In the design stages of my boiler system

You surely are deservedly proud of your log home. As to using empty space at the top of each pressure tank for expansion capacity, and although I think it might work, I also think you will encounter several problems. Pressurized air in the top of each tank will be absorbed into the water, and you will need to have a system for maintaining the air cushion. The air absorbed into the water will add oxygen to your system, and you may have ongoing corrosion issues. There also may be code issues that should be investigated. Others who know more hopefully will chime in with their advice.

I would recommend using the full capacity of the storage tanks and add bladder tank expansion capacity for your system. That will keep your system closed and sealed and eliminate a variety of problems. The cost of bladder expansion tanks will be a relatively small portion of the total cost of your system.

Hi Mark, same as you ,I built a log home and went with an Econoburn boiler to heat it . I am not too far from you near East Aurora, NY in Wales. Since it would take me an hour to type my boiler experience here , why not send me a private message and I will give you my phone number so we can talk. My experience with the guys at Econoburn has been great and I have found their customer service second to none. It is a huge advantage to have them close as we both do. here are a couple of pics of my setup. Gotta go load the boiler , Bruce

mark cline said:

I will meet with Marc Odell at Econoburn on Tuesday to discuss my options. I'm about 2 years out on installing the boiler system , so I have plenty of time to research and acquire the parts and pieces I need. The well and septic will be going in this summer , so I couldn't fill the system until then. I have a 100 gal propane tank that I thought I could use as an expansion tank , no bladder but still in the research stage. I now live in Orchard park and the Log home is in the town of Cattaraugus , NY. I have 175 acres of hardwood but don't want to cut 40 cord of wood per year to heat the house, so any way I can reduce heat loss , the better. I had thought the storage tanks would be put into the utility side of my basement but after seeing your pics. It would be an advantage to only pump 100-120 degree water vs 170F, the 100 ft to the log home . This way I would free up the space where my walk in cooler was supposed to be. I brew my own beer and will need the space later when I retire and convert to a 30 gal brew system .
Back on subject , what did you use to pipe the hot water to you log home? I like the foam in place with 1 1/2" pex . Thanks for the reply . Time to brew 10 gals of my favorite Irish Red Ale.

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Mark, I used logstor pipe for my 60' run to the house , you live are closer to me than I thought if you live in Orchard Park. If you ever want to see my setup you are welcome to stop by, especially if you happen to have some of that Irish Red with you! Tell Mark and Dale hello for me , great guys to deal with as you will see. Bruce Lina

I sent you a private message.

gg

beautiful boiler room / building!

Couldn't open the image of your home, but, sounds beautiful and probably valuable. As a reasonably successful, somewhat retired, and healthy old guy I recommend you consider how you arrange your boiler and storage in the available space to accept future options. My schedule requires me to be away from the house for extended periods of time. After 6 seasons of only wood (and 4 of those without storage), in Fall 2015 I added a pellet boiler to our wood boiler/storage system. Now I have the pleasure of burning wood when it is pleasurable. I love burning wood, but as I get older I'm adjusting to new realities and it's not just our heating needs. Best wishes

Oh... I didn't plan it, but was fortunate to have adequate space on the right side of my storage tanks to add the pellet boiler. Wood on left, pellet on right, and storage in the middle. I wish I could take credit for the genius foresight of our final system.

You might find some tidbits here:

https://www.hearth.com/talk/threads/simple-questions-on-tanks.153012/#post-2054195

If you want to look some more, key words to search would be 'reverse-return' and 'two pipe'.

No idea, don't think I know of those.

Well, sometimes to really optimize things, systems will pull lower demand water out lower than top, and return warmer return water up higher than bottom - multiple ins & outs. But don't think that is an overly prevalent approach - I've mostly seen the simple way. So if you are high & low you should be good. One tapping high & one low on each tank should do, but if your tanks have more than that you could use them if it would help somehow.

Is the middle supply and return in addition to a top and bottom one? Could it be for a fossil fuel boiler to only heat a smaller portion on the tank to prevent short cycling?

Hello Mr. Cline,

Please invest in two books written by Dan Holohan the first being Classic hydronics and the second
being Pumping Away available from Amazon, Barnes and Noble and www.dansbooks.com where you are
purchasing them directly from the author.

I would like to suggest that you consider using a steel expansion tank rather than a bladder expansion tank
as you can run your system at very very low pressures and maintain lower operating temperatures with high
limits of 160 and 140 as a low limit.

The other benefit is that your operating system can operate at 4 P.S.I.G. to 8 PS.I.G. with no issues
and plenty and I mean plenty for heat for your home with low fuel consumption.
You can use a 30+ gallon steel expansion tank with an airtrol valve and fill it once, bleed out the
excess water and have heat that will make your home warm and keep it warm.

Once you have the steel expansion tank bled of excess water and have the proper air charge volume in it
being 1/3 air and 2/3's water.

In my case my steel expansion tank is using 5 gallons of air and 10 gallons of water you never have to fill it
again and you can shut off the autofill valve forever.

The steel expansion tank eliminates the need for oversize plumbing to maintain the point of no pressure change
as required by the air scoop its automatic bleeder and hanging a bladder tank under it or piping to a bladder
tank sitting on the floor.

The beauty of using a larger steel expansion tank is that your system stays at a very very low operating pressure
at all times and still provides you with the needed BTU per foot of baseboard or steel or cast iron radiator or in
floor heating with pex.

Purchasing clean, pressure tested surplus steel or cast iron radiators will provide plenty of steady even heat heat
for you and avoid having them cut up for scrap which would be a waste.

Once you have the boiler drains at the end of the heating runs to power purge the air out of the cold water feeding
them you never have to bleed base board radiators or just bleed the cast iron or steel radiators once and be done with it.

Marc, I have a thousand gallons of pressurized storage and found I needed two large Amtrol Extrol SX-160 expansion tanks (tank volume 86 gallons, acceptance volume 46 gallons) to keep my system operating pressure under 20 psi. I'm guessing if you're going to have three 486 gallon storage tanks you'll need at least as much expansion capacity. Have you used one of those on-line expansion calculators yet to determine how much expansion capacity you need? http://www.amtrol.com/support/extrol_com_sizing.html Make sure to buy expansion tanks suitable for higher temperature hydronics use. Best buy I could find at the time was from AF Supply on Long Island, NY. https://www.afsupply.com/brands/amtrol.html

Tarm Biomass has a multitude of piping diagrams on their site to include piping multiple tanks. http://www.woodboilers.com/images/stories/documents/woodboilerplumbingschematic1211.pdf Good luck.

Mike

The 4 to 8 psi mentioned above won't work very well unless your system doesn't have much height to it.

If I have this correct you have 5,000 square feet of living space?

So the EDR equivalent direct radiation needs to be found;

5000 X .02 = gives you 100 gallons of steel expansion tank.

The steel expansion tank will have 66 gallons of water
in it and 33 gallons of air cushion and it will need the
model ATFL 1" tapping airtol valve with the separate
air vent valve.

If you go to a larger steel expansion tank or a battery of
small expansion tanks to hang in the rafters on a shelf
that is hung from the rafters all the better as it
gives you more of a cushion and you can maintain low
operating temperatures and pressures as the basement
is going to be living space too.

You can use an air scoop with a one inch tapping large tapping
to feed the single steel expansion tanks ATFL airtrol valve and the
separate air vent valve to maintain the proper air water ratio.
all you need is to install a valve in the piping to prevent the loss of the
water and air charge if you need to change a circulator if you do not have
plumbed with isolation valves.

My heating system has been running very well and kept the low pressures
and I am not lacking for heat and I have a very drafty poorly insulated house.

The sq footage wouldn't really have any thing to do with your required expansion. It will depend on how much water is in your system and to what temperature you heat that water.


Sent from my iPhone using Tapatalk

Square footage of your house has no bearing on how much expansion you will need. It needs to be based on system volume & temperature ranges.

mark cline said:

Thanks Leon, I 'll need to do a little research as I'm not familiar with an air scoop or airtrol valve. I know a closed pressurized system is more efficient than an open system , but is a low pressure system even more efficient? Would a bladder system of expansion tank ,sufficiently sized, be able work at low pressure and be efficient? Learning more every day. Thanks

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With my system I barely use 2 bags of coal per day to heat my leaky house using a low pressure system and my house leaks heat like a sieve.

with my steel expansion tank I can have and do have a low operating pressure due to the size of the expansion tank and its 10 gallons of water and 5 gallons of air with low pressure and lower temperature(160 high 140 low).
As I said a 100 gallon expansion tank or for that matter two of them will provide you with plenty of expansion and back pressure to let your circulator run at low pressure. I have one circulator for 2 loops totaling 225 feet and the house is much warmer than when I am using oil heat.

I had a hand fed wood and coal boiler before this and it was just as warm with one circulator.

A closed system is one with either a bladder tank for expansion or a steel expansion tank. A heating system efficiency depends on your heating plant, the heating load, how well the home is constructed and its level of insulation for the home so lets get that out of the way.

You have to decide on whether you want an open system or a closed system. they both work. I hated my sytem when it had an expansion tank as it was not well thought out by the plumber. In their ultimate wisdom/insanity they ripped out a perfectly good open to air expansion tank that hung in the rafters for 30 plus years that had a water level gauge in it and had the hare brained idea that a closed system with a bladder tank was better in 1981-it was not, the system leaked out when my well failed and they had to come out here several times to fill it with water using a jet pump and it was not fun as I had heat and no running water for 7 months because of a lousy well driller.

Its very easy to fill an open or closed system with a steel expansion tank and maintain water levels in the same expansion tank as it has either a sight glass or a gauge glass to check on water levels if you have to change a circulator or have a leak.

With a steel expansion tank in a closed system you fill and let the excess air out of it once and only have to add water back if you have a leak or need to change a pump if its mounted in the wrong place or has no isolation valves. In an open system/ gravity hot water system you have someone watch the water level in the tank in the attic after they bleed the air from the radiators and then its done once the system is filled and the water fill valve is shut.

I grew up with a steam system that had a gas boiler the size of a typewriter table and huge radiators so......................

There are a lot of gravity hot water and steam heating systems that barely grunt in subzero weather to provide heat that lets you live in shirtsleeve comfort.

In floor heating is a waste of money if you have a basement and or an attic that can take full advantage of steam heat or gravity hot water heat in my opinion.

My fathers new home has it and its more trouble than it was worth. the weasels that built the place installed the heating tubing wrong and the tubing did not have reflectors nailed to the underside of the floor boards and the house was freezing until my brother nailed reflective insulation board up to the floor joists.

My fathers wooden floor is also separating in spots and that is not good either.

It does not help that the temperature is 180 all the time and the pressure is to high in my opinion.


People fail to understand that If you have radiators its better to leave them and insulate them on the back side to prevent heat loss and increase the available heat to the room if you do not want to move them to the interior walls where they should be anyway., back then that was not thought of as all we had was rock wool insulation or none at all with good lath and plaster walls.


Please purchase copies of Classic Hydronics and Pumping Away and Dan Holohan explains all this in simple easy to understand terms for the plumber and layperson alike. You will learn a lot about heating when you have read those books. Dealing with fool plumbers is another issue.


You have lots of water mass, take advantage of it by using gravity and simple methods pressure regulating methods that always worked and still work.


A house circulator works just like an irrigation pump, it uses flow at low pressure top move lots of water.

In my system I have the single circulator set at speed 2(17 GPM) and I have no air bubbles and no bleeding to do at all. The pressure from the air charge in the steel expansion tank provides the very low back pressure needed to the 54 gallons of water in the system and as a result low operating pressures and lots of heat at all times.