Water/Greek Columns/Math help needed

I've seen in other posts, that a barrel of water in a greenhouse (or more than 1 barrel) would help slow the swing of temperature from day to night.

Would this be useful in incorporating barrels of water into walls, tables, etc. in a home to maintain heating/cooling needs?

As I understand, the ancient columns were rounded stacked stones and once the height was reached- the exterior was coated/decorated to make the uniform design on the column.

Would stacking 3 55 gallon water barrels, coated by 2 or more inches on concrete, would it offer structural support like in a wofati type structure.

I know this would weigh over 700 pounds, but might cost less then 20 dollars a column, especially if non insulator mix of papercrete was used to cover the column.

Further, what would the heat exchange properties be with a house full of these columns.

Could this be safe/useful for passive heating and cooling?

I think a typical newish 55 gal. drum is made to take the weight of having 2 full drums stacked above it, and many fluids are heavier than water which would be roughly 450 lbs per drum. There should be a safety factor involved to allow for probably double that, before the bottom barrel wants to fail. I can only wonder how much support a concrete outer shell would add.
Make sure the structural weight on the top barrel is distributed on the outer rim only, as evenly as possible.
Would also weld inlet & outlet fittings on the barrel sides.

Logan Jonker wrote:I've seen in other posts, that a barrel of water in a greenhouse (or more than 1 barrel) would help slow the swing of temperature from day to night. Would this be useful in incorporating barrels of water into walls, tables, etc. in a home to maintain heating/cooling needs?

For continuously occupied interior spaces, increasing thermal mass helps with both heating and cooling needs. Combine that with access to solar radiation, and you can heat with free energy.

Would stacking 3 55 gallon water barrels, coated by 2 or more inches on concrete, would it offer structural support like in a wofati type structure. I know this would weigh over 700 pounds, but might cost less then 20 dollars a column, especially if non insulator mix of papercrete was used to cover the column.

I would talk to an engineer before using anything innovative as a structural element.

Further, what would the heat exchange properties be with a house full of these columns. Could this be safe/useful for passive heating and cooling?

For thermal mass properties, I would either use just the water filled columns, OR concrete columns. The advantage of water is that convective currents even out the heat transfer throughout the volume, encasing it in slow heating concrete would negate that advantage. Further encasing barrels in concrete would hide any potential problems with water leakage until they became actual problems. Leave water containers where they can be monitored, would be my recommendation.

As to thermal properties, water contains 1 BTU per pound per degree Fahrenheit (8.3 BTUs per gallon per degree F, 62.1 per cubic foot per degree F). Take the range of temperature difference that you are willing to tolerate, multiply that by the BTUs per degree F, to get total BTUs that can be used to moderate temperatures. For example, for 700 pounds of water, and an acceptable range of 61 to 70 degrees, you would have 7000 BTUs to pay with. Given a diurnal cycle, this would work out to around 10 gallons of heating oil per year savings (700 pounds * 1 BTU/lb-°F * 10°F * 200 heating days/year = 1.4 MBTUs/year Heating oil contains roughly 140,000 per gallon.) Careful engineering is required to actually achieve this level of performance!

[note: a 55 gallon drum full of water weighs in at 450 pounds or so.]

Thank You Kindly,
Topher

Topher Belknap wrote:

note: a 55 gallon drum full of water weighs in at 450 pounds or so.]

Doh! I don't know why I was estimating a gallon at a little over 5 lbs- thanks.

I just wanted to add to make sure you have a stable foundation beneath your drums. If you were to stack (3) 55 gallon barrels atop each other they would weigh close to 1300 lbs. That weight would be distributed over the outer radius of the barrel ~ 24 inch diameter (radius 12 inches and assume all the weight on outer rim say 1/4 inch). Quick math to check the pressure on the ground beneath the barrels:
1300 lbs/ 2 * Pi * ( 12 in - 11.75 ) ^ 2 => 3310 lbs/sq in (psi) on the bottom outer ring

That pressure will want to cut into even heavily compacted earth. You would probably want a cement pad around 4 inches thick beneath the column that is perfectly flat. You will also want to make sure the earth beneath the cement pad will not erode in any way.

I believe you can find the structural specifications for any barrel on the web. You need to find the inscription on the barrel they will look something like:

UN 1A1/Y1.2/100/YR

you then search for UN steel barrel codes on the web and see if the barrels are rated for the weight of 2 or more barrels on top of each other.


Simpler solution?
Can you just put the barrels on their sides with little triangle wedges to hold them against rolling. You can then have your plants growing on tables above the horizontally placed barrels.

[edit] typo