two questions expansion tank sizing and propane storage tank pictures?

[2.beans]

im adding 1000 gallons of storage aprox. 200 gallons in house/shop ect. i was wondering what size expansion tank i would need. [worst case]. secondly does any one have any pictures of propane tanks hooked up for storage and what they did to tap the tanks im using 2 500s. thanks

 

[Bob Rohr]

my sizer only goes to 1000 gallons... try this I'll bet you will need close to 100 gallons of expansion if you plan on 55F to 190f temperature swing with that volume.

www.hvacwebtech.com/watertools.htm

LP tanks have a bunch of connection points, Usually 4 or more on top, and most have a bottom drain tap. If not drop a dip tube in one of the top holes to send the hottest fluid down there first. Pipe it so you don't have to wait till all that volume gets to temperature, before you start covering the heat loads. Possibly pipe it so the tanks could load separately?

hr

 

[jebatty]

Water expansion from 32 -200 is about 3.5%; figure a little more for safety. If you use a bladder-type pre-pressurized expansion tank, you need to look at the acceptance volume of the tank. This probably means about a 90 gal bladder expansion tank to handle 1000 gal of storage.

 

[2.beans]

thanks for the input. i added four more inlets/outlets to the tanks, 2 dip tubes to the bottom, and two off the top. i was going to put the charge from my seton 200 to the top and the supply to the house off the top. then all the cold returns to the bottom. the tanks will be hooked in parallel with equal line in and out to both tanks. is this not the way to get the best stratification? or can i just mix the water and have 180 degress throughout the tanks? im able to hook this up any other way. ive seen some have a pipe going into the the tank with a holes drilled in it. im sure theres more than one way to do this. any and all input is good to me. thanks

 

[Nofossil]

There's some dissent on this point, but I believe that you want as much stratification as you can get, to the extent that if I had two tanks I'd plumb them in series, bottom to top.

When you're charging, you want to put hot water in the top and take cold water out the bottom, with as little mixing as possible. If you heat a tank at 100 halfway to 180, you're much better off if the top half is at 180 and the bottom half is still at 100, than if the whole tank is at 140.

Ideally, you'd draw 100 degree water out the bottom and add 180 degree water in the top until the whole tank was at 180. Same in reverse for withdrawing heat - much better if the outlet stays at 180 until the whole tank is depleted.

 

[tuolumne]

I have 2 500 gallon propane tanks with a total system volumne of around 200 gallons. I used an 86 gallon expansion tank... http://www.plumbersurplus.com/Prod/Amtrol-SX-160V-SX-EXTROL-Expansion-Tank-86-Gallon-(118-155)/7950/Cat/32 ....which I found locally quite a bit cheaper. I drilled 4 new holes for tank circulation with a holesaw and bar oil (about 5 minutes each)...don't let the piece fall in the tank. As soon as I can get my tractor down to the basement again (mud season) to lift the tanks, they will be stacked one atop the other.

 

[2.beans]

There's some dissent on this point, but I believe that you want as much stratification as you can get, to the extent that if I had two tanks I'd plumb them in series, bottom to top.

When you're charging, you want to put hot water in the top and take cold water out the bottom, with as little mixing as possible. If you heat a tank at 100 halfway to 180, you're much better off if the top half is at 180 and the bottom half is still at 100, than if the whole tank is at 140.

Ideally, you'd draw 100 degree water out the bottom and add 180 degree water in the top until the whole tank was at 180. Same in reverse for withdrawing heat - much better if the outlet stays at 180 until the whole tank is depleted.

nofossil so the way i plan to do it is correct? charge from the boiler to the top and return to the boiler from the bottom [thru the dip tubes] , feed to the house off the top and cold return from the house to the bottom thru the dip tube? thanks

 

[2.beans]

I have 2 500 gallon propane tanks with a total system volumne of around 200 gallons. I used an 86 gallon expansion tank... http://www.plumbersurplus.com/Prod/Amtrol-SX-160V-SX-EXTROL-Expansion-Tank-86-Gallon-(118-155)/7950/Cat/32 ....which I found locally quite a bit cheaper. I drilled 4 new holes for tank circulation with a holesaw and bar oil (about 5 minutes each)...don't let the piece fall in the tank. As soon as I can get my tractor down to the basement again (mud season) to lift the tanks, they will be stacked one atop the other.

i drilled all my holes with a torch. cutting very small amounts at a time into the tank filled with water then drained and rinsed it. i was going to stack the tanks but i didnt like the idea of having all that weight in one spot. all together it should be around 10000 pounds filled. and lifting one empty tank in my basement would be really hard to do, plus youd want a really strong stand to hold the top tank. thanks

 

[Nofossil]

nofossil so the way i plan to do it is correct? charge from the boiler to the top and return to the boiler from the bottom [thru the dip tubes] , feed to the house off the top and cold return from the house to the bottom thru the dip tube? thanks

That's the way I'd do it. I'd also spend a little time trying to figure out how to introduce water into the tank with minimum turbulence and mixing. Some folks have posted some good ideas on this topic.

I should point out that there are folks who argue for minimum stratification / maximum mixing. I haven't been able to figure out why that would be desirable, but just because I don't understand it doesn't mean that they're wrong ;-)

 

[wheeler]

expansion tank size should be a 100 gallon.Be caefull on your underground pipe selection.it is easy to look at price instead of quality -it will make a big difference on would consumption.i would listen to your locall heating professional.

 

[2.beans]

how did YOU figure out what size expansion tank? you must be LOVING cutting wood every weekend or do have someone cut your wood for you? you should have joined on april fools day that would have been CLASSIC. and for price and quality i feel i did on my boiler, good advice. thanks for all your positive feed back and your speedy service.

 

[jebatty]

If you Google water expansion, you will find the info. Approximate water expansion from 32 - 200 is 3.5%, use 4% or more for a error/safety/system factor. Expansion of 1000 gallons = 40. Be sure to include system water volume in the calculation, so a 1000 gallon tank will have extra system gallons. Then to size a bladder expansion tank, look at the tank specs to find acceptance volume, and size the tank to take the needed expansion.

 

[trehugr]

My question is where to place the expansion tank. Mine will be a 86 gal tank for 750 callon propane tank(s) storage in the basement. Backup oil boiler in basement. EKO in shed 75 feet from house. Could I put the expansion tank in the shed with the wood boiler ?

 

[Bob Rohr]

The data to correctly size that tank would be temperature at start, max temp., fluid type, fill pressure and relief pressure

For example 50-190F, plain water, fill pressure 12psi, and 30psi relief. That would take 132 gallons of expansion tank.

Doubtful you will find a single, non ASME tank that large. Two 62 gallon 110V B&G;tanks would do it. Don't undersize or you WILL pop the pressure relief valve. That's a lot of volume.

Physically the tank can be located anywhere. But connect it to the system just before the boiler circ pump. This establishes the PONC point of no pressure change. All circs pump away from this point, and it is also a great spot for your air elimination device. For that system a simple, inexpensive cast iron air scoop works well.

Prpbably pipe to that tank (s) with 1" pipe.

hr

 

[wheeler]

It sounds like you guys should have bought a classic wood boiler!seems like alot of work and by the time your done you end up with a classic.By the time you by the seton or other gasafied wood boiler-hook it up to your heating system-find out that it can't keep up to the heating load or hitting the dump zone all the time-then go out and buy two 500 gallon gas tanks so you have enough storage to be able to heat your house and then re-pipe your boiler again and tanks seems like alot of work.I have a 1800sg house -classic wood boiler no 1000 gallon lp tanks in my basement-and burn 8 cords of wood this winter for heat and hot water.And to the guy that asked if i cut my own wood or not-this year i was behind the eight ball with time and i planned on cutting it myself but i had to re-pipe a seton wood boiler so it might be able to heat this guys house-I told him i could not get to it that weekend because i had to cut wood-He said i'll help you re-do my seton wood and then i will help you do wood.needless to say i got the better end of the deal-i got my wood cut and his seton wood boiler still dosn't heat his house.The good news is now i get to go over their and install two 500 gallon storage tanks so it can work.SENTON AND HATING IT!

 

[2.beans]

Sorry about the thread hijack - the last poster (Classic & Loving It aka Pinnochio Plumbing & Heating) should start his own thread on "Classic Wood Boilers." Sorry he got off topic, he's just our local small town plumber with nothing better to do.

By the way - 8 cords of wood for an 1800 sq. foot house? Ummm, is that good? Jackass.

 

[EForest]

It sounds like you guys should have bought a classic wood boiler!seems like alot of work and by the time your done you end up with a classic.By the time you by the seton or other gasafied wood boiler-hook it up to your heating system-find out that it can't keep up to the heating load or hitting the dump zone all the time-then go out and buy two 500 gallon gas tanks so you have enough storage to be able to heat your house and then re-pipe your boiler again and tanks seems like alot of work.I have a 1800sg house -classic wood boiler no 1000 gallon lp tanks in my basement-and burn 8 cords of wood this winter for heat and hot water.And to the guy that asked if i cut my own wood or not-this year i was behind the eight ball with time and i planned on cutting it myself but i had to re-pipe a seton wood boiler so it might be able to heat this guys house-I told him i could not get to it that weekend because i had to cut wood-He said i'll help you re-do my seton wood and then i will help you do wood.needless to say i got the better end of the deal-i got my wood cut and his seton wood boiler still dosn't heat his house.The good news is now i get to go over their and install two 500 gallon storage tanks so it can work.SENTON AND HATING IT!

Is the Classic you own the Classic by Central OWB?
OWB have a bad rap these days so please share you experience with us. I'd love to hear a Cinderella story related to an OWB for a change. There are a few OWB in my neighborhood that ruin it for the rest.

 

[wheeler]

I Have had really good Luck With my Central OWB!It dosn't smoke any more than a regular wood stove in somebodys house.forty degree's out today filled the Boiler this mourning at seven got home tonight at seven but one log in the boiler that was about a foot round and that while last me till tommorow at seven,the boiler was still 3/4 of the way full.Very little heat call today but still have a wife and two kids at home doing laundry showers and cleaning.Smoke is never an a promblem,Boiler i beleive is sized right for the house.My Boiler is only thirty feet from my house never a promblem with smoke.Don't get me wrong i have seen plenty of smoke coming out of central boilers-just not mine.I have personally installed at least twenty of them and all the customers like them.It's not a cinderlia story.I'm Happy.

 

[Bob Rohr]

A cord of mixed woods contains about 14,000,000, yes 14 million btus. 8 cords for an 1800 sq ft home seems awful high. Either a very leaky home or a stove running 30% or less efficiency. Or both?

hr

 

[wheeler]

Dear master of sparks-My heat loss is right aound 70,000 btu at 20 Degree's below zero-so that would be around 1,800,000 a day at 20 below.It hasn't been 20 below this winter but has been cold up here in the north east.I Stared my boiler at the begining of septmber for a little heat and hot water and Still Running now.How many cords of wood did you go threw? When I Heated my House with a wood stove I would go threw at least threw 5-6 cords and one room in my house was 90 and the others where 60.I don't Know But 8 cords didn't seam bad for 8 months worth of burning.What should have burnt 1 or 2 cords?

 

[Bob Rohr]

Yeah, 5 or six would sound more in the ball park. Shouldn't you be using the same, or less than when the fire was inside the home? If not the extra cords are being turned into emissions, combustion and distribution losses.

70,000 for 1800 square feet is over 35 btu/ square foot. Just seems a bit high, but not knowing your home maybe that is about right.

Sounds like a typical winter of 20 belows may cost you 10 or 12 cords?

hr

 

[ugenetoo]

glad im not in that neiborhood!!

 

[wheeler]

No I beleive I would be using more wood.I am now heating my whole house instead of just one room, and also heating my domestic hot water a wife and two kids.I also work outdoors 90% of the time and we keep the T stat at 74 Degrees.And by the way to guy that says he wouldn't want to be my neighbor-I probably wouldn't want to be yours either,also i can't see a neighbor from my house.My OWB Dosn't Smoke any More Than a wood stove in a chimney.My OWB is about 30' away from the house never a smoke issue unless I But in green pine from a tree limb tha came down.