Eko to lpg boiler drawing

[huffdawg]

Heres a rough drawing of how my eko might be plumbed into my existing system.
Any thing im missing or done wrong ! Please feel free to critic .
I feel confident doing all the hands on stuff . But I am newbee as far as control and where the best location for all the control mechanisms.
one thing I was not sure of is how dhw will work if im bypassing the lpg boiler.

Huff

 

[stee6043]

Perhaps it's just the way you drew it - but you don't need the little jog off your Danfoss valve. Plug it right in line upstream of your circ, save a little plumbing.

Are all of the circs in your boiler loop existing? If everything in that loop is existing I think I'd simply tee the EKO in very close to the lpg boiler and utilize the current plumbing/controls for the load loops and DHW. I can't tell exactly right now...but I just don't like where you tie in....I think something is not going to work right, as you mentioned it may be DHW...

 

[huffdawg]

Yes everything on lpg boiler side is existing and yes I made a drawing error on the danfoss ,couldnt find the whiteout.
I will be installing the eko about 80' away from the lpg boiler. I will be putting a 2" pvc conduit in the same trench as the 1-1/4 pex supply and return line to the eko.
I will be able to fish whatever sort of signal wire I need to through this conduit.
I will put a feed water source in the trench as well.
I dont see how to make the dhw work without running the heated water from the Eko through the lpg boiler.Maybe a bypass from the dhw return to the eko return with some sort of way to route it back to the lpg boiler if it wanted to take over the demand for heat.

Huff.

 

[Gooserider]

I would tie in right where the existing tees are coming out of the LPG boiler, and possibly add a normally closed ZV on the return to the LPG boiler - set up the controls so that instead of firing the LPG, they pull from the EKO and it's pump, unless the EKO is cold, in which case you open the ZV and fire the LPG...

That way everything else in the system won't be able to tell which boiler it's getting the heat from...

The other thing I notice on your drawing is that it appears you are wanting to use your shop infloor as the overheat loop? If so, this probably isn't going to work, as you aren't going to get the needed gravity flow for circulation in case of a power failure - on an overheat loop the heat load needs to be above the boiler...

Also on the conduit - you might be better off to run 2-3 smaller runs (say 3/4" or 1") instead of a single 2" conduit - this will give you a bit more flexibility as you need to keep in mind that you absolutely NEVER should put AC power and signal lines in the same conduit... However you can run a bunch of Cat5 or equivalent through a 3/4" lline (at least 6 strands) and have a second pipe for your AC if you need it...

Gooserider

 

[huffdawg]

I would tie in right where the existing tees are coming out of the LPG boiler, and possibly add a normally closed ZV on the return to the LPG boiler - set up the controls so that instead of firing the LPG, they pull from the EKO and it's pump, unless the EKO is cold, in which case you open the ZV and fire the LPG...

That way everything else in the system won't be able to tell which boiler it's getting the heat from...

The other thing I notice on your drawing is that it appears you are wanting to use your shop infloor as the overheat loop? If so, this probably isn't going to work, as you aren't going to get the needed gravity flow for circulation in case of a power failure - on an overheat loop the heat load needs to be above the boiler...

Also on the conduit - you might be better off to run 2-3 smaller runs (say 3/4" or 1") instead of a single 2" conduit - this will give you a bit more flexibility as you need to keep in mind that you absolutely NEVER should put AC power and signal lines in the same conduit... However you can run a bunch of Cat5 or equivalent through a 3/4" lline (at least 6 strands) and have a second pipe for your AC if you need it...

Gooserider

The tees for the eko boiler to the lpg boiler are not existing yet . Thats how I would like to do it ,but I dont think the dhw would work as the return goes directly into the lpg boiler.

No I wont put any ac lines in with the signal wires . I have two other 1-1/4 conduits I installed when I built the shop . Also my shop has electricty too.

I was thinking I could power a circ p/p with some sort of ups. or I could also make another zone with baseboard heaters upstairs in the shop? would baseboared heaters have enough heat transfer for an emergency heat dump circuit?

Thanx Gooserider


Huff.

 

[WoodNotOil]

There is a simple solution to your problem. Firstly, the circ on the lpg return line is strangly redundant, there are circs to supply your dhw, radiant, and baseboards, so I fail to understand the purpose of a circ on the return line. If you eliminate that circ and tie the Eko return between the dhw return and the lpg, you will have what could be called a reverse flow parallel hookup. This means that if no zones (including dhw) is calling for heat, then the flow reverses through the lpg keeping it up to temp and ready to take over if the need arises. The water will flow through it and then out to the Eko on the return line.

Some on here will rightfully argue that heating one boiler with another is inefficient, but the upside of keeping a fossil boiler warm is that it can keep the gaskets etc. from the stress of going from stone cold to full temp every so often. I keep my oil boiler hot with my Tarm and simply created a polyiso jacket to increase the insulation around the boiler.

Lastly, yes baseboards are okay for overheat, so long as they are above the boiler. Size them to output around 10% of the btu rating of your boiler. I hope that helps.

Edit: You may even be able to do what I suggested above without having to take out the circ on the lpg return, but I am curious what it is for. Also, you may want to look at the sticky "Simplest Pressurized Storage System Design" which shows a type of parallel hookup that does not heat the second boiler. In your case you would just ignore the piping for the storage. See if you can make that work with your existing piping and then you would have the possibility of adding storage later using that design. Just a thought.

 

[Gooserider]

If you have something to block flow through the LPG boiler, then the return from the DHW tank will find its way to the return for the gasser. Basic rule of Hydronics - water is lazy, and will always flow in the direction of the lowest pressure - so it CAN'T flow into the LPG boiler if that path is blocked (it might not even go that way if the path isn't blocked. I would just move the connections for the EKO so it's on the LPG boiler side of that pump in the return line...

In terms of the overheat loop - yes you might be able to do a UPS powered pump setup, but I don't trust electronics for safety functions if I can avoid it - however baseboards will do fine for making an emergency dump loop, indeed I've often seen the recommendation being made to use junk fin-tube from the salvage yard or the "scratch & dent" area of the local plumbing supplier - often without the covers, it's cheap and most times appearance doesn't matter all that much... The only question is making sure there's enough length, and making sure there aren't any restrictions to gravity flow. IIRC you are supposed to get at least 10% of the boilers rated output, and figure on 150BTU per foot of fin-tube...

Gooserider

 

[huffdawg]

There is a simple solution to your problem. Firstly, the circ on the lpg return line is strangly redundant, there are circs to supply your dhw, radiant, and baseboards, so I fail to understand the purpose of a circ on the return line. If you eliminate that circ and tie the Eko return between the dhw return and the lpg, you will have what could be called a reverse flow parallel hookup. This means that if no zones (including dhw) is calling for heat, then the flow reverses through the lpg keeping it up to temp and ready to take over if the need arises. The water will flow through it and then out to the Eko on the return line.

Some on here will rightfully argue that heating one boiler with another is inefficient, but the upside of keeping a fossil boiler warm is that it can keep the gaskets etc. from the stress of going from stone cold to full temp every so often. I keep my oil boiler hot with my Tarm and simply created a polyiso jacket to increase the insulation around the boiler.

Lastly, yes baseboards are okay for overheat, so long as they are above the boiler. Size them to output around 10% of the btu rating of your boiler. I hope that helps.

Edit: You may even be able to do what I suggested above without having to take out the circ on the lpg return, but I am curious what it is for. Also, you may want to look at the sticky "Simplest Pressurized Storage System Design" which shows a type of parallel hookup that does not heat the second boiler. In your case you would just ignore the piping for the storage. See if you can make that work with your existing piping and then you would have the possibility of adding storage later using that design. Just a thought.

That piping and circ p/p just below the lpg boiler is called a modular piping system ,it came with the boiler. I read on the buderus boiler forum the warranty will be voided if you remove it .Maybe its needed to push the h2o through the heat exchanger im not sure .
I have a feeling my warranty on the lpg boiler wil be voided by adding another heating source too it anyways.
You can check out a pic of the return side of my lpg boiler on a previous thread by me " where to tee into existing lpg boiler" theres a few pics on there and some are better than others. So scroll down past the first couple.

Thanx WoodNotOil

Huff

 

[huffdawg]

If you have something to block flow through the LPG boiler, then the return from the DHW tank will find its way to the return for the gasser. Basic rule of Hydronics - water is lazy, and will always flow in the direction of the lowest pressure - so it CAN'T flow into the LPG boiler if that path is blocked (it might not even go that way if the path isn't blocked. I would just move the connections for the EKO so it's on the LPG boiler side of that pump in the return line...

In terms of the overheat loop - yes you might be able to do a UPS powered pump setup, but I don't trust electronics for safety functions if I can avoid it - however baseboards will do fine for making an emergency dump loop, indeed I've often seen the recommendation being made to use junk fin-tube from the salvage yard or the "scratch & dent" area of the local plumbing supplier - often without the covers, it's cheap and most times appearance doesn't matter all that much... The only question is making sure there's enough length, and making sure there aren't any restrictions to gravity flow. IIRC you are supposed to get at least 10% of the boilers rated output, and figure on 150BTU per foot of fin-tube...

Gooserider

I could possibly put a tee in for the eko return where the dhw return takes a 90 just before it tees in between the circ p/p and the boiler.
There isnt enough room for another tee above the circ p/p.

Seems like a few options and they all have their merits , I have two weeks to get it figured as Im at sea for a couple of weeks now.
Its sure nice having internet access on the ship.

Thanx GR.

 

[huffdawg]

Heres a rough drawing of how my eko might be plumbed into my existing system.
Any thing im missing or done wrong ! Please feel free to critic .
I feel confident doing all the hands on stuff . But I am newbee as far as control and where the best location for all the control mechanisms.
one thing I was not sure of is how dhw will work if im bypassing the lpg boiler.

Huff

I was wondering which would be a better way to plumb in the supply to the shop .a) closely spaced tees on the return to the boiler b). from the supply side and to the return side.
I am thinking b) because if I went with a) the flow would be restricted after going through the existing 3/4" inch plumbing on the house side?

Cheers Huff

 

[in hot water]

Is that a GB series Buderus boiler/ They are pretty adamant about piping that as a primary secondary loop. They do show options to the factory module to accomplish adequate flow through them Al HX.

No need for multiple expansion tank locations it messes with the hydraulics of the system when you install two inn different locations. Research some true P/S piping info and articles, with that boiler it needs to be correct.

hr

 

[huffdawg]

Sorry I didnt mention that the gb-142 is all ready in operation. . you can view a pic. of it on an earlier thread I started (where to tee into existing boiler). Its plumbed as per drawing above minus the eko and its supply and return lines. The reason I ask is that the gb side is 1" (not 3/4" made an error in the previous post), I have installed buried 1-1/4 pex that runs from my eko boiler room to the existing gb but is not tee,d in yet .

I was just concerned that the 1-1 pex supply line from the eko will be necked down to 1" at the gb . so I was inquiring about the best way to plumb my shop heating in . Closed spaced tee's on the return or the other way ,which is having a tee on the outlet side and a tee on the return side of the wood boiler?

What would you suggest would work as far as expansion goes as the one on the gb side is allready in place . The other expansion tk. came with the eko.

Hopefully you can understand my bad english.

 

[in hot water]

I would tee the EKO into the lines just below the boiler and below the DHW pump tee, with closely spaced tees.

The expansion tank needs to be sized for the entire system volume now. You can connect multiple tanks together at one tie in
point. I'd leave the tank under the GB and tee in the additional tank there. You can use pex to tie them together, they do not need to be mounded side by side.

Adjust the air charge in both expansion tanks to 12psi, or whatever pressure you intend to fill to.

I've run an EKO 40 for 4 years now and have never had an overheat, even with power outages, or when I forget to power it back up after working on it. With the fan off and tight door seals they seem to rev down quickly.

hr

 

[huffdawg]

Gooserider had suggested doing it this way earlier (If you have something to block flow through the LPG boiler, then the return from the DHW tank will find its way to the return for the gasser. Basic rule of Hydronics - water is lazy, and will always flow in the direction of the lowest pressure - so it CAN’T flow into the LPG boiler if that path is blocked (it might not even go that way if the path isn’t blocked. I would just move the connections for the EKO so it’s on the LPG boiler side of that pump in the return line). I cant understand how it will work GR's way as the return from DHW is on the discharge side of that circ p/p underneath the boiler and the return from the infloor and the baseboard heat is on the suction side of that p/p.

In hot water are you saying to put two close spaced tee's just before the DHW p/p and if I id it that way should I put a ZVon the return to the EKO to stop flow that way if the GB is firing.









thanx

 

[in hot water]

to tie an additional boiler into an existing piping will usually be a compromise, if the piping was not planned for it. For me it comes down to how much compromising you want to do to make it a simple addition, or how much you want to repipe and at what cost.

I am always of the opinion that primary secondary, as shown at the top of the site, is the very best for multi load, multi input, mixed temperature systems. A hydro separator IS primary secondary piping also..

It is the only way to assure every boiler input and system output gets exactly the right amount of flow regardless of which combinations are running.

All other piping systems will have compromises. We have talked about the drawback of series, but it still will work. Same with parallel or any combination of these systems.

If the goal is to maximize all the boilers and emitters the P/S is often the best way to go.

It does require more planning, perhaps more parts to P/S, sometimes 3 way zone valves can be introduced to limit the number of pumps.

A good design starts on paper with a working understanding of flow rates (gpm), pressure drop (resistance to flow), velocity (speed of fluid in the piping), expansion of the fluid, air and dirt removal, safety valve sizing and location, and control logic and design.

There is a lot of information to help with all of these choices, if you break it down to small pieces it is easier to grasp.

Hydronic contractors can spend a lifetime learning all the tricks and finer points of design, not to forget all of the choices of components to make it all happen.

hr

 

[huffdawg]

Gooserider had suggested doing it this way earlier (If you have something to block flow through the LPG boiler, then the return from the DHW tank will find its way to the return for the gasser. Basic rule of Hydronics - water is lazy, and will always flow in the direction of the lowest pressure - so it CAN’T flow into the LPG boiler if that path is blocked (it might not even go that way if the path isn’t blocked. I would just move the connections for the EKO so it’s on the LPG boiler side of that pump in the return line). I cant understand how it will work GR's way as the return from DHW is on the discharge side of that circ p/p underneath the boiler and the return from the infloor and the baseboard heat is on the suction side of that p/p.

In hot water are you saying to put two close spaced tee's just before the DHW p/p and if I id it that way should I put a ZVon the return to the EKO to stop flow that way if the GB is firing.

Ive been staring at this pic. for quite some time now , and im wondering if what im thinking might work to tie in my gasser.

-Remove the blue valve and drop down the black pk pump
-lower the tee for the DHW return
- install closed spaced tee's above the DHW return tee and below the lp boiler inlet.

:-/

Huff







thanx

 

[sgrenier35]

Not sure if this has been discussed, but I think that you need to keep flow through the lpg boiler in this case, as it controls the hotwater heater, and will fire on a call for hot water no matter what. I have only seen one of these installed with a wood boiler, and the plumber who installed the wood boiler, ended up leaving the lpg boiler to make hot water, and only set up the wood boiler to run the heat zones. I know that this isn't ideal, but there is some very significant control work to do to make the wood control the hot water as well. Good news the lpg boiler is very efficient.

 

[huffdawg]

Your right it isnt that ideal. I have three kids that will have showers till they run out of hot water. The boiler might be efficient but the price of propane here is about $2.85 a gal.
I told the heat tech. what I had in mind before I had him build this system and i'm starting to get a little disappointed now.
I also assumed the boiler wouldnt fire when DHW tank was calling for water while there was 160 to 180 degree water running through it.
Im wondering if my tech knows that.
Looks like its pretty straight forward to tie in to just the heat side , maybe I will do that for the time being and do some sort of redsign in the summer
unless somebody here can figure out a way that will work.

Cheers Huff