It sounds like you'd want a smaller unit, and in the end it may boil down to what you can find locally. Will you be doinf your own install? If not, the experience of local system designers and installers probably matters more than the brand of boiler.

There are a few distinctions that can be made, but most of them are personal preference: Domestic or foreign? Simple or sophisticated? In the end, I don't think there are any bad choices.

 

[flyingcow]

One question, seems like you have a well insulated house. Why spend $10 to $15,000++ on switching to wood? Seems you're heating costs should be fairly low? Just curious. More power to you, if it's what you want to do.

 

[Firefighter Bob]

Thank you for that suggestions so far.

Re: Signed Eyebrows; thank you, yes, I would love a good SS boiler, if I can afford it.

Re: Nofossil; thank you, we don't have anyone locally (Flagstaff, AZ, 7,000' elev) that installs wood boilers. I do know of 2 Tarms in town... a friend has had one for several years and likes it. I built my house (owner builder) and built and designed my radiant floor system, propane boiler system, solar system and hot water storage, so I will also be installing the wood boiler.

Re: Flying Cow; thank you, I would like to find a wood boiler in the $5,000 - $7000 range. I have 10 acres with about 6,000 trees... plenty of natural fuel.

 

[Como]

What size is your propane boiler?

 

[sgschwend]

Before you purchase a unit, try and talk to their service people. Are they in your time zone, do they speak the same language? Certainly any communication obstacle can be overcome but why not choose a USA source?

 

[Firefighter Bob]

Thank you for the suggestions:

Re: Durango; thank you, the propane boiler is 46,000 BTU. On a good solar day, with outside temps day 60's / night 30's, if my 600 gal storage tank is up to 115F, the boiler can heat the house with about 2 -3 gals of propane per day. On colder days (overcast day 30's / night 10), it has a hard time heating the house to 68F.

Re: Sgschwend; thank you for the suggestions.

------------------------------

I'm not really looking for people to badmouth any of the companies / boiler models, but I would love to hear your positive experiences with boilers you've owned / have had experience with... in other words, your recommendations.

 

[Hydronics]

Well here's my 2 cents since you asked for it:
The Tarm, EKO, Paxo, Econoburn, Woodgun and Garn are all high quality units. The Garn would not fit in your budget & it looks like you already have storage anyway. I had a well functioning updraft Buderus so I wasn't in a rush to get a gasifier, I literally researched them all for a couple years. They all have advantages and disadvantages.
I really wanted to buy American but couldn't justify the additional cost. Best to support our economy & be able to get parts locally, the Tarms & EKO's seem to have parts readily available here in the US though. I could buy 2 EKO's for the price of a comparable stainless Woodgun. In my opinion it's tough to beat the EKO (quality for the dollar) & their controller has the greatest capability and adjustability.
Again, only my opinion based upon thorough unbiased analysis. I think you'd be satisfied with any of these boilers though.

 

[Como]

Durango; thank you, the propane boiler is 46,000 BTU. On a good solar day, with outside temps day 60's / night 30's, if my 600 gal storage tank is up to 115F, the boiler can heat the house with about 2 -3 gals of propane per day. On colder days (overcast day 30's / night 10), it has a hard time heating the house to 68F.

I was trying to get a feel for how many burning days you have.

For 2 or 3 gallons of propane a day, it simply is not worth it.

So it is all down to the colder days, how many and the investment vs payback.

Asuming there are not a lot of very cold days then the installation and maintenance costs far out weigh any wood issues, and if it is just basically a top up on those days then being able to run for x days without firing is also not an issue. You would buy the smallest of whatever brand you go for, burn it hard and hot, get the tank up to to temperatue, the building up to to temperature, and if may well be a few days before you would need to top up again.

I take it that you have looked at adding more solar hot water panels? Just wondering if that was a better investmennt?

I have the opposite issue, I can not justify the expense for the few really cold days, but will be burning most of the year so ease of operation, efficiency, storage etc is a very big issue. We iwll just be not so warm for the really cold week.

 

[stee6043]

Durango; thank you, the propane boiler is 46,000 BTU. On a good solar day, with outside temps day 60's / night 30's, if my 600 gal storage tank is up to 115F, the boiler can heat the house with about 2 -3 gals of propane per day. On colder days (overcast day 30's / night 10), it has a hard time heating the house to 68F.

I was trying to get a feel for how many burning days you have.

For 2 or 3 gallons of propane a day, it simply is not worth it.

So it is all down to the colder days, how many and the investment vs payback.

Asuming there are not a lot of very cold days then the installation and maintenance costs far out weigh any wood issues, and if it is just basically a top up on those days then being able to run for x days without firing is also not an issue. You would buy the smallest of whatever brand you go for, burn it hard and hot, get the tank up to to temperatue, the building up to to temperature, and if may well be a few days before you would need to top up again.

I take it that you have looked at adding more solar hot water panels? Just wondering if that was a better investmennt?

I have the opposite issue, I can not justify the expense for the few really cold days, but will be burning most of the year so ease of operation, efficiency, storage etc is a very big issue. We iwll just be not so warm for the really cold week.

I was having the same thoughts here. It's one thing if you want to burn wood for the green/neat/enjoyment factor. But with the numbers you're running on propane I don't think you'll ever be able to cost justify this. You'll find a lot of great info on some great boilers on this site. But you might as well throw the payback argument out the window!

 

[sgschwend]

So how much saving a year does one need for it to be cost effective?

I ask because we have had that conversation in my house and were divided on the value. We agreed that we would save about $1000 per year.



Purchasing a used boiler and doing all of the install was the only cost effective way in my opinion, not fully shared here.

 

[sdrobertson]

So how much saving a year does one need for it to be cost effective?

I ask because we have had that conversation in my house and were divided on the value. We agreed that we would save about $1000 per year.
Purchasing a used boiler and doing all of the install was the only cost effective way in my opinion, not fully shared here.

It would depend on several things...length that you figure on staying in the same home, projected cost of system, and most importantly were you feel the fossil fuel prices are going to do in that length of time. Oil is back up to almost 80 a barrel and the world economy is still not that great. Some of the figuring if its worth it is having a good crystal ball....

 

[stee6043]

So how much saving a year does one need for it to be cost effective?

I ask because we have had that conversation in my house and were divided on the value. We agreed that we would save about $1000 per year.



Purchasing a used boiler and doing all of the install was the only cost effective way in my opinion, not fully shared here.

I'm saving between $2300-2700 per year with my wood boiler.....

 

[Firefighter Bob]

Thank you everyone for the comments and suggestions.

Re: Hydronics, thank you for the comments and insights on the various boilers... very helpful!

Re: Durango, thank you; the last few overnight lows (7,000' mountain elevation) have been in the 20's, with some 12's last week. We get about 20 feet of snow and the typical winter overnight lows are in the 20's - teens, but with some zero's and rare negatives. With as much snow as we get, more solar panels wont do the job. I could put in a larger propane boiler, but would rather take advantage of free fuel (wood) and keep my small propane boiler as a backup. Also, due to icy / snow steep roads, I would need to buy 500 gals. ($$$) of propane before winter sets in... hard if not impossible to get it delivered during winter. My thought is that I would start a fire at about 10 PM and have my programmable thermostats kick-in then to pre-heat the floors. Then as the boiler burns down, the remaining heat would dump into my storage tank.

> One other issue that I haven't mentioned (should have) is that I also have a 30 gal elect. water heater in the loop as well... so my monthly heating bill (propane and elect.) probably exceeds $400 x about 5 winter months = $2000. If I got a $5,500 boiler less the $1,500 tax credit and install and maintained it myself, I'm hopping to break even in a few years. Are my assumptions correct?

Re: Stee6043, thank you for the comments.

Re: Sgschwend, thank you for the comments.

Re: SRobertson, thank you for the comments. Yes, I'm very concerned with the ever rising cost of fuel and (sorry to get political), if "Cap and Trade" passes in the U.S. Congress, we're all going to see "DRAMATIC" energy cost increases!! I'm almost 53 years old, so we plan to stay, so I hope this is our last home.

 

[Gooserider]

Sounds like the economics of doing a boiler make sense... I suspect those that were wondering about it are used to the pictures we usually see of AZ being a hot desert that's way down south... I think a lot of us forget that it also has some cold mountain regions as well.

Certainly your numbers don't sound that different from any of our users up here in the Northeast...

The other advice you've gotten sounds pretty good to me, I don't have anything all that significant to add to it. You might find your storage a bit on the small side, but that can always be expanded later.

Gooserider

 

[Firefighter Bob]

Re: Gooserider, thank you for the comments and suggestions. It's nice to hear from everyone that I'm basically pointed in the right direction... and not at a cliff. Yes, it's nice here, low humidity and liveable temps... unlike Phoenix and the deserts, it's in the 80's during the summer and actually not that bad in the winter.... it was in the low 20's this morning and will hit the mid 60's this afternoon. We typically see a year-round daily 40+ swing in temps from day to night. Winter and snow typically doesn't really hit (stick) until after Jan. 1st.

If anyone is interested, I built my house out of Navajo FlexCrete (www.Flex-crete.com) which is a green building product, aerated concrete block made out of 60% fly-ash recycled from the coal-fired electrical plant located in Page, AZ. A solid 12" x 8" x 24" block (about 50 lbs) gives you a fireproof, almost soundproof R-40 wall. You build it just like CMU's (concrete blocks) with rebar and mortar. To top off the house, I used spray-in expanding foam on the underside of my attic roof, about 10" thick for an R-60+. Tight, comfortable house.

 

[Como]

Odd co-incidence, I am currently designing my Garn Barn and I was looking for a local ish supplier. I used this sort of product 30 years ago in extending a house but seems uncommon here.

Thanks for the link

My weather conditions are sort of similar, except that I am a fair bit higher and further north. The big temperature swings help out when it gets cold, you know it will not stay that way all winter.

 

[Firefighter Bob]

Re Durango, I originally was going to use E-Crete, about the same price as Flex-Crete. The shipping from AZ might be expensive. There are some companies making AAC (Aerated Autoclave block) on the East Coast. I like the Flex-Crete better than the E-Crete... winters much better without any finish. The Flex-Crete website describes a mortar-less construction where you simply stack (no masons) the blocks and use compression (cable / threaded rod) to tighten them down to form the structure. Unlike CMU's, I can screw drywall screws directly into the blocks for attaching wood and drywall, although it's a bit soft. Amazing thermal mass... heat, cold, humidity does not pass through the walls... like living in a thermos bottle.

 

[Firefighter Bob]

Update: I just ordered an EKO 40 with a draft inducer... can't wait for it to arrive! As some of you had said, Zenon was very nice and helpful.

Once again, thanks to everyone who gave me feedback and suggestions... they were all extremely helpful and appreciated!!

 

[Como]

Makes you wonder why AAC are not more comon. I am used to being able to get them in any Home Depot equivalent. E Crete have a distributor listed in Colorado, for the amount I need a road trip could be in order.

Congratulatons on your purchase.

 

[Firefighter Bob]

Thanks Durango. My house and garage is about 4,000 sf, with mostly 10' and 11.5' (garage) high walls. The cost of the Flex-crete was about $15,000 with $1,500 delivery for 3 flatbed semi deliveries from Page, AZ, about 140 miles one way. The mason cost $7,500 to build the exterior walls in 8 days. What's so neat about the block is: no insulation, no studs, no house wrap, and no exterior finish for 2 winters and no furring strips behind the drywall... 3" screws directly into the block. Also, you can cut it with powered and non-powered wood working hand tools... a 16 or 18 inch bandsaw would be the perfect tool for the entire job. BT

 

[jjhpf]

Bob

Your in a great part of AZ - one of my sons lives in Clendale, we have been visiting the past the past 4 years. Have done the Whiskey 50 two times.

I have a Tarm Solo 40 - brand new never fired that I am selling to pay off my third sons out of net work medical bill. Never has had a fire built in it. The two friends of yours who have a Tarm can speek for quality of stove I'm sure. Price is 6,500 - compared to 8,500 for new. Talked to local stove dealing and he said it would qualify for the 1500 tax rebate.

If interested call 5177640999-h 5172422147-c

jim

 

[ISeeDeadBTUs]

I have a 'refractory mass' boiler. These style are commonly packaged under GeenFire, Seton, GreenWood, etc. I am thinking that if you will definitly have storage, these are NOT the style for you. These style are naturally aspirated and will probably not give you the efficiency of a forced induction downdraft when combined with storage.

I think you may be dreaming when it comes to how much you want to spend.

 

[Firefighter Bob]

Hi Iseedeadbtus: Great user name! Thank you for the comments. I just bought a EKO 40 gasifi (should be here next week) and was able to get the summer sale pricing... delivered for about $5700. I have an insulated 600 gal SS hot water storage tank. My house is so well insulated that this morning with 18 degree temps, my 46,000 btu propane boiler was able to keep us warm (68) for under 3 gals of propane. The new boiler is 90,000+ btu larger... can't wait to get it. BT