New guy DIY heat storage and MB55 Solo plumbing

sardo_67

Member
Sep 19, 2017
202
mid CT
Tarm B55 here and house around 1600sq feet along with a non insulated 24x24 garage with open celling to rafters I would like to heat this winter. located in CT

house is baseboard with some under floor in the living room, most of the walls are not insulated as It was built in 59 and I guess it was an option but has new windows.

garage will be heated directly from the boiler with 2 45kBTU modie heaters and also set up as the emergency head dump zone if my boiler gets too hot. only looking to keep the garage at like 40/50 unless I'm actually working in there

I have seen some of the DIY hot storage tanks from wood and plastic liners which for me seems the best bet as moving large heavy tanks into my basement isn't really possible.

what can you guys recommend for me, 400/500 plenty or 1,000 really needed? I've seen a lot of different set ups.
 

peakbagger

Minister of Fire
Jul 11, 2008
5,348
Northern NH
See my reply in the other thread.

Tank sizing is related to a lot of things. My boilers nameplate is 90,000 btus. A 500 gallon tank holds roughly 4000 pounds of water. I have standard baseboard so i pretty much run out of heat around 140 deg F. I can run my tank up to 190 deg F so the maximum temperature difference in the tank is 50 degrees. Water stores 1 btu per pound per degree F so my tank can in theory store 200,000 useful (to me)Btus. You should have run a heating calculation on your new home so look it up and see how many btus per hour you need on the coldest day. Divide by the storage but capacity and that tells you how long a charge will last you. My boiler can put out 90,000 btus so it takes me a little over 2 hours (2.22) to heat the tank up (its closer to 3 hours). That lines up well with my lifestyle which is start heating the boiler prior to supper and then run it until the tanks up to temp. Once the tank is up to temp my boiler is also heated up with plenty of water with no place to go. I have an external hot water maker so I charge that up with the hot water in the boiler and then run the house heat off of the boiler until I go to bed. I then switch the system over to running on storage when the house calls for heat. I can usually run a day in cold weather and possibly up to three in shoulder seasons but for the last few years I have been heating the house with a minisplit in shoulder season with excess net metered solar.

So if you put in a bigger tank you can go more days between running the boiler but at some point when you need to charge it back up you will need to run it longer. IIf you are just building the house and install radiant emitters in place of baseboard or radiant heat you can heat down to as low as 90 degrees. So the same size 500 gallon tank with radiant can be just as effective as 1000 gallon tank on regular baseboard as there is use for that warm water. Ideally everything is more efficient the lower temperature you can utilize for heating. There are higher output boilers than mine so if you want larger storage you probably want a higher output boiler.
 
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sardo_67

Member
Sep 19, 2017
202
mid CT
I bought the house in June and have not been in it long enough to really see how well heating it is, cost is an issue to me right now as I spent around 30k since getting the house on remodeling and upgrading stuff. I just know that having only a boiler and no storage isn't the best idea unless I am going to be using a lot of heat, the 55 is rated at 140k on wood so it is way over kill for a use like that.

I read more and saw in the other thread I need to make a close pressurized system as I do not want to deal with making heat exchangers and such in an open tank.

however I am looking into that a lot more so it may be a possibility, I still have like 700ft of 1/2' pex left over from my under floor heating installation.
 

hobbyheater

Minister of Fire
Nov 14, 2011
1,134
I bought the house in June and have not been in it long enough to really see how well heating it is, cost is an issue to me right now as I spent around 30k since getting the house on remodeling and upgrading stuff. I just know that having only a boiler and no storage isn't the best idea unless I am going to be using a lot of heat, the 55 is rated at 140k on wood so it is way over kill for a use like that.

I read more and saw in the other thread I need to make a close pressurized system as I do not want to deal with making heat exchangers and such in an open tank.

however I am looking into that a lot more so it may be a possibility, I still have like 700ft of 1/2' pex left over from my under floor heating installation.
This Pdf file is on a home made storage tank. Use pressure treated lumber, stainless steel fasteners, and AST's Liner.
 

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stee6043

Minister of Fire
Aug 22, 2008
2,648
West Michigan
500 gallon propane tanks can be surprisingly easy to move with two guys and a dolly on each end.

Mine were 37" in diameter. Strategically about 2" bigger than my walk-out slider door. Other than the door issue moving them in/out was pretty straight forward...

Just thought I'd share.
 
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sardo_67

Member
Sep 19, 2017
202
mid CT
is there a reason 55gal plastic tanks aren't used? or the other various types of plastic tanks available on CL for somewhat cheap, mostly agriculture use ones?
 

peakbagger

Minister of Fire
Jul 11, 2008
5,348
Northern NH
is there a reason 55gal plastic tanks aren't used? or the other various types of plastic tanks available on CL for somewhat cheap, mostly agriculture use ones?
Plastic tanks are typically limited to 140 to 160 degrees F. Any more than that and the tank will lose integrity. Too low of temp for storage.
 

Fred61

Minister of Fire
Nov 26, 2008
2,442
Southeastern Vt.
Both pressurized and unpressurized have their advantages and disadvantages. One particular thing I like about unpressurized is that unlike pressurized it's simple to get domestic hot water without screwing around with side arms, pumps, etc.
 

Sparky

Member
Feb 24, 2012
64
Southern Vermont
I built a unpressurized storage system like the one in the instructions hobbyheater gave you, Approx. 1200 gallons 8x8 I used copper coils for my heat exchanger (most expensive part) It works quite well. I also used EPDM as a liner. I have a 2400 sq foot house in VT well insulated. In shoulder seasons I can a couple of days between firing. The first tank I built was half the size, That worked ok but the bigger tank is much better. If you need any details or help PM me and I will give you my number and I will help you any way I can
 
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peakbagger

Minister of Fire
Jul 11, 2008
5,348
Northern NH
Although the Kerr design that was linked has some great reference value it sadly advocates an EPDM liner. As many have found out EPDM or various strains of modified EPDM is not and never been rated for elevated hot water storage. Some people have been lucky and perhaps the prior poster was one of them but do yourself a favor and use another material. Sure there are more exotic systems that could work well, the cost and installation hassle is far higher than the cost to get a custom PVC liner built which has been proved in the long term.

There were at least two possibly more manufacturers licensed by University of Maine to make the Richard Hill boiler design. This was the first design wood boiler that required external hot water storage. Sadly many of these installations failed when various home built storage solutions failed. The boilers were costly and storage tank longevity was regarded as an afterthought so many options were tried and many failed. AST had worked with Dick Hill for years to come up with their current design and is probably the best resource on what worked and didnt work.

Ultimately its your call and as long as you go in realizing that an EPDM DIY liner is a science experiment, have at it. Personally I would buy or build a stainless steel tank unpressurized and be done with it if you dont want to go with heat welded PVC.
 

Nofossil

Moderator Emeritus
I'm a huge fan of pressurized storage (I have unpressurized). Major advantages:
  1. Propane tanks are really heavy duty - no failure worries.
  2. No heat exchangers. When charging from your boiler at 185, water in the top of storage is 185. When heating from storage, baseboard water temp is the same as top of storage.
  3. No evaporation loss or condensation in insulation.
Bottom line, gallon for gallon, pressurized storage provides more usable capacity.
 

sardo_67

Member
Sep 19, 2017
202
mid CT
I'm a huge fan of pressurized storage (I have unpressurized). Major advantages:
  1. Propane tanks are really heavy duty - no failure worries.
  2. No heat exchangers. When charging from your boiler at 185, water in the top of storage is 185. When heating from storage, baseboard water temp is the same as top of storage.
  3. No evaporation loss or condensation in insulation.
Bottom line, gallon for gallon, pressurized storage provides more usable capacity.
I am looking for tanks, finding them is a bit hard, I am finding full ones for $200 to $500 now, however I don't need any propane lol
 

salecker

Minister of Fire
Aug 22, 2010
1,082
Northern Canada
Check your propane suppliers,in Canada the specs changed on tanks about 10 years ago. So the propane suppliers had lots of tanks speced for 200 lbs pressure and the new specs were 250 lbs pressure.
Or scrap yards.Or farm suppliers
 

nhtreehouse

Member
Feb 11, 2017
64
New Hampshire
I am looking for tanks, finding them is a bit hard, I am finding full ones for $200 to $500 now, however I don't need any propane lol
I found mine on CL. More accurately, Chris@tarm saw it and emailed me. Thanks Chris! ;) I got very lucky to pick up a 1000 gallon tank for $300. Tanks are out there, you just have to beat the bushes a bit. It's an old ad, but there is a pair for sale in CT:

https://www.hearth.com/talk/threads/2x-500-gallon-propane-tanks.157582/

I've seen stacks of tanks in Mass, around Lowell, and another stack in Portsmouth NH, right on I95. Both of these locations are propane services places.

Good Luck!
 

Bad LP

Minister of Fire
Nov 28, 2014
1,177
Northern Maine
Call any propane company. I know Amerigas in Londonderry NH had a boat load of them.
 

sardo_67

Member
Sep 19, 2017
202
mid CT
I found mine on CL. More accurately, Chris@tarm saw it and emailed me. Thanks Chris! ;) I got very lucky to pick up a 1000 gallon tank for $300. Tanks are out there, you just have to beat the bushes a bit. It's an old ad, but there is a pair for sale in CT:

https://www.hearth.com/talk/threads/2x-500-gallon-propane-tanks.157582/

I've seen stacks of tanks in Mass, around Lowell, and another stack in Portsmouth NH, right on I95. Both of these locations are propane services places.

Good Luck!
THANKS!! I sent him a PM, I tried to post in there but they I can't post in the classifieds yet
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,062
NE Ohio
Probably too low of a temp...but wouldn't it be great if ya could just dump heat to a big ole hot tub, then draw heat off that as needed?! Two birds one stone n all...;) ;lol
 

sardo_67

Member
Sep 19, 2017
202
mid CT
I found a 100 gal propane tank for free since it's out of hydro date and the owner just said take it.
is that even worth setting up or just find the correct 200 gal tank?

I can't fit a 500 into my basement nor do I want to take up that much room, my idea is to get 2 200 gal vertical tanks side by side and a box around them for insulation in a pressurized system.

currently behind on the wood boiler hook up since work went crazy then really low temps so my guy didn't want to cut into my house system that works incase something went really bad and left me without any heating.


also looking for someone who would be able to come and hook up my system for me, my guy may not be able to do it for me.
 

sardo_67

Member
Sep 19, 2017
202
mid CT
ok i will bump my old thread again........

is there any reason NOT to use a new 330 gallon oil tank as a tank for hot water storage? after a lot of searching it will be much cheaper and easier to buy a new oil tank and then use that as my hot water storage tank with insulation around it.


is there any reason not to do this?
 

peakbagger

Minister of Fire
Jul 11, 2008
5,348
Northern NH
ok i will bump my old thread again........

is there any reason NOT to use a new 330 gallon oil tank as a tank for hot water storage? after a lot of searching it will be much cheaper and easier to buy a new oil tank and then use that as my hot water storage tank with insulation around it.


is there any reason not to do this?
Yes there is major reason not to use a 330 gallon oil tank. RUST!!!. A standard oil tank is not designed for pressure, it has to be vented so you are going with a non pressurized system. That means that oxygen is constantly coming in through the vent and causing the tank to rust. It may last a few years but someday you will walk downstairs and find the floor covered with 330 gallons of orange rusty water. Long ago when the first gasifiers based on the UMaine patents were sold (Dumont and Jetstream to name two) they were expensive. Many dealers went with oil tanks for storage as they were cheap, they lasted a few years and started springing leaks. Many of the tanks were stuffed into corners of basements where they were not easy to replace and the boilers got abandoned due to the tanks leaking. Enterprising folks could get the boilers for free just to take them out of the house.

Tom in Maine on this site worked with Dick Hill who invented the boiler design and his American Solar Technics tank was designed to act as a replacement for these old oil tanks used for thermal storage as they failed. Once the old tank is cut up and removed (a major task), the AST tank gets brought into place in pieces and assembled where its going to end up although it does need to be set up away from the wall to get some screws in before being pushed in place.
 
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jebatty

Minister of Fire
Jan 1, 2008
5,747
Northern MN
My first storage system was 3 used oil tanks, leaving an expansion gap and a vent in each tank. Just one of the many mistakes I made in designing and plumbing my Tarm heating system in 2007. Within a year one of the tanks sprang pinhole leaks. End of the oil tanks, and I got a retired 1000 gal LP tank for storage. When I drained the steel tanks, out came some very orange rusty water.
 

maple1

Minister of Fire
Sep 15, 2011
10,484
Nova Scotia
I would scrounge all the junkyards - or metal recycling depots - around within an hour or two drive for used LP tanks. Even 100 gallon ones would work, you could plumb a few together.
 
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salecker

Minister of Fire
Aug 22, 2010
1,082
Northern Canada
A guy i know used 4 new oil tanks as storage.His house was a two story plus basement.He had to get a couple of beams,put the 4 tanks right beside each other as a sandwich.Put a beam on each side in the middle and cabled them together.The head pressure was making them bulge.They lasted about 8 yrs till they started to leak.Now he has no wood fired boiler.
 

sardo_67

Member
Sep 19, 2017
202
mid CT
well god damn, noted.

a member here still has his two 500 gal propane tanks hes selling, i texted him and will be picking them up this weekend.

since my basement isn't massive and i can't even fit the tank in i will cut them down to about 6ft then stand up vertical, make legs and also bolt them to the wall. after they"re plumbed in i'll build the insulation box around them.

so i am guessing i will have 700-800 gallons of water storage for what is basically a 1,000sq foot house with mostly no wall insulation and 24x24 insulated 2 car garage. it's only my GF and i in the house so we don't use the 2nd floor for anything more than storage so heating it is not a concern for me. mostly will be learning my boiler and seeing what happens.


so with the propane tanks i don't have to worry about rust since they are much thicker?
 
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