EKO-25 placed in workshop

[Blue Tornado]

Hello to all at the Hearth.com

Thank you all for being here and sharing so much good information. I have wandered this site for a short while and gleaned a great deal from your experiences. At this time I have sent payment for an EKO-25 boiler and have the house side established. The wood pile consists of about an 8 cord mix of oak, maple, cherry, birch and poplar which is cut, split and piled 4 months ago. Will stack this spring. Still have another 8 cords of oak as pulp logs that I will process over the summer.

Now I am looking to hear opinions on the following plans.

Place an Orlan EKO-25 in a 900 square foot well insulated workshop with 250 gallons of insulated and pressurized storage. The underground run to the 1200 square foot, averagely insulated 1 story house is 30 feet. In the crawl space of the house are four 100 pound propane tanks laying horizontal for storage and radiant. Finned baseboard emitters in the house. The entire system will be pressurized.

The plan is to have the boiler and main storage as the primary loop and then pipe to the house as secondary. Primary loop of 270 gallons and secondary loop of 112 gallons. The soil conditions are exclusively sand and I will use rigid foam as a form for closed cell spray foam on piping, covered with 4 mil plastic.

My questions first .. .. .. with my assumption after.

1) What size piping to get to the house? .. .. .. One inch.
2) Will there be enough radiant heat from the boiler to heat the shop? .. .. .. I have no idea.
3) Does exposing a portion of storage seem like a good idea? .. .. .. Leaning more toward fanned hx.
4) Will the shop be too warm in the summer to run dhw?
5) For dhw, sidearm or flat plate? .. .. .. Flat plate with thematic 3-way valve
6) Will the EKO-25 be capable of this?.. .. .. Sure
7) Will the EKO-25 take another 1400 square foot insulated structure? .. .. .. Seems iffy

 

[maple1]

Re. 1, from what I've read not all 1" is the same size - i.e. the recent logstor thread. 1" might be marginal? But I can't say from experience, just what I've read here.

Re. 2, 3 & 4, if you just build an insulated box around your storage, with one end built like a door so you can open & close it a bit when you want (or hatches in the top & bottom to let air through, or whatever), you can get all kinds of heat in your shop with it open, and keep it in the tanks when heating DHW in the summer.

Re. 5, I went sidearm but I'm not sure that was the best solution. I know they're prone to scaling if your water isn't the best, but I think plates are too though. So you'd flush periodically either way. Based just on what I know, I think if your setup would allow DHW gravity flow, I'd go sidearm, if it will need pumping, I'd go plate.

Re. 6 & 7, I'd likely agree.

 

[Fred61]

I have the EKO 25 with 500 gallons of storage in the basement of my 1000 sq/ft very well insulated ranch style home. It works well for me and the EKO only runs between 3 and 5 hours per day to charge storage. I'd like to tell you the heat loss numbers of the home but in the 5 years I have run the boiler I have made a concerted effort to super insulate the home a little each year since it needed rework when I purchased the place. As I rework each room, I add 2 inches of polyicocianate insulation on the inside of the studs before attaching drywall. I actually went as far as removing the trusses and replacing them with new ones and made room for another 16 inches of celluose insulation in the attic. It has become a hobby (or a sickness) but I'm having fun in my retirement. So you see that the heat loss calc changes approximately every 6 months.

What I'm getting to with all this babbling is that first you should do a heat loss calc. on your home. Second; I can tell you that 250 gallons of storage is almost like having no storage. It's not worth the money to purchase and install all the pipe fittings necessary for only 250 gallons. With my very low heat load, 500 gallons is the lowest I would go. You say you have a moderately insulated house so chances are your heat load is higher than mine (whatever mine is). Storage capacity is determined by heat load and boiler capacity but I don't need to know your heat loss to know that 250 gallons is too small for any installation.

I have a walk out basement and when I run my boiler it only runs for 3 to 5 hours and during that time, the basement gets up to 70 to 72. When my storage is up to temperature I shut off the boiler master switch and coast for the next 20 hours or so, running on storage. The only thing that keeps my basement from going below 65 during that period is the heat loss through the insulation on the tank and a small amount of exposed piping. The more hours you run your boiler, the more it will benefit your shop with the loss from the boiler, stack, and near boiler piping.

 

[Blue Tornado]

Hello Maple and Fred. Thank you for your input.

I will be pondering the pipe diameter a bit more and the material to be used. Unless I hear of good reasons not to use a plate exchanger for dhw, that is what will happen.

As for the storage issue, I am aware of the bigger is better theory and truly wish there was more space. In this situation it is a trade off, more boiler water storage = less floor space. Life is full of compromise.

Fred, your burn and draw times impress me, congrats to you. To accomplish your reheat in 3 to 5 hours, how much wood are you using? Full loads, half loads, 3 loads? As my system's water capacity is 25% less than yours I will not expect to see the same results and hope they aren't horribly different. With your EKO 25, how long does a 3/4 firebox burn at full throttle?

From the results Fred gets in his basement temperatures radiating the boiler; it seems that an exchanger isn't necessary in this case. I like the idea of hatches for adding heat as needed in the event of truly frigid times.

 

[maple1]

FWIW, I measured my firebox at right around 3 cu.ft. useable space. Practically, not all that gets used due to wood being shorter than the firebox & air spaces at the top etc., but when I get it about as full as I can easily get it, it is pretty well burned out in 4 hours. If I'm reloading I try to do that after 3 hours to have a better coal bed to load onto - but the 3 hour thing doesn't always happen.

I'd concur with Fred on his comments that 250 gallons is not much storage. 110 gallon tanks are 30" x 4ft - you could fit a few of those in a pretty confined space with some creative stacking and some extra plumbing. Might be worth considering? Also might come down to what you can find in your area.

 

[Fred61]

I just went down and lit my daily fire. Top of storage was 137 degrees which is about normal for a day with a few hours of sun. Yesterday it was down to 128 mostly because it was a dark day. I agitated the cold coals in order to separate some of the gray ash so it would drop into the secondary chamber. Spread out the charcoal over the nozzle and loaded 12 dry splits in the burn chamber. Only two of the pieces were as large as a playing card with the remaining ones being smaller. That brought the firebox to about 3/4 full. Removed the ashes from the lower chamber making sure the U-blocks are without any build-up of ashes. stuck the propane torch up the nozzle and lit the coals for about 3/4 of a minute. Started the combustion fan, closed the lower door and pulled the bypass handle.

I'll check it at 6:30 to see what the tank temperature is and guess at that time how much wood I'll need to add to bring the tank to 184 and add wood. Perhaps 5 or 6 more pieces. I suspect the tank will be up to temperature by 7.30. It's not urgent that I check it at that time because things start going into slow motion as the tank temperature rises and the controls will take care of everything but I like to shut off the boiler when there are some coals left and shutting it off disables the cycle timer. Perhaps a little more wood will be needed if the tank temperature is down in the 120s or if some zones happen to be drawing.

When starting a new fire, which is every day in the dead of winter, I always concentrate on getting all the ash off the target bricks. I've always been nutty about heating and cooling objects evenly. Probably comes from my days when I was glass bonding. It even spills over to operating an automobile. When I make a stop, say at a stoplight I am a creeper. I keep allowing the vehicle to move so that the area under the brake pads gets a chance to cool close to the rest of the rotor. Of course when I'm "creeping" I don't make eye contact with the driver next to me and make him think I want to drag. I've never had a warped rotor. Ceramic blocks on the other hand don't warp, they crack.

On storage, "bigger is better" when comparing 500 gallons to 800 gallons but comparing 250 to 500 is not a comparison and bigger is the only one with any value.

 

[Blue Tornado]

Hello again Fred:

Thank you for sharing your procedures in loading and lighting the EKO 25. Have you adjusted your splitting size to match this boiler? What species do you burn and what length do you cut to? So leaving ash to protect the castings is not valid in your mind? Just guessing but I would say the point directly under the nozzle would take the lions share and be first to deteriorate. Does the ash begin build-up within a few minutes? Have you run the figures on the actual efficiency of your boiler only?

My apology for so many questions.

I plan on weighing the wood through the first winter to get a baseline and to share with others. At present I will go with the manufacturers claims, my heat loss assessment (which jives closely with last winter's propane use) to establish expectations. This will be the first time dealing with any type of boiler so the only comparison is to propane forced air. No doubt there will be a financial gain.

In the future I will be addressing the issue of storage. I am aware of the importance of size in that regard but am working within existing parameters. In my mind at this point; 250 plus the 20 in the boiler, plus 112 in the crawl space is way better than a 20 gallon boiler with 6 gallon system.

Thanks again for your input.

 

[Fred61]

My wood is 18 inches and mostly hard maple with yellow birch and white ash mixed in. The small splits work for me in a couple ways. First it dries better and it is easier to light. Reaches gassification quicker and appears to burn hotter. No, I don't weigh my wood. Have all the settings where I want them and they have been that way for four years so I'm sort of past the experimenting stage. My wood is dried for three years so every fire goes as expected. One of the first things I used to do first thing in the morning was check the temperature of my storage. I'm also past that.

You now know why I clean the target bricks. The reason I like to keep the upper chamber free of ash is because I don't want the moisture from combustion to deposit into the ash that is in contact with the steel water jacket and start corroding the steel from the sodium hydroxide (lye) in the ash. The u-bricks are still close to new condition.

Sleep on the storage issue. You may find a way to get adequate storage.