Value Engineering with added Storage

[SIERRADMAX]

What's a "rough cost" of adding storage to a gassifier aside from the cost of the tanks?

I'm weighing the option of buying a 1000 gallon pressurized tank for use with my econoburn 100. However, with my homes heat loss calculated at 50,000 BTU/Hr, if I am correct, an 8 hour burn should yield 8 hours of useable hot water with a delta T of 50 degrees (190-140)? Effectively cutting my wood consumption in half.

1000 gallons @ 50 degree Delta T = approx. 400,000 BTU's
400,000 BTU / 50,000 = approx. 8 hrs.

To charge: 50,000 BTU (net output after house load) would take 8 hrs. to charge to 400,000 BTU

Obviously I would see better results in warmer weather.

Any thoughts?

 

[ihookem]

Well, as for me we figured 200 bucks?? for labor and 100 for material was our guess. I have my plumber buddy hook my stuff up so prices may vary cause I give him this green paper tha keeps him coming back. I can't seem to find a decent storage tank though.

 

[avc8130]

1000 gallons of storage will need ~$1000 in expansion tanks...unless you go with an open storage system.

You may need another pump ~$100.

Figure $200-$500 for pipes, valves, fittings, etc.

You will NOT burn 1/2 the wood. That math just doesn't work. Each piece of wood you put in has a set amount of BTUs it can give.

1 burn to recharge 1000 gallons of storage from 140-190 will take more than 1 load of wood.

ac

 

[SIERRADMAX]

so, maybe a 1/3 less in wood consumption?

 

[avc8130]

so, maybe a 1/3 less in wood consumption?

The only change in wood consumption will be in system efficiency. If you can run your system more efficient with storage, you will save that wood.

The overall opinion is that storage is more about convenience than wood savings.

ac

 

[NE WOOD BURNER]

with 1000 gallons of storage. how much expansion volume would be needed? Vertically where would the expansion be placed? above or below the storage tanks?

 

[avc8130]

with 1000 gallons of storage. how much expansion volume would be needed? Vertically where would the expansion be placed? above or below the storage tanks?

Depends. Bladder or no?

 

[NE WOOD BURNER]

Bladder appears to be recomended.

 

[arngnick]

I recently went through all the same questions when I purchased my new boiler and storage. If your stove idles alot it may save some wood consumption, the biggest benefit I see with mine is the fact that the storage will carry you between burnings. Do you keep your stove burning all the time or does it go out and need relit? Here is a link that may help with some of your questions...

http://hillsideenergy.com/thermal_storage.htm

https://www.hearth.com/talk/threads/expansion-tank-volume.51241/#post-51241

 

[avc8130]

Bladder appears to be recomended.

For 1000 gallons I think you will need 2 of these:

http://www.pexsupply.com/Amtrol-118-155-SX-160V-Extrol-Expansion-Tank-86-Gallon-Volume-7370000-p

ac

 

[henfruit]

I only use one and it works fine.

 

[avc8130]

I only use one and it works fine.

What temp range do you run?

What pressure gain do you see?

 

[stee6043]

For an existing indoor boiler I don't think you'll ever get a reasonable ROI on storage purely based on wood consumption reduction. As stated above it's primary purpose is convenience, with a slight added benefit of increased efficiency in many cases.

You're not running a 200k btu boiler so your efficiency gains will likely not be huge.

 

[maple1]

with 1000 gallons of storage. how much expansion volume would be needed? Vertically where would the expansion be placed? above or below the storage tanks?

I've got two stacked horizontal 330 gallon tanks for storage, and a 110 gallon propane tank as a simple non-bladder expansion tank. It sits upright on the floor beside the storage tanks. I run between 8psi cold & 15psi hot. I wasn't sure this would work, but so far so good. My cost for all three tanks was $780. You won't really see much of a decrease in wood consumption just by adding storage - unless maybe you are comparing to a boiler that spends a lot of its time idling, in which case storage would take the idling out of the equation.

 

[peakbagger]

For me it came down to what would fit in the basement and what I could install and move myself due to lack of assistants. I have an unpressurized American Solartechnics tank. It costs more than a home built pressurized system (based on a non code alteration to an old propane tank) and its legal in all states. I picked it up, hauled it home, carried it down the stairs and installed it myself. It takes up less space as its square and I built a hanging set of shelves on top of it so there isnt a lot of wasted space. With 550 gallons and conventional radiators, I reallize that its only good for one day during cold weather and about 3 days in shoulder season. I have oil backup so if I am gone, oil keeps the house from freezing. Sure if I was building a house and had access to a code tank, I would go bigger and if my surplus PV generation copntinues to climb I may be looking for some electric baseboard to replace the oil.

If my tank floods the basement, I can claim it on insurance, I am not so sure a non code altered vessel would be treated the same by an insurance company.

 

[stee6043]

For me it came down to what would fit in the basement and what I could install and move myself due to lack of assistants. I have an unpressurized American Solartechnics tank. It costs more than a home built pressurized system (based on a non code alteration to an old propane tank) and its legal in all states. I picked it up, hauled it home, carried it down the stairs and installed it myself. It takes up less space as its square and I built a hanging set of shelves on top of it so there isnt a lot of wasted space. With 550 gallons and conventional radiators, I reallize that its only good for one day during cold weather and about 3 days in shoulder season. I have oil backup so if I am gone, oil keeps the house from freezing. Sure if I was building a house and had access to a code tank, I would go bigger and if my surplus PV generation copntinues to climb I may be looking for some electric baseboard to replace the oil.

If my tank floods the basement, I can claim it on insurance, I am not so sure a non code altered vessel would be treated the same by an insurance company.

Almost any tank can be "legal in all states" when they sit on the manufacturers floor. How they are installed, unfortunately for the DIYer, is equally as important for their ability to meet code. Assuming your installation is cosher based on the fact that your tank was code compliant when it was built and is "approved for use in a hyrdronic system" is a bad assumption to make.

To that end, your home owners policy may or may not cover damage for a failure in this type of system. Assuming your covered for a tank failure is yet another ill advised assumption to make. If you don't have it in writing or specifically stated on a rider it may well be excluded. Especially if any part of your system is not up to code, properly permitted and final inspection approved.

 

[tmudd]

In my case, the cost of storage came to adding a loading valve $ 595, two five hundred gallon propane tanks, $ 50 each,I needed to clean them, welding supplies to connect the two tanks, $140 and 20' of 1 1/2" copper pipe and fittings $200(ouch ). an sx 160 expansion tank added enough expansion to what I already had. $ 440. In my installation, the two tanks were connected with 6- 6" cut holes in the top and bottom of the two horizontally opposed stacked tanks. then welded a skirt around both tanks connecting them to each other with 5/16 plate, on the ends a slice of 10" pipe cut in halve finished off the ends.. I opted to put 3 ports into the top and bottom of the tanks with weldolets and then made a manifold on top of the tank (supply)and bottom of the tank(return).At the time I was really hung up on good stratification. My fellow boiler mates on this site pretty much said anything would work, But you know how you get focused on one detail. In the end the system works super. I have a frohling 50 for a wood boiler. In mid missouri, our temperature has been in the teens and 20 for the last month. I can consistently charge the tanks from 125 top and bottom to 180 top and bottom on one 3 hr burn. the unit holds 6-7 cu ft of wood. The key points in my mind from information gleaned on this site is to size the piping correctly so you can transfer the amount of heat your boiler can crank out to storage and the load you need to service. My boiler is 1 1/2" supply supplying 3- 1 1/2" ports to storage which effectively slows down the flow through you tanks. My load to the house 100' away is serviced by 1 1/4" undergropund insulated pex. This sizing allows you to load storage and supply loads simultaneously. I can supply load to pex radiant underfloor for my first level and load storage in this 3 hr window. The frohling has amazing horsepower.to transfer btu to water unlike my first gassifier. I agree that the biggest advantage between storage and non storage is convenience. the computer monitor on the boiler keeps track of how many hours the unit is burning by keeping count of fan time. When the burn burns out the fan goes off, and how many hours the unit is in slumber. It does not slumber ever. For me storage was a game changer in my system no matter what the cost. For the most part I have been operating on one fire a day through most of the winter, It really boils down(no pun intended) to what your time is worth.

To the best of boilermen,
TLM

 

[SIERRADMAX]

deposit placed onon two 500 gallon tanks. Looks like I'll have a fun summer project!

 

[arngnick]

You mean weekend project