Opinions of Two 1000 Gal Propane Storage Tanks for new DIY build

[landrand]

I recently bought a new never used Tarm Solo Plus 60 (60KW, 198,000 BTU) wood boiler. My next objective is to build a DIY pressurized storage system with propane tanks. I found a couple of used 1000 gallon propane tanks (for $750 each) that appear to be in very good shape. Attached are pictures of one of the tanks. I plan to heat a couple of internal insulated partitions (around 2500 sq feet) within a 50'x100'x16' eaves steel building used as my retirement workshop. I have a used propane boiler that can be used as a secondary unit. The preferred temperature would be around 50 deg F in the shop. I live in Northern Michigan and the winter temps are extreme.

Assuming I have room for two tanks and could either stand the tanks upright vertical or perhaps horizontal, I have a couple of questions.

1. I've been reading and researching wood boilers for the last couple of weeks and one take away is that more storage is better than less. Would 2000 gallons of storage be considered "too much" for this boiler and application? Would I be better of with just one 1000 gal tank or perhaps two 500 gal tanks?

2. What's your opinion of the tank shown in the picture? Does it look suitable for heat storage? Note that the tanks are already plumbed with pipes on both ends of the tank.

3. I don't know what heat emitters I would use yet. In-floor piping is probably not doable unless it was possible to do pex in gypcrete on top of the existing 5" cement floor. I would imagine this to be very expensive though.

Note: If I can't stand the two tanks vertical, I could weld together a heavy duty platform and have the tanks stacked over each other in a horizontal position.

 

[sardo_67]

if you have the room and means to move/modify them then go for it! you could always prep and pour a thick concrete pad on the outside of your building, put the tanks on that and box it in with 12' walls for insulation, just make sure the pad/footings are set up for the correct amount of weight. water and steel put together i would guess at almost 20,000lbs in a small area

standing them up vertically is going to work best as you can really separate the hot and cold water that way.

HS Tarm is a good company and they still fully support even their original boilers like mine that was made in 1979, i really would suggest getting parts from Tarm and their loading unit. basically a mixing valve that adjusts your hot water storage and return water so it doesn't cool the tanks off too fast (how it was explained to me).

if you google "dragons breath heaters" you'll be bought to a CT company that sells water to air head exchanges that will work perfect for you application, only way to put pex in would be to demo the floor and redo it all.

also what is your budget on all of this, what do you really expect to get from this set up?

 

[maple1]

Storage should ideally go in a heated space. Where standby heat loss (there will be some no matter how well you insulate them) would all go to the heated space. So it might come down to how much you can fit into your space. I wouldn't likely say 2000 would be too much - it would give you more burning flexibility. But if the tanks can't go in a heated space - then I would try to limit how much I have. The more gallons you put in an unheated space, the more heat it will lose.

I would use those tanks yes but would likely stack them horizontally. Mainly because it looks like an easier thing to do. If I was doing it, anyway. There are also top tappings on it - is there a bottom one? My small stacked 330's stratify well, return water stays on the bottom. So going vertical isn't necessarily a be-all end-all thing. Horizontal would also spread out your weight on your floor.

 

[BoiledOver]

2,000 gallons is looking very good for your boiler output and intended use. People will state all day long to stand them on end for stratification results. In my case, I have two 500 gallon tanks stacked horizontally with 5 temp sensors equally distributed from top to bottom. I can assure you that there is excellent stratification in these tanks. It will be your choice how to arrange them depending on desired footprint and ceiling clearance.

A note about your pictured tank. If mounted horizontally, you will get better results if you do not use the end taps as it is now. I tapped the bottom at 2
inches off of the bottom to reduce any sediment from coming back to the boiler. The top tap is at the highest point of the tank. The y strainer has shown nothing after several seasons so it seems to have worked. Honestly though, I do not believe there is much junk in the system at all.

The mating system in this case is at 3 points across, end, middle and opposite end using custom cut sections from a 100 pound propane tank. The 500 gallon tanks came with 6 feet per unit so I took four from the upper tank and welded them to the bottom tank. The 1,000 gallons total sits directly on the 4" slab. The 3 mating points has supported the upper tank without any signs of failure for 5 years.

My reasoning for stacking horizontal was dictated by ceiling clearance. I did the whole job solo in a shop that has 8'-11" ceiling and used no power equipment. It was a wrestling match for sure.

 

[landrand]

Currently, my 50'x100' steel building is not insulated. The building is not usable as a workshop during the summer months as the sun light hitting the metal roof and sides turns the building into an oven. In winter, I have to deal with very cold temps if I want to do any projects in the building. Since insulating the whole building would be very expensive, I plan to build a couple of insulated partitions inside and only heat those areas as workshop areas. In addition, I can use the roof's of the inside partitions as storage space rather than on the main floor. Here's a couple pics of the inside of the building to give you an idea of what I'm working with.

For a hobby, I have a sawmill, backhoe, and large forklift. Lifting the 1000 gal tanks shouldn't be an issue with my equipment. The wood slabs from my sawmill operation would easily produce enough wood to feed the wood boiler. I also can weld so I shouldn't have any issue in modifying the tanks or building a horizontal platform.

 

[NateB]

Are you just trying to heat 2500 sqft in a shop to 50 deg?

 

[landrand]

Are you just trying to heat 2500 sqft in a shop to 50 deg?

Yes. Above I posted pics of the 5,000 sq. ft steel building. I'm going to build a couple of inside insulated partitions (metal machining, welding shop/ woodworking shop) that would be probably half of the building (approximately 2500 sqft). I don't anticipate needing the temp to be much above 50 deg F.

The building is not my at my house. Instead, it's about a 1/4 mile away. It would be nice if I would only have to build a fire in the wood boiler a few times a week which would be enough to keep the heated space around 50 deg. If I'm not at home for a week or so, the secondary propane boiler would kick in.

 

[NateB]

In my opinion after installing a boiler and storage to heat my house, garage, and DHW. If I were just space heating a work shop, I would pick a central location, and put in a wood stove. Don't get me wrong it would be a fun project if you have the time and money but it is over kill.

 

[landrand]

In my opinion after installing a boiler and storage to heat my house, garage, and DHW. If I were just space heating a work shop, I would pick a central location, and put in a wood stove. Don't get me wrong it would be a fun project if you have the time and money but it is over kill.

I thought about this, but here's the issue. I live in the UP of Michigan so the winters are severe. I don't know what the average winter temps are, but we have plenty of below zero days and it rarely gets above 25 deg in the winter.

I plan to retire in a couple years and will be using the shop a lot, but I probably not every day. I would like to have areas that I can use for welding/metal working and also another area for wood working, etc. Ideally, this should be two separate areas and a centralized wood stove wouldn't be ideal.

With a wood stove, it would probably take several hours to get the space up to a somewhat comfortable temp. Soon thereafter, the shop temps would then go below freezing when I left for the day or days.

A propane furnace could be used, but since I basically have "free" wood from my sawmill operation, I thought it would be cost effective to use wood to heat the shop areas.

 

[stee6043]

Similar/adjacent idea to Nate's:

I think you're over-complicating your heating needs. Heating a mostly unoccupied and (likely?) under-insulated building with a gassifier setup with storage is going to be frustrating. Gassers with storage are most effective when the run all-out for a period of time to charge storage and then you repeat before your storage drops below a certain temp (mostly 140 for us water to air guys). How will you manage this with your outbuilding? Bringing 2000 gallons of water back up to useable temp is no small feat for a 60KW boiler.

My two cents - save your money on setting up storage and invest in one or two Modine water/air blowers. Start a fire when you go into the workshop and let the water circ to your blowers. Shoot, with the right blower units you could heat the entire building while you're using it. Shut it down when you leave, repeat when you return. You'll likely need to use antifreeze but this isn't the end of the world.

If you go the route of building two "spaces" in your building that you intend to keep warm constantly I'd wager within two heating seasons you'll abandon that process/setup. You're going to be a slave to your tank temps whether or not you're using the building. That's going to get old really, really fast.

Why a slave to the tank temps? 1.) You can't leave the system untouched for "too many" days at a time for fear of freezing and 2.) the colder you let your tanks get between uses the longer your boiler has to spend just heating the tanks and only marginally providing usable output.

 

[BoiledOver]

In support of the OP's theory. Maintaining 50°F for a well insulated 2500 sq ft space would be easily done with the mentioned setup. I would suggest implementing outdoor reset to control a mixing valve. The storage will hold a bit more than 1 million usable btus which could last from 3 to 7 days depending on outdoor temps. Keep in mind the firewood will be sourced on site, meaning minimal additional processing and handling. With a double envelope, there will be minimal heat loss to windy conditions.

Is the setup a simple solution to the described needs? Probably not the simplest. It does however have potential for further expansion if other demands arise. And as @maple1 stated, place the storage within the heated space. I can say that my shop does not fall below 50°F, and that without any emitters. The shedding from storage is minimal but added to the radiation from the recharge firing, the shop is very comfortable throughout the winter.

 

[warno]

I will agree with everyone saying stacking horizontal is fine. I have three 250 gallon stacked horizontal and they stratisfy just fine. I have 3 sensors, top middle and bottom, on each tank.

 

[dogwood]

Landrand, My 170,700 btu/hr Tarm Solo Innova 50 takes maybe three hours to heat a thousand gallons from 140 to 180, so I'd estimate less than twice as long for you to to heat your two tanks with the 198.000 btu/hr your Solo Plus 60 will put out. Those nice tanks, you got for a good price by the way, look like they'd be easy to plumb together side by side. Do you have any drainage taps on the bottom you could utilize for returns? Your building looks plenty big enough to place both tanks inside against one wall, along with the boiler. I'd avoid stacking your tanks since they are about 10.000 lbs. when filled, plus who needs the extra work and plumbing if you have the space. I framed mine in and built shelving space for big items and lumber over them, so no wasted space there

One 1000 gallon tank does me fine in Virginia in a well insulated 3000 square foot home. I have to burn twice a day in the coldest weather. I'd think two tanks would serve you well in your colder climate. Get out your calculator and figure out how many btu's you can store in your two tanks and how many would be needed to heat your insulated partitioned space on the coldest days. There are heat load calculators on line. I did five of them and averaged the results to size storage.

Like BoiledOver said, you'll be surprised how much excess heat your boiler and piping might emit that will help keep your rooms warm Plus some heat will escape storage, but not be wasted if you have it within the partitioned space as Maple pointed out. My biggest mistake with storage was not to get it spray foamed, as it's in an unheated space. Similar to you, I'm going to add a 24 x 40 workshop next year, adjacent to my home and hope to hook up my storage to keep that space at 45-50 degrees when unoccupied, and 70 when I'm in there. I hope to be using a single water to air Modine as an emitter to heat that open space using just my current storage. But I've yet to calculate how big that unit will need to be. Good luck with your project. I'll bet you'll be happy with the results, especially with all the slabs you have on hand already to burn. That's a blessing and eliminates half your upkeep. Don't forget to make sure they're dry to 20% or less.

Mike

 

[Coal Reaper]

dont forget expansion tanks! i think its cost me $1000 for the required acceptance volume to handle 1000 gallons. those tanks pictured look really nice.
i built a 10x30' workshop in my 25x50' pole barn. the boiler and expansion tanks are inside shop. storage is two 500g tanks vertical in the barn part. workshop has 1" spray foam and stays 65-70*.
shame you cant easily do in-floor heat. the cheap guy i am, i would would put them 1000 gallon tanks in the middle of the insulated shop and turn the tops into workbenches or storage shelves. i would foam under the tanks and just plywood box the rest. the attempt would be to try to use the tanks themselves as radiators since you dont seem to be too picky about the temperature in the shop. you can play with the exposure the get the BTU leak through the plywood that you desire. plumb provisions for future heat emitters if needed. though not professional at all (and there is bound to be disagree), this would give you a place to start. if it ends up being too much heat, you can always foam in place at a later date.

 

[landrand]

Similar/adjacent idea to Nate's:

If you go the route of building two "spaces" in your building that you intend to keep warm constantly I'd wager within two heating seasons you'll abandon that process/setup. You're going to be a slave to your tank temps whether or not you're using the building. That's going to get old really, really fast.

Why a slave to the tank temps? 1.) You can't leave the system untouched for "too many" days at a time for fear of freezing and 2.) the colder you let your tanks get between uses the longer your boiler has to spend just heating the tanks and only marginally providing usable output.

When I'm not around to feed the wood boiler, wouldn't my secondary propane boiler be able to maintain the temperature of the storage tanks and surrounding area's to ensure they don't freeze or go below minimum storage tank temps.

I appreciate all the idea's and comments. I'm new to hydronic heating so I welcome all ideas and comments. I'm a computer network engineer by trade so I enjoy sitting around reading, learning, and thinking about this kind of stuff. It's refreshing to learn new stuff.

 

[maple1]

When I'm not around to feed the wood boiler, wouldn't my secondary propane boiler be able to maintain the temperature of the storage tanks and surrounding area's to ensure they don't freeze or go below minimum storage tank temps.

I appreciate all the idea's and comments. I'm new to hydronic heating so I welcome all ideas and comments. I'm a computer network engineer by trade so I enjoy sitting around reading, learning, and thinking about this kind of stuff. It's refreshing to learn new stuff.

Yes, that's right. Backup boiler should keep things from freezing. If that is done much at all, it would be extra important to get your storage into the heated space. Bad enough losing wood heated heat to the outdoors, let alone LP heated heat.

 

[dogwood]

I like Coal Reapers idea of using the tanks themselves as emitters if you can figure a good enough way to regulate their output. I thought about that when I was writing my above post, but couldn't think of a way to do that effectively. Maybe Coal Reaper's provided that solution. It would certainly cut your cost's down. Be on the liberal side when sizing you expansion tanks. I cut it too close trying to save money and had to upsize one of my two Amtrol Extrol expansion tanks to end up with two the same as what Coal Reaper has pictured above. You'll need quite a bit of expansion tank acceptance capacity for 2000 gallons. Pricing on expansion tanks is pretty variable online so look around once you know what you need. There are easy to use expansion calculators on line.

Mike

 

[BoiledOver]

For the expansion tank consideration, 5% is slightly over the maximum that water can expand in volume. Except when freezing (9%) and boiling (woohoo). (broken link removed to https://www.afsupply.com/amtrol-118-153-sx-90v-extrol-vertical-boiler-system-expansion-tanks.html) For more info on those tanks look here. There are larger sizes available too.

 

[maple1]

I have also used my tanks as emitters, when it is really cold out and the basement is not quite as warm as I'd like. I built a simple box/enclosure around my tanks, stuffed with insulation. I can crack one end of the box open to let some heat out if I want. Like a door. It's only foam board.

 

[Bad LP]

Damn, when my 2 300 gallon tanks are up to temp none of us could stand to be near them in the basement. No way would I make a work bench out of them.

 

[landrand]

For the expansion tank consideration, 5% is slightly over the maximum that water can expand in volume. Except when freezing (9%) and boiling (woohoo). (broken link removed to https://www.afsupply.com/amtrol-118-153-sx-90v-extrol-vertical-boiler-system-expansion-tanks.html) For more info on those tanks look here. There are larger sizes available too.

In my hydronic heating education travels, haven't quite gotten to the details of the expansion tank stuff yet....but will be there soon enough. I'm kind of a pack rat and have picked up a couple of water pressure tanks that I have sitting in my barn. They are relatively new and in various sizes. Would a well pressure tank work as an expansion tank or is it for a totally different application?

 

[Coal Reaper]

In my hydronic heating education travels, haven't quite gotten to the details of the expansion tank stuff yet....but will be there soon enough. I'm kind of a pack rat and have picked up a couple of water pressure tanks that I have sitting in my barn. They are relatively new and in various sizes. Would a well pressure tank work as an expansion tank or is it for a totally different application?

i think they cant handle the same heat. maybe if you tied them in to the cold side of storage??

 

[stee6043]

I hope you'll keep us updated on this project!

I still suggest you're not going to get the return on this investment. You'll need some biiiigggggg expansion tanks for 2,000 gallons of storage. And no, typical well tanks are not intended for hydronic/high temp use. You need the proper tanks which are pretty spendy.

These are the proper tanks for 1,000 gallons of storage:

You're also going to need to get a little fancy with your plumbing since you're going to need to be able to send heat to your tanks even when you're not heating the room and be able to extract heat when the boiler is not running. This black-pipe can also get pretty spendy. Controlling two separate circ pumps requires a t-stat and potentially some relays unless you use a line level t-stat.

And along the way in doing all of this plumbing (which is fun) you'll learn (maybe the hard way) things like the fact that the circ pump pictured below is not mounted in the correct orientation. And when pumping 180 degree water in this orientation she'll fail pretty loudly within a few months of operation

You could avoid sooooooo much expense and effort by only heating your building when you're in there....but....we can all appreciate the hobby side of this too. Building a tricked out hydronic storage system is enjoyable...

 

[BoiledOver]

Well since the OP stated in the original post that the purchases have been made for a boiler and tanks, I doubt that scrapping the idea is very welcome. And in my honest opinion, the planned system would be quite simple to manage whether occupied daily or not. With outdoor reset and a target temp of 50°F the 1,000,000+ usable btu's will endure for some time in a dual enveloped structure (minimal wind losses). Pains me a bit to see that Stee has soured to wood boiler systems.

 

[BoiledOver]

i think they cant handle the same heat. maybe if you tied them in to the cold side of storage??

I agree with tapping expansion on a cool line. When storage is fully loaded at anything above 180, the expansion vessels are quite warm to the touch even on the cool tapped line. The tank linked in post #18 would require 3 for the 2,000 gallon storage ($1200). Heck, a used 250 or 300 gallon propane tank would probably get the job done for much less than the 3 bladder tanks. The most expansion (without freezing or boiling) in a 2,100 gallon system would be just under 100 gallons.