where to tee in to existing lpg boiler

[huffdawg]

I have attached a pic. and a drawing of my existing lpg boiler .
Id like to know where the best place to tee in a supply and return from a wood boiler.
It looks like it will be a bit of a chore.
Hopefully the attachments are legable.

Thanx Huff

 

[Gary S]

When I helped my nephew put his outdoor wood burner in we put a plate heat exchanger in the discharge line of the pump of the existing boiler. It works very well.

 

[huffdawg]

looks like the pic. of the boiler is too small .
I was hoping it would show the piping detail so the reader could see the limited space
Any way the reader can enlarge the pic. besides the thumbnail enlargement

 

[Gooserider]

What kind of boiler are you trying to attach? Will it also be pressurized, or is it a non-pressurized unit?

If it is pressurized, I would go for a tee on each side of the existing boiler, between it and the branches that go to the DHW tank, and also put a zone valve on one branch of each line, so that you can shut off flow through the unused boiler, and use the existing pumps for all your circulation.

If it is a non-pressurized unit, then you will need a flat-plate water-water heat exchanger, which I would plumb in the same way on the existing boiler side, and obviously have one additional circ on the wood side...

Can't make out much from that little picture (I suggest trying to upload 640x480 photos or close to it, don't try to do ultra high resolution...) but it looks like it's going to be tight no matter what you do, you may have to do some fairly extensive rework on the entire near-boiler piping setup to make room.

Gooserider

 

[huffdawg]

What kind of boiler are you trying to attach? Will it also be pressurized, or is it a non-pressurized unit?

If it is pressurized, I would go for a tee on each side of the existing boiler, between it and the branches that go to the DHW tank, and also put a zone valve on one branch of each line, so that you can shut off flow through the unused boiler, and use the existing pumps for all your circulation.

If it is a non-pressurized unit, then you will need a flat-plate water-water heat exchanger, which I would plumb in the same way on the existing boiler side, and obviously have one additional circ on the wood side...

Can't make out much from that little picture (I suggest trying to upload 640x480 photos or close to it, don't try to do ultra high resolution...) but it looks like it's going to be tight no matter what you do, you may have to do some fairly extensive rework on the entire near-boiler piping setup to make room.

Gooserider

hopefully this is a better pic.
I will be ordering an Eko 40 tommorrow ,hope to have it at home by the new year.
I also have a line on some propane tanks . Im not sure if I will use a 1000 gal. or two 500 gal tanks.
I think I will hook up the boiler without storage initially.
Yes it looks kind of tight where you are suggesting ,hopefully not to much reworking lol.
Im also a little lost on how the control part will work as all my thermastats are already in for the existing boiler .

How does it work with pressurised , would both boilers and the storage tks. all use the same water.
My existing boiler uses no water treatment chemicals .


Cheers Gooserider Thanx .

 

[mhearts]

Here is a picture of my setup tapping into my LP boiler. The cold water return manifold was used to make the connection. The two insulated lines are the connections to the EKO40. The pipe with red tape is the hot water in and the black line above it is the cold water return. It is inportant to keep the distance between those two point to a minimum.

 

[mhearts]

It is also important that the hot water connection is below the cold return

 

[huffdawg]

It is also important that the hot water connection is below the cold return

That definately would make life easier, there is a lot more room on the return side of my boiler.

cheers.

 

[huffdawg]

It is also important that the hot water connection is below the cold return

That definately would make life easier, there is a lot more room on the return side of my boiler.

cheers.

heres a more detail pic. of the return side .
Would there be any issues teeing in below the lowest isolation v/v on the bottom right.

 

[huffdawg]

Here is a picture of my setup tapping into my LP boiler. The cold water return manifold was used to make the connection. The two insulated lines are the connections to the EKO40. The pipe with red tape is the hot water in and the black line above it is the cold water return. It is inportant to keep the distance between those two point to a minimum.

There is no check v/v between them?

 

[mhearts]

correct.. there is no check between them. In the picture provided I can not locate the the return into your LP boiler.

 

[huffdawg]

correct.. there is no check between them. In the picture provided I can not locate the the return into your LP boiler.

Its the copper line that has the bottom right ball v/v on it, after which makes a right angle to the left and the carries on to the blue isolation v/v before the black p/p which feeds the boiler.

 

[huffdawg]

Here is a picture of my setup tapping into my LP boiler. The cold water return manifold was used to make the connection. The two insulated lines are the connections to the EKO40. The pipe with red tape is the hot water in and the black line above it is the cold water return. It is inportant to keep the distance between those two point to a minimum.

What do you do, isolate your lpg boiler or run eko 40 boiler hot water right through it.

 

[mhearts]

The LP boiler does come up to temp when the EKO loop is up to temp since one of the LP zones has a mixing valve in it to allow water to circulate back to the boiler return.

Once a zone in the LP boiler system opens and a pump for that zone turns on. It will suck the water from the incoming EKO feed(with red tape) and bring it thru the boiler, thru the zone and then back to the return line where it is sent back to the EKO.


It looks like you can tap right into your return line below the red handle valve in your picture.

 

[huffdawg]

Do you have storage on your system? Wouldnt the lp boiler start to fire when the storage tk. droppped below 160 °F . I have low and high temp zones.

Cheers Huff

 

[mhearts]

I am running without storage. The LP Boiler would fire if temp dropped, but i have the boiler shut off so it will not. If I am away for an extended period I turn the LP boiler on and it would indeed fire up, If I was away for several days I would isolate the EKO and the LP boiler with manual shutoff valves.

I also have low temp and high temp zones in my system and they all behave nicely. If all zones demand heat at the same time the EKO does struggle ...if it is in the single digits. But other wise it keeps up nicely without storage.

 

[huffdawg]

I am running without storage. The LP Boiler would fire if temp dropped, but i have the boiler shut off so it will not. If I am away for an extended period I turn the LP boiler on and it would indeed fire up, If I was away for several days I would isolate the EKO and the LP boiler with manual shutoff valves.

I also have low temp and high temp zones in my system and they all behave nicely. If all zones demand heat at the same time the EKO does struggle ...if it is in the single digits. But other wise it keeps up nicely without storage.

Ok I get it! I didnt know if my honeywell aquastat would work if my boiler was shut off, I,ll have to check that when I get home .
I work on a ship, two weeks on two weeks off . I get home Jan 2. I will go to the US and pick up my Eko 40 on the 4th.
Then all the fun stuff will get under way.

How many ft² do you heat and how long of burn times do you get.

Thanx for all the help.

Cheers Huff

 

[Gooserider]

Essentially there are two main approaches - with lots of variants so it can get confusing...

What I was suggesting, which would be a challenge with your tight plumbing layout, is a parallel setup so that you have two branches feeding the load (all your zones, DHW, etc) - One branch with your wood boiler and optional storage, and the other branch with the fossil boiler - set up so that you only get flow through the branch that is supplying heat - so that your fossil boiler won't try to heat the storage or wood boiler, and the wood won't try to heat the fossil boiler...

What it looks to me like mhearts is suggesting is a "primary/secondary" style setup, using closely spaced tees on one side of the fossil boiler, so that the wood boiler circulates its' water in a loop that the LP boiler pulls off and sends through itself and the distribution system rather than firing...

Either approach (and probably several others) would work reasonably well, though some might be more efficient than others... I think the approach I was suggesting is arguably the most efficient as it doesn't have any potential heat losses through the unused boiler, and doesn't require powering any additional pumps...

In every case, the basic control strategy is pretty much the same - intercept the call for heat coming from the thermostat(s) and send it to the wood side if that is hot enough, and the fossil side if it doesn't... The details will vary, but if you keep this basic idea in mind then it all makes sense... (Even a fancy setup like a NoFo controller will still do the same basic thing, just more elaborately)

Gooserider

 

[huffdawg]

Essentially there are two main approaches - with lots of variants so it can get confusing...

What I was suggesting, which would be a challenge with your tight plumbing layout, is a parallel setup so that you have two branches feeding the load (all your zones, DHW, etc) - One branch with your wood boiler and optional storage, and the other branch with the fossil boiler - set up so that you only get flow through the branch that is supplying heat - so that your fossil boiler won't try to heat the storage or wood boiler, and the wood won't try to heat the fossil boiler...

What it looks to me like mhearts is suggesting is a "primary/secondary" style setup, using closely spaced tees on one side of the fossil boiler, so that the wood boiler circulates its' water in a loop that the LP boiler pulls off and sends through itself and the distribution system rather than firing...

Either approach (and probably several others) would work reasonably well, though some might be more efficient than others... I think the approach I was suggesting is arguably the most efficient as it doesn't have any potential heat losses through the unused boiler, and doesn't require powering any additional pumps...

In every case, the basic control strategy is pretty much the same - intercept the call for heat coming from the thermostat(s) and send it to the wood side if that is hot enough, and the fossil side if it doesn't... The details will vary, but if you keep this basic idea in mind then it all makes sense... (Even a fancy setup like a NoFo controller will still do the same basic thing, just more elaborately)

Gooserider

Hi gooserider im having trouble understanding what your saying is there any way you could do a sketch of your approach.
I havent decided what approach I will be using yet.
At any rate I will be posting a drawing of what I want do sometime early in the new year.

Thanx Huff.

 

[Gooserider]

I finally got caught up for a bit with the hearth postings, and was able to do a bit of rough drawing with my CAD program - and created these rough drawings to show a couple of generic hookups... As I find time, I will keep working on doing other designs along the same idea - you may see these drawings fairly often...

The house load, wood boiler, and fossil boilers are identical in both drawings, the only thing that changed is the way they are connected.

I think I have the wood boiler set up right (in one of the many ways it can be done) but there is nothing special about that boiler configuration, any way of hooking up a boiler that has a supply and return coming out would work. You could also substitute the pressure side of an OWB or Garn HX - the same idea applies.

Similarly, the house load is very generic, I just slapped a DHW indirect tank and a few different styles of radiation together to give the general idea...

In the first drawing the two heat sources are in parallel, and are essentially independent of each other. Whichever one is chosen on a call for heat turns on it's pump and circulates through the house load - Again this is very generic - the pumps could also be constantly running temperature controlled, the basic idea stays the same. The flow check in each pump (which could be a discrete component instead) prevents flow through the unused circuit. (In theory it might also be possible to have both heat sources running at the same time, though this would be unusual)

The second drawing uses closely spaced tees to connect the wood boiler into the fossil boiler - house load loop. The pump for the fossil boiler (P3) will run on any call for heat (or again could be an always on pump) so it MUST be able to run without firing the fossil boiler. As I understand the theory of closely spaced tees, you could actually put them any where on the loop that is a main trunk, not just where I have them drawn. If the storage is hot P2 also runs to inject hot water into the loop through the close spaced tees. If the storage isn't hot, the boiler fires and everything works like the wood side wasn't there.

Gooserider

 

[Paso]

so that your fossil boiler won't try to heat the storage or wood boiler, and the wood won't try to heat the fossil boiler...
Gooserider

Unless of coarse you want to do it that way.

I did it as described by gooserider( what not to do ) for my own reasons warped as it may seem but works just fine and is accomplishing my goals..

If I have my OWB filled and burning, the water eventually flows thru the oil burner keeping it shut down as the water is hotter than the settings. The oil burner being warm when called into service , fires easily. (oil burners don't like cold starts) especially with non traditional oil.

When the OWB is running full throttle it has the capability to heat my storage tank, and oil burner and my Primary secondary loop.

When the fire dies in the OWB the WMO boiler heats the storage and the non firing OWB Which at this point is nothing but 275 gallons of storage.

At any given time my whole system is above 140 * with one or the other heating the water to prevent any freeze ups.

I normally fill the OWB every 12 - 14 hours have gone 24 hours before re fill.

 

[Gooserider]

so that your fossil boiler won't try to heat the storage or wood boiler, and the wood won't try to heat the fossil boiler...
Gooserider

Unless of coarse you want to do it that way.

I did it as described by gooserider( what not to do ) for my own reasons warped as it may seem but works just fine and is accomplishing my goals..

If I have my OWB filled and burning, the water eventually flows thru the oil burner keeping it shut down as the water is hotter than the settings. The oil burner being warm when called into service , fires easily. (oil burners don't like cold starts) especially with non traditional oil.

When the OWB is running full throttle it has the capability to heat my storage tank, and oil burner and my Primary secondary loop.

When the fire dies in the OWB the WMO boiler heats the storage and the non firing OWB Which at this point is nothing but 275 gallons of storage.

At any given time my whole system is above 140 * with one or the other heating the water to prevent any freeze ups.

I normally fill the OWB every 12 - 14 hours have gone 24 hours before re fill.

That works, and given that you aren't paying a lot for fuel (I assume) in either unit, it isn't a big problem. However you are presumably losing a certain amount of heat through the OWB when running on the WMO and vice versa, though probably more through the wood unit... If freeze-ups are a concern, I would still probably plumb like I drew above, but add an extra control circuit to circulate through the idle side just enough to keep things at 40-50°F so as to avoid freeze-ups, but keep the heat losses to a minimum... (this could be done with either of the two drawings)

It is a question of priorities - one of my general working assumptions (which sounds like it doesn't apply here) is that the backup fossil boiler is running on expensive fuels and thus it is important to minimize the amount of BTU's one asks it to put out...

As we keep emphasizing, every situation is different, and this needs to be taken into account - there aren't many "one size fits all" solutions.

Gooserider

 

[Paso]

I agree 100% every situation is differant.

With each setup you need to keep in mind what someone is trying to accomplish. In my case ( extremley differant) I am counting on the heat loss of the OWB to heat the area containing the oil storage.

Your drawings to the poster are excellant starting points.

If people didn't try things differently we would not have gotten to where we are today.

 

[Gooserider]

I agree 100% every situation is differant.

With each setup you need to keep in mind what someone is trying to accomplish. In my case ( extremley differant) I am counting on the heat loss of the OWB to heat the area containing the oil storage.

Your drawings to the poster are excellant starting points.

If people didn't try things differently we would not have gotten to where we are today.

OK, that was the missing piece that makes your description a bit more logical to me - if the heat loss is doing useful things, then it's far less of a concern, so your configuration makes sense... (Not that it matters a lot what I think of it, if it does what you want...)

Gooserider

 

[Paso]

I agree 100% every situation is differant.

With each setup you need to keep in mind what someone is trying to accomplish. In my case ( extremley differant) I am counting on the heat loss of the OWB to heat the area containing the oil storage.

Your drawings to the poster are excellant starting points.

If people didn't try things differently we would not have gotten to where we are today.

OK, that was the missing piece that makes your description a bit more logical to me - if the heat loss is doing useful things, then it's far less of a concern, so your configuration makes sense... (Not that it matters a lot what I think of it, if it does what you want...)

Gooserider

"Actually it does matter what you think of it "

You go out of your way to help people with there ideas and contribute a lot of " food for thought" about the design ideas people come up with so I am glad you can see some merit in in my system. It may only work for me

Thanks for all your help