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'[OT] Bilge pumping a slowly sinking ship'
2019\01\06@182512 by Isaac M. Bavaresco

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Em 26/01/2019 18:43, James Cameron escreveu:
> Analogy; I'm on a sinking ship and pumping out bilges as fast as
> possible; there are leaks everywhere, the lower the ship gets in the
> water, the more pumping is needed.
>
> Actual situation; the ship is a house, the water is heat.

It is the exact opposite. In the ship, the water comes from the outside
and makes the boat heavier and heavier. It sinks deeper, what increase
the level difference and makes easier for the water come in.

In the house the heat is produced inside. If the outside is hotter than
the inside heat will flow inwards, but as soon the two temperatures
equalize, the inside will start to become hotter due to the heat
produced by the people's bodies, stove, refrigerator, etc. With the
inside hotter than the outside, heat will flow automatically from inside
to outside.

That is, if unattended, the ship will develop a positive feedback
runaway sinking, while the house will develop a negative feedback self
leveling condition.

Cheers,

Isaac



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2019\01\06@215213 by mike brown

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I'm with evaporating the water on the condenser coils outside.  This is how
cheap window units increase their efficiency, by splashing the condensed
water onto the coils.  Maybe erect a tarp/shield to keep direct sun from
hitting the surface of the roof and walls.  Add a window unit if you can
find one, they perform better than you'd think because they aren't piping
the cooled air through a hot attic.

On Sat, Jan 26, 2019, 20:22 RussellMc <spam_OUTapptechnzTakeThisOuTspamgmail.com wrote:

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2019\01\06@220116 by Denny Esterline

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>
> You might be able to increase the efficiency of your AC system by
> spraying a mist of water on the hot coils outside.  That depends on the
> availability of water where you are.  You would want to do a test by
> measuring the temperature on the freon line returning into your house to
> see whether it was effective.
>
> This _absolutely_ does work. But be mindful of your water source and
what's in it. Easy enough to build up calcium/lime/rust to the point that
the unit is useless.

-Denny
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2019\01\07@175000 by James Cameron

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Thanks for replies.

Alan, yes, and we wonder where the hive is.

Isaac, yes, a negative feedback self leveling condition, but way
hotter than habitable without pumping.

Gordon, thanks for the calculation, very useful.  Yes, in my childhood
my father piped town water at very low rate to the window mounted
air conditioners to increase their efficiency.  One of my jobs was to
maintain the piping system.

Danny, thanks for pointing out water quality.  The hindrance here is
quantity; we don't have enough plumbed rainfall collection area to do
it.  Plenty of unbuilt area to catch rain with, but nothing to keep it
from going straight into the ground or running off.  Rain is also
rare.  Atmospheric extraction is something I'd like to try.

Russell, thanks for the thermal energy storage in water.  Yes, power
is from solar photovoltaic array, a few months old.  In these
temperatures at full sun it is delivering about 80% of specified
power, instead of the usual 110%.  When a cloud covers us for a while,
and the sun shines, power is closer to 100% of specified until the
panels warm up again.

-- James Cameron
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2019\01\26@154326 by James Cameron

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Analogy; I'm on a sinking ship and pumping out bilges as fast as
possible; there are leaks everywhere, the lower the ship gets in the
water, the more pumping is needed.

Actual situation; the ship is a house, the water is heat.  It has been
a bit hot lately.  Yesterday's maximum 48°C 118°F, with overnight
minimum 32°C 90°F.  Maximum has not been below 48°C 104°F for 32 days.

Three split-system reverse-cycle air conditioners (Daikin) are set to
maximum fan and minimum temperature (18°C).  They increase comfortable
living space, with unused rooms closed and sealed.  They are run
continuously; load varies from 3kW in the morning to 7kW in the
evening.

Floor temperature peaks at 33°C 91°F six hours after the peak shade
temperature.

So a thermodynamics challenge; does water added by ultrasonic
humidifier increase cooling?  About 3 litres every 12 hours.

The power draw of the humidifier seems minimal.  I'm predicting the
water would take heat from the floor and air, condense on the air
conditioner, and fall outside via a drain.

(The drains are of great interest to kangaroos, wallabies, birds,
wasps and bees.  One is a favourite of the bees; they are lined up
side by side, taking turns, about twenty of them at a time, and
there's a flight path off into the forest.)

Also, do systems with heat pumps benefit from thermostat cycling?

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2019\01\26@161309 by AB Pearce - UKRI STFC

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> (The drains are of great interest to kangaroos, wallabies, birds, wasps and bees.
> One is a favourite of the bees; they are lined up side by side, taking turns, about
> twenty of them at a time, and there's a flight path off into the forest.)

The bees will he using the water to control the humidity level inside the beehive. Otherwise the honey will do things such as crystallise. That will be why there is a continuous trail of bees between the water and the hive.



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2019\01\26@201144 by Gordon Williams

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We've been hearing about the record setting temperatures down there.

Here in Canada we have been getting days and nights in the -20 to -30
deg C range of late.  Maybe we could do a swap??  Run a big heat pipe
from here to there?

The 3 L in 12 hours doesn't sound very much.  I would be concerned with
raising the RH without dropping the temperature very much and therefore
increasing your discomfort level rather than improving it.  Dry air is a
lot more comfortable than humid air.

Lets take a crack at it to see the effect.

Latent heat of evaporation of water:  2256 KJ/Kg

Mass of Water: 3 Kg

Time: 12Hr * 3600 sec/Hr = 43200 sec

Watts of Cooling = 2256 KJ/Kg * 3 Kg / 43200 sec = 0.157 KJ/s or 157 W

So a couple of old fashioned light bulbs.

You might be able to increase the efficiency of your AC system by
spraying a mist of water on the hot coils outside.  That depends on the
availability of water where you are.  You would want to do a test by
measuring the temperature on the freon line returning into your house to
see whether it was effective.

Good luck.

Gordon Williams



On 2019-01-26 3:43 p.m., James Cameron wrote:
> So a thermodynamics challenge; does water added by ultrasonic
> humidifier increase cooling?  About 3 litres every 12 hours.
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2019\01\26@211602 by RussellMc

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On Sun, 27 Jan 2019 at 09:44, James Cameron <quozlspamKILLspamlaptop.org> wrote:
(The drains are of great interest to kangaroos, wallabies, birds,
wasps and bees.  One is a favourite of the bees; they are lined up
side by side, taking turns, about twenty of them at a time, and
there's a flight path off into the forest.)

Photos please !!!!

I'd look at the possibility of using evaporative cooling in parallel to the
air conditioners.
If you can evaporate liquid water and then vent it outside you should get
net gain.

fwiw Thermal energy storage in water is ~= 850 litre.degrees-C per kWh.

If you are using solar power for the energy source then you can get a
useful % mo by cooling the panels below usual sorts of Tpanel.
A film of water running down the outer face works.

You MAY be able to implement a crude very-large and useful Vuilleumier
machine or a Gifford-McMahon machines, using the house for the air spaces.
VM: move air between hot space and medium space. Pressure swings are used
to Stirling cycle pump a cool space. NO mechanical compression of air -
just air movement.
GMM: Cycle system pressure to nsuck heat into cooler and then drive it out.

    Russell

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