Heat store

[rary]

I have a 20lt. clear plastic container, a couple of weeks ago I suggested to Nicos to place some black containers filled with water in some fruit trees to try and save blossom being damaged by frost, now I would like to know if I filled my container with water and sat it in the greenhouse would it act as as a heat store, I don't want to paint it black

[SarrissUK]

Yes, it absolutely will The bigger container and the more it is in the sun during the day, the more difference will it make at night. I have no science to back it up with though, but I have used the big pop bottled around tender plants in the past to keep frost off them, and that always seemed to work.

[quanglewangle]

(Anyone is welcome, encouraged even, to check my arithmetic and my physics)

Say your 20 l of water heats up by 5°C in the sun
That means it acquires 20*5*4,200 Joules of energy. That's 420,000 J
Let's also say that it cools down by the same 5°C over an 8 hour night, i.e released the energy.

(A Watt is a Joule per second of power.)
8 hours is 28,800 seconds

420,000/28,800 is about 14W

So the effect is equivalent to a 14 Watt heater running for 8 hours overnight.
Not a lot, but not nothing.

[veggiechicken]

That's most impressive, qw!

Can you do the one about running gas, electric and water to 3 detached houses without any of the pipes crossing each other? I've been puzzling over that since I was in junior school.

[rary]

Thanks for the answers folks, Sarriss the answer of " yes it absolutely will" is good enough without the science, and qw, as VC said very impressive, I understood what you were saying, up to "that means it acquirers, then picked it up again at,Not a lot, but not nothing I am not into physics, but I am grateful for the answer and VC even I could put three continues pipes into three houses without crossing pipes

[veggiechicken]

But they're not continuous, rary - although, having goggled for the puzzle there is a solution (but I don't like it. Its not fair play).

As for your tub of water, you've overlooked one thing. You need sunshine to warm the water and you're always saying that you don't have sun where you live.

[quanglewangle]

That's most impressive, qw!

Can you do the one about running gas, electric and water to 3 detached houses without any of the pipes crossing each other? I've been puzzling over that since I was in junior school.

I am not sure teachers are born mean or if teaching makes them that way.

See the Seven Bridges of Konigsberg problem if you cant sleep.

Edit. Suppose you want solution.
Lay all three pipes in parallel, place houses over pipes with services T'ed off up into houses . Supply servises from one end, seal other end. No?

[rary]

^^^^^^ I would have left her guessing

[rary]

As for your tub of water, you've overlooked one thing. You need sunshine to warm the water and you're always saying that you don't have sun where you live.

As I spend a fair bit of time in the greenhouse the water container will pick up the heat from my sunny disposition

[veggiechicken]

^^^^ and the warmth of your smile (before you put your teeth in).