OWB piping and pumps

[chumscustoms]

I ahead another thread on my wood consumption .
This thread is more about can I improve my piping, in general or just for better efficiency.

I have
Cb 6048
One pump
1 inch thermopex, buried.

It supplies two heat exchangers
One is 125btu, and one is 85btu.
The supply line runs to the 85btu exchanger, but has a tee that goes to the 125 btu.
And the same on the return .

1. Should I run into a manifold then out the exchangers seperatty.
2. Any need to insulate pipes in my basement, to help retain heat.
3. Is there any more I depth set ups that have proven to be a better piping setup.
4. Would extra storage in basement be beneficial.

Thanks in advance.
Below.is a diagram of the piping and my pump

 

[leon]

You actually have a circulator not a pump; I know, Picky, Picky.

Is your circulator in the basement? I hope it is as it
prevents it from being damaged from freezing temperatures.

Your going to be shedding a lot of heat in the first heating load before
you reach the second heating load.

The more storage you have the better so keep that in mind. Can you
install more storage in the second residence?

Even a couple of the large potable water storage tanks with a pair of copper loops
will vacuum the heat from the pex and shed it back into the water and
store the heat to be absorbed and added to the system as it calls for heat.

 

[OH_Varmntr]

I also have a CB6048. I used to run a single series loop for my loads, kind of like yours.

I can tell you that I cut my wood consumption in half this year by installing 400 gallons of unpressurized storage in my garage. I spray foamed a 400 gallon stainless steel tank, built circulator manifolds and only run water through my heat exchangers when the thermostat calls for heat. One circulator for each heat exchanger, on demand heat. I just finished the project up before this winter.

You wouldn't believe the difference it makes.

If I knew 5 years ago what I now know, I would have invested the ~$16k much differently than what I did. I would have installed a Garn or the like with atleast 1000 gallons storage and have zones like I now have. Of course I didn't find this website until I had already spent the majority of that money.

Totally different animal.

 

[OH_Varmntr]

Also, with teeing your main loop off into a secondary loop, you are losing efficiency in one loop more so than the other. I highly doubt you are seeing equal flows at each HX due to a multitude of reasons.

You should run your main line from your 6048 to heat a storage tank then draw your hot water from the storage tank to each load separately and on demand.

As far as insulating the lines inside the house, I did when I had one continuous loop running 24/7 because my basement utility room where the lines entered the house would be 80+ degrees in the winter. Sure, the heat losses were contributing to heating my house, but not where I needed it most.

Of course I installed this system at the direction of my Central Boiler dealer. Had I known any better I wouldn't have done it.

 

[maple1]

^^ Above two posts - very good info there.

I see on re-reading the first post that you did ask about storage, missed it the first time. So if you were thinking about it anyway, storage is a game changer.

OH_Varmntr, just wondering - what is your burning schedule like now? Does your OWB spend much time with no fire at all in it? There is a catch to adding storage to an OWB - the OWB might sit with no fire at times (in freezing temps), so curious how that part worked out for you. Haven't read many first hand accounts of OWB guys actually adding storage, good to see a good one.

 

[OH_Varmntr]

Thanks maple1.

As far as my burning schedule goes, it has been quite a mild winter but I haven't seen much of an increase in wood consumption during the colder spells. I've also found that loading my 6048 with two smaller loads a day rather than one big one helps keep unburned wood to a minimum in my firebox. Usually as I shovel the ash out at the end of the year I find baseball sized chunks of charred wood that were covered with ash and never burned. Burning smaller loads seems to have really helped that.

I have noticed now that it spends much more time idling. The way I have my system set up though I don't have to worry about freezing temps. I have a Taco BumbleBee Delta-T circulator on my OWB set at 20* Delta-T and it constantly feeds a 350k BTU flat-plate HX to heat my storage with due to the carbon steel jacket of my OWB. It usually runs about 42 watts at 10gpm which is right where I designed that loop for. Those numbers are merely from the display of the circulator, nothing has been verified and I have yet to take readings of supply and return temps from my OWB but given the circulator is not running full speed I'm relying on it to do its job. This way I always have water circulating through my water jacket on my OWB. I believe I am pushing the useable flow-limits of my 1" Thermopex though as far as BTU transfer goes.

I drew up a controls system to only run the OWB circulator based on the demand of the storage tank but didn't want the complexity of it at this time. I wanted to observe how my current design operates this burning season and so far I'm very pleased. If I end up doing another big change I'll be tearing out my relay-based controls and going full PLC control.

My storage tank and zone heating system has zero carbon steel which is why I separated it from the OWB loop. I still have to insulate the circulator manifolds and lines inside the garage which would only further decrease unwanted losses.

I have really increased the efficiency of my unit with my storage and zoning setup but I realize it is nowhere near what I could have. So far I'm extremely pleased with the hybrid system I'm using but like I said in above posts, I would love to tear my OWB out and use the space in my garage for a Garn with at least 1000 gallons of storage. More money spent on adding insulation in some key areas and I'll be one happy camper.

 

[chumscustoms]

Thank you.

I was wondering about b that and you answered many questions.

So I would need a pump from cb to storage and then a pump from storage to cb.

Then off of storage I would need a pump for each zone/hx. Which would be tied into to elctrical circuit of the blower motor on each hx.

This is intriguing and I will throw this around.
Good info.
Thanks.

Some told mebthat the inefficiency of a cb6048 would not benefit from a storage due to its inefficient burn.

 

[OH_Varmntr]

To remove any issues with water level differences you would need to separate the OWB from the storage tank via a flat plate heat exchanger, or get a storage tank with internal copper coils. The OWB water is circulated through the internal coils to transfer BTUs into the storage water.

Then you can run a circulator for each heat exchanger in your ductwork off of the topside of the storage tank, and return the water into the bottom of your storage tank.

There are several very helpful illustrations available to show this if you search Google for hydronic water heating.

 

[OH_Varmntr]

As far as the inefficient burn statement, they are referring to how many BTUs produced from burning wood are actually transferred into the water in the surrounding water jacket.

It's true, these old smoke dinosaurs lose a lot of useful BTUs out of the flue, but the more water you have available for storage, the BTUs can be stored.

 

[OH_Varmntr]

Here's a great thread with a link. You can read for hours.

https://www.hearth.com/talk/threads/biomass-hydronics-training-pdf.137252/