Question for EKO and HS Tarm Owners

[boiler_interest]

Hello gang,

New to Hearth.com and quite interested in the "Boiler Room" area... I'm in the process of building a new house and winter is quickly setteling in! It's time to choose the means to heating this structure. I have my sites set on an outdoor located boiler, but have no interest in the water surrounded bond fire models I can appriciate the gasifier models! I was going to build a small stucture to house the boiler not too far from the house put a couple of 200 gal oil tanks as storage in the house basemement for this year until next summer where I will build an outdoor underground bigger tank. My back up heat will be a couple of 60 gal hot water tanks so I want to try to not rely on the electricity as much as possible. I've narrowed my search to eiter HS Tarm or Orlan, the EKO being about $2000 cheaper and the local rep being closer to here, for these reasons I'm leaning towards the Orlan at this time. I'm at the point where I have to choose the size of the boiler. The house is an 1700 sqr foot R-30 through out (ICF foundation and SIP panels walls) with full basement with radiant for heat and forced air hot water air handler for ground floor. There is quite a bit of glass area in the house not too much southern exposure and a cathedral ceiling in the living room. There is an 800 sqr foot garage attached that is insulated to the same R-30 that will be heated by radiant probably not to the full room temp but maintain a comfortable temp. Future would be a 1200 sqr foot work shop heated by radiant to probably 10 ° C except when occupied on weekends where it would be brought up to room temp. I hope to also do domestic hot water and in the summer cool times heat an above ground insulated liner swimming pool to 27 ° C. Given these specs does anybody have any recommendation as to what size Orlan 40 or 60 or HS Tarm 40 or 60. My Goal would be to eventualy go to one fire a day preferably starting the cycle after work and one feeding before heading to bed.

Could some of you owners give me an idea of home sizes being heated, insulation rating or age of home to give idea of heating loads. If your using storage, how big it is and how long you can run on stored heat?

Thanks in advance!

Paul

 

[hkobus]

Welcome to the site Paul,

I am running a Orlan 40 for the past month or so. The house I'm heating is about 140 years old and a little shy on R-value. At this time I don't have storage yet, but the plans are getting to the point where I will build in the next few weeks.
The main reason is that the unit idles a lot right now with the mild temps and it uses a lot more wood than it should for the Btu's I need, so the storage will help me get more efficient. I also hope to hook up the pool next season and (when I get it done) an 1200 sqf shop. The house, counting all 3 floors, rings in at 3400 ftsq. We installed floor heat in the whole downstairs, and will install rads upstairs.
Being you are building new, you may have a heatloss done on the structure, this will help with the choice of unit, I wonder if a 25 would even be enough?
Wondering if you are talking with the same guy that I bought from..( PM me on that)

Henk.

 

[BrownianHeatingTech]

Being you are building new, you may have a heatloss done on the structure, this will help with the choice of unit

Ditto. You should have a proper heat loss done on your design. Of course, that will only cover the structure, and not the pool, but it will be a vast improvement even over educated guesses.

If you intend to hire a contract to do the work, get him involved now, and he'll do it as part of his design. If you will be doing it yourself, it's worthwhile to hire someone to do a design for you (particularly since radiant requires a bit of engineering to run right, beyond what other require.

There's no replacement for proper engineering of the system. I could certainly make some good guesses as to what you need, but that can't compare to actually sitting down with the blueprints and feeding the numbers into the computer (or using Manual J by hand, if really bored...).

Joe Brown
Brownian Heating Technology
www.brownianheating.com

 

[Nofossil]

I'll echo Joe's advice. There are some other factors to consider, though. While you certainly want to get a unit that's big enough to cover your worst-case heating load, there are some considerations in determining how much bigger to go.

Gasifiers are finicky to start, but are very happy when they're running at full output. A smaller unit will have to run longer per start - not a bad thing. I'm heating a 3500 square foot house, domestic hot water, and a hot tub with an EKO 25 and 880 gallons of storage. The only downside is that if I want to heat up the storage before we leave, I have to plan well in advance, as it takes four or five hours to get it to temp.

One critical number that you want to get is the peak heating load - how many BTU/hr can the baseboards / radiant heat zones absorb? This is very often much less than the normally recommended boiler sizing. In my case, it's about 30,000 BTU/hr while my oil boiler is 120,000 BTU/hr based on the standard calculations. Oil boilers are fine cycling on and off, and being off 80% of the time. Not as true for wood boilers.

Too big a difference between the boiler capacity and the heating zone capacity doesn't make you any warmer any quicker.

All in all, my opinion is that this is not a case where bigger is necessarily better - just make sure it's big enough.

 

[Eric Johnson]

With no storage, temps in the low teens and an average house temp between 75 and 80 degrees, the EKO 60 still idled from time to time over the weekend.

Ideally, it would seem to me, your storage should be able to absorb the entire output of the boiler through one firing cycle. That way, you should be able to fire the boiler in the summer to heat the tank for DHW.

 

[MALogger]

Hi Eric,

Is that picture from this last storm?? I only got a little snow and rainy mix.

Craig

 

[Eric Johnson]

That's from last year, but we got about that much snow over the weekend. Check out the Current Weather webcam. That's where I work--up north of where my house is.