Newbie Eko-60 Install

[HeatFarmer]

I am a total newbie at this Gasification boiler stuff. Back in Feb of this year I spoke with two local experts who have installed tons of systems and we sketched out a plan where I would do the work, and they would provide some consulting. However, my time frame didn't seem to match theirs and I can't contact them, so I am left dealing with this on my own. I used to build elaborate luxury homes, but this heating system has me stumped.

Attached is a sketch--crude at best--of how the plan might work. I've just ordered an Eko-60 to go in the attached barn on the house. It is roughly 100ft from where 1000 gallons of water storage will some day live--if I can find the tanks which will fit in the cellar..... I'm envisioning two 500 gallon propane tanks. The cellar is under the heat load and stays at a pretty stable temperature. My idea is to pump the tanks full of as much heat as I can crank out of the 60--upwards of 190 to 200F. A Coil in the tanks will feed 6-8 cast iron radiators in the house. Another coil in the tanks will heat DHW. Right now I have a failing on-demand propane unit which I will by-pass and plumb the in/out hot-water line right through the coil in the tank, with a mixing valve placed on the hot-water side of the loop to steady temps. I assume I will need the same thing in the radiator zone. Not sure where or how that would go.

Additionally, out in the barn and attached shop I will have a radiant slab which nominally I will heat minimally. The slab can also act as a heat sink/dump to store extra heat or to bleed it off if we have too much going to the tank.

I have seen radiant systems installed. I have run miles of Pex. I can plumb castles. But this "simple" plan has me stumped. Any input would be most welcome! Am I way off base in this? What parts should I consider? Along with the EKO-60 I purchase Cozy Heat's full installation kit, which I assume, for my system, is actually only a partial kit.....

I would love feedback. Thanks.

 

[henfruit]

Hello ,Iwish we had met before.I am a vigas boiler dealer in eaton nh,just south of conway.When we sell a boiler to customer we supply them with drawings for there plumber to follow for a proper instalation and wiring for the pumps and aqastats.I may be able to give you help.There are posts on this web site on how to plumb your system, take a look at them as they are helpful.

 

[HeatFarmer]

Henfruit,

thanks for replying.... I decided against the Vigas because of costs.....it just pushed my budget too thin. I need the saved money to get the pumps/aquastats,etc. It's too bad, because I liked some of the features of the Vigas over the EKO, but it's done..... I've been looking at all the info I can in the forums, and I'm gaining some idea on how to get this thing going, but none of the systems seems quite the same..... I'm not using any additional boiler, and I am planning on taking the DHW straight from the storage tank via heat exchanger, without an additional tank. I am sure I will figure it all out as I get into the project, but I really don't need too much trial and error as my time is already stretched thin on the farm and a new barn needs built and winter is on the way.......

 

[Clarkbug]

HeatFarmer,

Not sure why you would have an additional coil in your tanks for the heating hot water. I would think that you only need the DHW coil, as the rest can just be pumped into and out of the storage tank as it is needed. Also, I would suggest that you want the radiant heat to come out of your tanks as well, as opposed to directly off of the boiler mains. It lets you pull your storage to a very low temp. Another alternative would be to set up a mixing valve off of the return to the boiler only to take advantage of the lower return water temps, you just need to watch the return water temp to the boiler.

You may want to consider upsizing your PEX run from 1 1/4" to 1 1/2", given the BTU output of the EKO 60.

Just a few hints from a relative newbie, so take those items with much salt!

 

[HeatFarmer]

Clarkbug,

I completely agree with you on the radiant coming off of the tanks rather than the boiler...forgot that I was going to do that.
The simple answer for the Pex size is that I already have the 1 1/4...but I could possibly add another 3/4 line along side each run to beef up the flow?

I'm not quite reading you on the coil issue.... I am (probably mistakenly) viewing the liquid in the tanks as static...like a battery, no? So I would need a coil to heat the DHW, and a coil to heat-exchange the water going from the boiler. Wouldn't this be the safest bet for the life of the boiler?

 

[700renegade]

The water in the propane tanks is not static ( usually ). I've never seen a layout where heat transfer coils were placed inside a pressure vessel. Not only is it physically hard to accomplish and expensive, it bends a lot of 'rules'. For example a goal with storage is low velocity to stratify the heat in the tank - a goal with transferring heat off a coil is high temp differential and high velocity.

Just load your hot boiler water into the top of the propane tanks / return to boiler off bottom as so many diagrams show and forget that coil. If you have a non pressure capable or non O2 barrier system to feed, do it via a plate exchanger external to the tank.

If it were me, I'd charge my DHW in this system using a sidearm exchanger on my existing hot water heater ( you have to retain it anyway for summer use ) and eliminate that DHW coil too.

By the way, don't forget expansion tanks - you're going to need plenty with 1000 gallons expanding when hot.

 

[HeatFarmer]

The water in the propane tanks is not static ( usually ). I've never seen a layout where heat transfer coils were placed inside a pressure vessel. Not only is it physically hard to accomplish and expensive, it bends a lot of 'rules'. For example a goal with storage is low velocity to stratify the heat in the tank - a goal with transferring heat off a coil is high temp differential and high velocity.

Just load your hot boiler water into the top of the propane tanks / return to boiler off bottom as so many diagrams show and forget that coil. If you have a non pressure capable or non O2 barrier system to feed, do it via a plate exchanger external to the tank.

If it were me, I'd charge my DHW in this system using a sidearm exchanger on my existing hot water heater ( you have to retain it anyway for summer use ) and eliminate that DHW coil too.

By the way, don't forget expansion tanks - you're going to need plenty with 1000 gallons expanding when hot.

I wasn't really thinking of the propane tanks in my system as pressurized....I was just using them because they are the only vessel to fit in my cellar space. I was thinking more of an unpressurized storage system, hence the heat exchangers. I was actually thinking of going for high temp diffs....drain the system right down and then fire the heck out of it at max burn...no idling.

As for the DHW...I have no tank now. I am using a failing on-demand system. It is old enough that it can't handle hot water coming off the new boiling system. I am trying to do away with hot water tanks and redundant, costly things.....In the summer I believe I can fire the gasifier once a week--burning paper garbage and some minimal wood--again.....firing it as hot as it takes, only as long as it takes to raise the temp in the tanks to supply DHW.

My drawing didn't show expansion tanks because I forgot to include them, I assumed they were a given. And, again, I was not viewing my system as a pressurized system...so expansion requirements are much smaller.

 

[Clarkbug]

If you arent going to pressurize your system, you dont need to bother using propane tanks... You can use a liner in a box, and build it yourself, or talk to Tom in Maine here on this site. This way you dont have to rig them into the space, you just build them there.

In my case I was able to find storage tanks that fit through my cellar door, so thats whats going in. But I was thinking of going the unpressurized route. For all of your trouble, I do think you should at least consider a pressurized system. If you want to stay unpressurized, you may want to re-think your tank. Also, if you are going un-pressurized, you wouldnt need to have an expansion tank, you just wouldnt fill your tanks all the way full and allow them to be vented. That way the expansion stays inside the tank anyway.

As far as your line size, an EKO 60 is rated at 205,000 BTU/hr. If you assume a delta T of 20 degrees, then you have a flow rate of 20.5 GPM to move that many BTUs. (using rule of thumb, back of napkin stuff) That will be a tight squeeze in your 1 1/4, and a pressure drop around 16 psi for just the piping. I dont know that you will want to pay for the pump to push it that far...

 

[HeatFarmer]

If you arent going to pressurize your system, you dont need to bother using propane tanks... You can use a liner in a box, and build it yourself, or talk to Tom in Maine here on this site. This way you dont have to rig them into the space, you just build them there.

In my case I was able to find storage tanks that fit through my cellar door, so thats whats going in. But I was thinking of going the unpressurized route. For all of your trouble, I do think you should at least consider a pressurized system. If you want to stay unpressurized, you may want to re-think your tank. Also, if you are going un-pressurized, you wouldnt need to have an expansion tank, you just wouldnt fill your tanks all the way full and allow them to be vented. That way the expansion stays inside the tank anyway.

As far as your line size, an EKO 60 is rated at 205,000 BTU/hr. If you assume a delta T of 20 degrees, then you have a flow rate of 20.5 GPM to move that many BTUs. (using rule of thumb, back of napkin stuff) That will be a tight squeeze in your 1 1/4, and a pressure drop around 16 psi for just the piping. I dont know that you will want to pay for the pump to push it that far...

I live "next door" to one of the innovators of all of this technology.....in fact, he used to own this farm. I've been to his shop, and he showed me the flaws, 10-12 yrs on, in home built tanks. He steered me towards a dairy bulk tank or propane tanks, even unpressurized, because we can heat them hotter. I want to push these to 195 or 200 or so, if I can. EPDM liners can't handle that. 1000 gallons of homebuilt storage won't fit in my space. But two 500 gal propane tanks will slide in there just nicely, along with a box of insulation built around them. Unfortunately, his shop is so busy with installs and R&D I hate to bug him, and cannot afford his consultation rates.....


I will consider a pressurized system, now that I am gaining some insight into them.....

Thanks for the input....that's why I drew such a simple diagram....to learn the flaws and educate myself about these systems.

 

[Clarkbug]

I understand where you are coming from, and its great that you have a local guy that you can easily go talk to if you ever really really had a problem.

I guess my thought was also that if you can get the big tanks, you would be doing yourself a disservice by not going pressurized with them.

Also, I should note that depending on your heat emitters, you may be able to pull a much bigger delta than the 20 degrees (since you had radiant heat planned, I dont know what your zones are), which would lower your flow rate.

I would read up here : https://www.hearth.com/econtent/index.php/forums/viewthread/79570/

Mr. Dudley has provided me a wealth of information/advise/confidence in the system Im laying out, so he could also probably provide you some good insight (and correct anything that I am saying that is wrong....)

 

[woodsmaster]

The water in the propane tanks is not static ( usually ). I've never seen a layout where heat transfer coils were placed inside a pressure vessel. Not only is it physically hard to accomplish and expensive, it bends a lot of 'rules'. For example a goal with storage is low velocity to stratify the heat in the tank - a goal with transferring heat off a coil is high temp differential and high velocity.

Just load your hot boiler water into the top of the propane tanks / return to boiler off bottom as so many diagrams show and forget that coil. If you have a non pressure capable or non O2 barrier system to feed, do it via a plate exchanger external to the tank.

If it were me, I'd charge my DHW in this system using a sidearm exchanger on my existing hot water heater ( you have to retain it anyway for summer use ) and eliminate that DHW coil too.

By the way, don't forget expansion tanks - you're going to need plenty with 1000 gallons expanding when hot.

The nice thing about a coil in the tank for DHW is you dont mix the water in storage so it stays stratified. I have a side arm and but wish I had a coil in the tank. The water in the tanks all gets to the same temp with the circ. running all the time. Not a real big deal for me becouse I can use lower temp water for heat with rads and radiant but......

 

[HeatFarmer]

Also, I should note that depending on your heat emitters, you may be able to pull a much bigger delta than the 20 degrees (since you had radiant heat planned, I dont know what your zones are), which would lower your flow rate.

I'm not sure of the zones myself just yet. I am thinking of the slab in the barn and shop as one zone--they are more heat sink/frost heave prevention than anything and shouldn't need to be separated. I am not sure if the boiler protection safety above the boiler counts as a zone. The other zone is really just the radiators in the house. Because they can be adjusted individually at each cast-iron unit, then should be able to all be on one zone, even if they are spread throughout the house. Although, I'm not sure how that works out with the thermostat.....Not even sure if I need more than one thermostat in the system....one in the house and one in the barn/shop....

It seems to me that using one single coil to both heat the tanks from the boiler, and supply the zones, I should be able to dissipate the heat any number of ways depending on the requirement. Because I would be using the storage for DHW I think the lowest we would allow the tanks to get in the shoulder season would be 135....this would then absorb quite a bit of heat to bring back up to 200F. If I open up the loops into the slabs---don't know if there is some way to automate this or if it's just a matter of attention to detail--then I could regulate the delta even more.

 

[Clarkbug]

The slab system will definitely be its own zone. The boiler safety is typically not a zone. If your piping for the house radiators is just one loop, then that would be a second zone. You would have one house thermostat that would kick on a circulator for that loop, and another for the shop. You could plumb in an overheat aquastat to kick on a zone as an emergency heat dump, but the radiant may not be the best choice, since it will need "colder" water anyway. Big thermal masses like that wouldnt be good for a rapid dissipation of heat.

For DHW I think you will find you can go lower than 135 and still have more than enough. If you read up on here, others get down into the 120 range, or lower. Depends on how hot you like your showers I guess.

 

[bpirger]

Typically you don't want to put water into a slab over 120, 130-140 peak. Dumping 200 degree water into the slab during aN "OVERHEAT" period may have some bad consequences on your concrete. Plus, whatever heat you put into the slab, don't count on being able to retreive that for house heating. The slab radiates the heat well and won't stay at 120. Good thing, can you imagine working/walking on a 120 floor, not to mention everything sitting on it reaching such a high temp? Typically slabs are brought to about 75-85. So you will likely want a mixing valve to control the water temp going to the slab. I do all mine with variable speed mixing pump controllers, others use actual mixing valves.

How does one get a coil inside a propane tank? PEX does make a great coil for a HX, though it will work, but considerably longer than copper, and I don't know how this woud be suspended in the tank.....but I've never dealt with tanks. All my concerns with tanks, propane, welding, loops inside, etc. led me to the Garn.

A third comment....you mentioned buring paper trash during the summer. I'm not sure you EKO will be happy if you do much of this, others will have to comment. Typically you want to make sure the HX in the EKO stays clean....the whole thing really...and not sure what happens if you are really burning loads of paper. That sounds a bit more like an outdoor smoke dragon.... I burn my Garn all summer for DHW. If I turn the DHW down to 110, which has been fine for my family of teenage daughters (a whole different topic there isn't time in life to write about) I burn every 4 days. I have 1500 gallons heated up to 190.

Have you performed a heat loss calc to know what your heat load is? This way you can get a good feel for how long your storage will last if it is giving you an X temperature swing with Y gallons. 8 BTUs/gallon/degree. So 1000 gallons gives you 8000 BTUs/degree. If you can get a 200-130 degree swing, 70*8000=560,000 BTUs. If you know your house wants 50Kbtus/hr during the winter, you'll see you have 11 hours if running on storage totally. I'm just not sure you have run some numbers to know what you can expect from the system....nothing worse than going through all the work and effort and finding you aren't getting what you thought/need. Disappointed expectations....geez, that reminds me of the teenage daughters!

 

[woodsmaster]

The slab system will definitely be its own zone. The boiler safety is typically not a zone. If your piping for the house radiators is just one loop, then that would be a second zone. You would have one house thermostat that would kick on a circulator for that loop, and another for the shop. You could plumb in an overheat aquastat to kick on a zone as an emergency heat dump, but the radiant may not be the best choice, since it will need "colder" water anyway. Big thermal masses like that wouldnt be good for a rapid dissipation of heat.

For DHW I think you will find you can go lower than 135 and still have more than enough. If you read up on here, others get down into the 120 range, or lower. Depends on how hot you like your showers I guess.

low temps on DHW depend on how fast you need the water to recover, how fast your using it and what kind of hx and the way it is setup. I have a side arm
on a 80 gallon water heater. I dont have a circulater on the domestic side and with a family of 5 if we do laundry, dishes, and bath we can run out of hot water
If the temps on storage drop below 150 F and we have a high demand period.

I think if I add a circulator to the domestic side I could probably let storage get down to 125 or 130

 

[700renegade]

Heatfarmer - you might need to step back a bit and rethink this system. First off there is no way you are going to charge your tanks to 190 or 200* - ever - using a HX coil, a 1.25" pipe and an ECO boiler. The boiler controller maxes out at 195* and you'll need at least 20* DeltaT to transfer meaningful BTU to the tank. Go to pressurized storage and you'll get your 20* back.

From my perspective, loading 1000 gallons of scalding hot water into my home in the middle of summer just to get DHW is silly. I'd throw in a cheap electric water heater to use in shoulder season and summer and call it good ( I only pay $0.05 / kwh for off-peak electric, so it is very inexpensive to run ). Paying for Air Conditioning or being hot is bad enough without having those hot tanks ( no matter how well insulated ) down in the cellar.

Is there a reason you cannot stand a 1000 gal or two 500's vertical in your new barn you are building? All of your pipe size/GPM/BTU problems are minimized when the boiler and it's storage are near to each other. DHW is a bit tougher though.

 

[HeatFarmer]

Thanks for all the help & input everyone. I've been mulling over everything said and have been re-designing the system to match available materials & budget. Look for my new post on the install process.

 

[Hunderliggur]

I have a pressurized storage system with in tank heat exchanger. My radiant system (by the Radiant Company) uses potable water through the radiant floor system. It works fine and has an added benefit, I was able to run my COLD water through the floor in the summer for some additional cooling (basement RH is kept less than 60F so I don't have condensation problems). I will be adding a second in tank HX at a later date for a solar input to storage. The boiler circuit (not shown) is a simple loop from bottom of storage, to boiler, to top of tank, with a DANFOSS protection valve and circuit. We have had discussions about potable radiant systems but as far as I am concerned, mine works fine. I get a consistent 20F delta (110-130) or more over a wide range of temps. I use a mixing valve on the HX output to limit to 130F. I have 3 zones at 3 GPM each. I could have bought a larger in tank HX but it was not needed. I got the HX from Mark at AHONA.