One step closer ...

Today was a productive day - picked up a mass storage / buffer tank for the Heat Exchanger / reclamation unit I am building for the Pellet Stove here:



It's called a Boiler Buddy, model BB-30, essentially it is a 30 Gal. storage tank w/ Hot & Cold input on either side of the tank: 1 side for the Boiler, 1 side for the Heat distribution loop.

Current plans are to use a thermal oil exchange loop off the Pellet Stove -> to a Heat Exchange plate mounted inside a small water tank in the living area to heat the water: the smaller tank will feed this one downstairs, and in-turn run a Modine radiator unit underneath the house in the basement/crawl space area.

I'm thinking of using a Beer Keg as the small tank upstairs. ( I'm sure the wife will be thrilled. )

I am still drawing plans for the thermal oil loop / sourcing materials, but have found a local company that does custom metal fabrication for reasonable prices, they will be cutting & bending the stainless sheets / pipes that will be used in the project.

I will update the thread as the project progresses, here goes the Beer Budget, again..

 

Me too! But I just used the watch thread button.

 

You fellas are high tech...I will just read the post when I am online!!

 

Sounds like a great project.

You should be able to reclaim a lot of heat with that setup.

 

Cool ! Welcome All.

I am going to get some pics of the Hearth area behind the stove, and am planning to do a cardboard mock-up or two for sizing - will post pics later this evening.

In the first phase of this project, the goal is very limited: to simply reclaim enough heat to run a Modine Radiator unit (or equivalent) in the downstairs basement/crawlspace to prevent pipe freeze.

Goal is to get the crawlspace temps. to 50F or above, the basement/crawlspace is a considerable 'heat sink' currently. Any use of additional bonus heat will be considered later.

For the primary Pump, I am strongly considering the:

Taco HEC-2 Bumble Bee Variable Speed Circulator with Integral Flow Check

This appears to be the 'easiest' pump for dummies like me w/ little to no boiler system knowledge - you set the target temps., it will figure out the pump curve / flow rate for you. Sounds great on paper, anyways.

--
The Boiler Buddy BB-30 was advertised by a kind gentleman on CL, who had purchased it 2+ years ago to use w/ a Modified Condensor (aka "Mod Con") Gas Boiler he purchased: it was in-use for a few months before he removed from service / simplified his design.

Cost so far into the project: $65.00 for the BB-30 and a bunch of fittings thrown in, $20.00 in fuel to get it.

It's missing the top air vent stack, but that's ok - I plan on using a separate Expansion Tank w/ vent - that port, and the drain port @ the bottom of the tank may be a way for me to get some copper tubing in the tank to add a pre-heat loop for the electric Hot water heater in the future.

* If anyone reading has real-life experience, or other thoughts about using the Taco HEC-2 Bumble Bee Circulator pump - I'd appreciate hearing them, Thanks.

 

Sorry guys - stepped out yesterday, Boss cleaned & started stove.. Will be busy clearing snow & traveling, pics tomorrow or Monday.

 

UPDATE:

Ok, got some pics today to show everyone what I have to work with here.

Ladies and Gents, guys and gals - please allow me to introduce the Ecoteck Francesca stove:




The current vent setup is all 3" DuraVent Pellet pipe:

1) Appliance Adapter attached to a slip coupling on the back of the Exhaust outlet assembly,
2) A 12" inch Pipe section,
3) A 90 degree Elbow,
4) A 12" inch Pipe section,
5) A slip coupling, that is attached to the top Flue block plate.

This setup allows me to quickly detach the "L" of pipe/elbow/pipe from the top flue plate, and back appliance adapter for easy cleaning.

As there is no clean out "T" in the setup, this section of pipe needs to be cleaned every 25 bags burned.




The stove seems to be burning very well: when I pulled the "L" section to clean it today, after 22 bags burned, there was only a coating of black soot in the pipe, maybe 1/8 cup total.

I'm sure there is some more in the exhaust housing / blower chamber, but it's frosty here, didn't have the time to do a full deep clean. (Probably another 1/8 - 1/4 cup in the stove, based on past cleanings.)


In case anyone is interested, here is where the K2 probe wire sits at the Heat Exchanger outlet:




The firebox on fireplace is not large, and trapezoidal shaped: 36" across at the front opening, 29" at the back wall, sloped forward, which is a PITA dimension-wise.

Whatever I place behind the stove has to be compact enough to allow me to access it, but large enough to hold a sufficient volume of exchange loop pipe to allow heat transfer. I found a box here that seemed to work well, it was compact enough to fit behind the stove without any problems, and allowed access from either side / room for piping, etc.



Right now, for ease of calculating, the dimensions of the reclaimer box will be 12" (w) x 12" (h) x 18" (l). These dimensions will also allow me to incorporate sections of DuraVent pipe to allow hookup & removal.

--

Thermal Oil (aka: Heat Transfer Oil) vs. Water exchange loop:

A primary design goal is to keep the unit (External) from the existing stove - I don't want to break what is currently working here.

Up to a few days ago, I really wasn't a fan of having a water loop running in back of the stove: the primary concern being "what if the loop leaks", etc.

Because of this, early on I had decided to use a closed oil-loop, with stainless line inside the reclaimer unit, going to a heat transfer plate to heat a small tank of water in the living room, which in-turn would feed the BB-30 tank downstairs.

This may not be feasible though, the problem is Heat transfer rate, and pressure needed to run the oil loop.

--

As I have been researching the materials / requirements for the oil loop, I am finding it would take a huge amount of BTUs to properly heat the oil, and that oil would have to be run under pressure constantly: 25 - 40 PSI.

So I am left with a decision: which is the lesser of two evils, having a potential water loop issue, or a potential oil issue, under higher pressure?

As I mentioned above, I will be using the Taco Bumble Bee circulator pump on this (primary) loop, because it has ability to properly vary flow rate, etc. based on temperature settings.

I still need to calculate the amount of loop I can place in the reclaim box with each (Oil or Water), but right now, because I will be using this pump, I am leaning towards installing a simple water loop to start.

--

Project purchase #2:

Another kind gentleman on CL listed a bunch of plumbing fittings, etc. left over from a previous boiler project / was 'cleaning out his basement' for $30.00
This included (7) new 3/4" ball valve fittings, and about another 50-75 dollars worth of sweat fittings, also new. I still haven't gone through all the stuff in the box yet. I'll try to get a pic or two up tomorrow.

Goals this week:

Build a proper mock-up of the box/container needed, calculate amount of pipe that will fit in the container / calculate volume of water (or oil) the pipe will hold,

Finish procuring the remaining reducer adapters/fittings needed -> to 3/4", to be able to close all ports on the BB-30 tank, to do a pressure test.


Will update in a day or two..

 

Pic of project purchase #2, as posted on CL:

 

This is a sweet little project you have going here. It will be very interesting to see how you make out. I like the look of that stove you have a well. It's a nice clean looking unit considering what you told me about it's condition when you got it!

 

Kudos to you

 

You will exchange the heat three times?
three loops/ two pumps?

 

Howdy BAN83 & ivanhoe, nice to see you here. Greetings to our friends in the North Country, hope you are staying warm up there. (It's gotten cold down here.)..

Hi Tim, Yes - that was the original plan, but the issues I'm now facing with that design w/ using a closed Oil thermal loop, are complexity, and cost.

Originally I had hoped a simple closed loop would transfer a sufficient volume of oil without having to resort to introducing a wet sump / pump system, but that unfortunately will not work, it would take -forever- to heat the water.

For a closed oil loop system, I will need:

Mass volume of oil, a storage (sump) vessel, an oil pump, heat transfer plate / loop, and a (custom) controller, to properly meter flow rate through the loop:

Oil Thermal Loop:
--
Thermal transfer oil: $250.00 / 5 Gallon pail (Paratherm MR Heat Transfer fluid) - Food Grade
Heat transfer plate: $125 - $150 (if not custom-made here),
(2) 50 ft. stainless steel line loops: $50 each / $100 for both,
Variable pressure rate external Oil pump: $120.00
Sump Vessel, 2.5 Gallon, fittings, etc. $100.00 (Est.)
--
Total cost: $570 - $650 (Again, Est.)

Vs. Water loop:
--
50 ft. 1/2" Type L refrigeration pipe: $85 - 100.00 (or) 3/4" coil $120.00 (Est.)
Taco Bumble Bee Circulator Pump: $185.00 (which I would need in either system)
--
Total cost: $305.00 - $325.00

* To do a proper oil-loop system, right now the #'s are looking at (2x) the price of direct Water loop system.

The secondary issue is having mass storage in the Living area - I don't think the Boss will be too thrilled w/ that.

And there is also having a (oil) pump system within the Living area as well - I may as well start moving my belongings out to the woodshed, immediately.

I have a limited thermal range to work with on the small stove here. When up to operating temp., internal Stack temp @ the stove exit is 290-305 F, I estimate I have 80 - 90 F worth of heat to recapture from the stack vent for heating / storage. * It may be more, I won't know until I run testing on a working loop to see heat capture / time to warm up a fixed volume of water.


I'll try to do some Visio 'magic' and post up a proposed diagram of the system design tonight or tomorrow.

 

Usually space is not in your favor but with a open basement opens a lot of possibilities but again not in your favor
You might need a behind closed curtain gizmo and be princess approved

 

I sometimes feel like a wizard, but of Oz is a tall order.. Yes, space is limited here.

And there is the 'MacGuyver' factor also - insomuch as I would prefer to keep costs down / 'experiment', I have to be cognizant this will be installed in the main Living space / it really needs to be to code, w/ adequate safety controls built into the install.. I can't be screwing around too much here.

For example, if I go with a water loop, I will need to add a moisture / water sensor to the reclaimer box, an electronically activated gate / purge valve off the upper tank. and appropriate controls to dump water out of the system -> drain the water out of the upper loop (in the living space) above the tank -> shutdown any/all circulator pumps, in the event of a leak. Flooding our stove from the back exhaust port really isn't an option here.

I haven't used Visio in awhile, it's fighting me every turn, and the 'simple' diagram is becoming more complex by the minute - what I really need is a shot of hard liquor, a pen, and a bar napkin to write down / figure all this shtuff out properly.

I'll get there, but it may be another day or two before I post it.

 

Crawl space can be insulated.
Grab the heat of exhaust pipe via a slow fan directed into basement.
Dig the crawl space for the gizmo you plan to do.
Even use sun power for the mentioned water tank.
Lots of choices.....

 

With my luck, I'll end up 200 Nautical Miles off the South Coast of Australia.

 

Yesssss, gotta keep the boss happy.

My having a stove in nearly every available corner was pushing the limits of civility A LOT
Buttttttt, the nearly non existent heating cost sort of canceled out the issue

Now, with the two extra Whits sitting in the basement taking shape the Corner thing is being verbalized again.

NO MORE STOVES.

I will wait until the other half is away for a day and sneak one in and drape a tasteful table cloth over it, then play stupid. Huh, whaaaaaaat, oh geeeeee, OMG haven't a clue