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RFClark
Super Nomad
Posts: 2431
Registered: 8-27-2015
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Mood: Looking forward to 2024
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JD,
Upon thinking about it solar powered AC can’t add heat to the environment the way that AC run off other sources can. In fact I feel a case can be
made that because 80% or more of the sun’s energy is reflected or reradiated off the solar panels they actually may reduce the amount of heat stored
in the ground beneath them.
The AC unit uses the collected solar energy to move heat around rather than generating new heat. The combination isn’t making things hotter in the
way that AC powered by thermal generating stations can.
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ORphil
Junior Nomad
Posts: 87
Registered: 11-24-2019
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No, no Tio. Don't dodge the main question I had. What about the CCC and the WPA building infrastructure for the common good of the people that we
still enjoy today? Communism? Left to the utilities, we wouldn't have fiber optic in many rural areas that we do now due to fed dollars. Not much
different from bringing electricity to the nation during the new deal.
If it makes sense to fund and alternative energy sources and programs to make the US more independent and enviromentally friendly no matter what your
"beliefs" are wouldn't that be a positive endeavour? Who is the loser? Oil.
I'm a c'monist. C'mon man.
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Tioloco
Super Nomad
Posts: 2034
Registered: 7-30-2014
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Quote: Originally posted by ORphil  | No, no Tio. Don't dodge the main question I had. What about the CCC and the WPA building infrastructure for the common good of the people that we
still enjoy today? Communism? Left to the utilities, we wouldn't have fiber optic in many rural areas that we do now due to fed dollars. Not much
different from bringing electricity to the nation during the new deal.
If it makes sense to fund and alternative energy sources and programs to make the US more independent and enviromentally friendly no matter what your
"beliefs" are wouldn't that be a positive endeavour? Who is the loser? Oil.
I'm a c'monist. C'mon man. |
Not dodging anything comrade. Your favorite energy "alternatives" dont work and arent needed. We currently have over 100 years of fossil fuels alone.
This is about income redistribution and political control. In time, there will certainly be advancements in energy production that actually work. This
just aint it.
[Edited on 7-15-2024 by Tioloco]
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JDCanuck
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Registered: 2-22-2020
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| Quote: Originally posted by RFClark | JD,
Upon thinking about it solar powered AC can’t add heat to the environment the way that AC run off other sources can. In fact I feel a case can be
made that because 80% or more of the sun’s energy is reflected or reradiated off the solar panels they actually may reduce the amount of heat stored
in the ground beneath them.
The AC unit uses the collected solar energy to move heat around rather than generating new heat. The combination isn’t making things hotter in the
way that AC powered by thermal generating stations can. |
RFClark: Solar may be the least heat producing energy source for AC units, but I was talking about the heat lost in the refrigeration cycle plus the
fact we pump the heat from inside where it would otherwise be absorbed by floors and walls to the outside where it is added to the atmospheric
temperatures.
I have never understood why people prefer multiple fans that create no actual cooling but add the heat from the work done by the motor to the inside
temps. An exhausting fan or fans located on the roof would make much more sense, at least then you would not be adding more heat to the interior.
Better yet, natural exhaust by low level windows or breezeways to draw in coolest air and high level exhausting windows or courtyards to discharge
like I saw commonly in older pre AC building designs in Mexico.
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JDCanuck
Super Nomad
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Registered: 2-22-2020
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I stayed at one hotel in Puerto Escondido that people loved to come and sit at the restaurant as it was naturally cooled by an entrance breezeway
facing the ocean. A large pool was located in the middle of the courtyard and the breeze that flowed over it provided evaporative cooling that
eventually flowed through the dining area at the far end and then up past all the rooms.
I think this was what was behind the reflection pools commonly built at entrances in Middle Eastern home designs and central courtyards. But if I
remember your new home design correctly, you have built something similar into your layout, minus the water pool to provide the evaporative cooling.
I'm assuming you have a high level window in your upper hallway at the far end away from the access stairs?
I also wanted to (but of course never did) put in water sourced AC units. No one I spoke to in La Paz had any idea what I was talking about and the
one supplier we found in Northern US was not helpful in shipping it. Essentially, hot water pre-heaters that you pumped the heat from the rooms into
for AC.
[Edited on 7-17-2024 by JDCanuck]
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mtgoat666
Select Nomad
Posts: 17860
Registered: 9-16-2006
Location: San Diego
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Mood: Hot n spicy
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Planet Sets Record for Hottest Day Twice in a Row
Researchers with the European Union’s Copernicus Climate Change Service said Sunday was Earth’s hottest day. Then it happened again on
Monday.
https://www.nytimes.com/2024/07/24/climate/hottest-day-earth...
Monday 22 July 2024 was the hottest day ever recorded on Earth, with a global average of about 62.87 degrees
Fahrenheit, or 17.15 degrees Celsius, preliminary data showed — beating a record that had been set just one day before.
[Edited on 7-24-2024 by mtgoat666]
Woke!
“...ask not what your country can do for you – ask what you can do for your country.” “My fellow citizens of the world: ask not what America
will do for you, but what together we can do for the freedom of man.”
Prefered gender pronoun: the royal we
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RFClark
Super Nomad
Posts: 2431
Registered: 8-27-2015
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Mood: Looking forward to 2024
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Solar AC cools the environment and your home!
Goat,
Got Solar AC that works during the frequent power outages and actually cools the enviroment?
Mechanical AC has received a large amount of bad press of late. The “truth” is somewhat more complicated. The AC isn’t the problem. The energy
source for the AC is the problem. Thermal generating stations are around 30% - 40% efficient. The balance of the energy is released into the
environment. As dealt with below Solar powered AC actually reduces the amount of local heating rather than increasing it.
First a discussion on building heat loads that mechanical AC must overcome and how to minimize them.
Calculating the heat load in a building can be complicated as there are a number of heat sources.
1) direct solar heating - the sun shines on things and they get hot
2) Conductive heating from the air. Buildings require air exchanges about 6 times per hour. Hot air comes in, cold air goes out. There are expensive
devices to transfer cold from the outgoing air to the incoming hot air.
3) radiant cooling or heating from the ground under the building. Concrete slab construction can adsorb heat and reradiate it when the air is cooler.
Usually the ground heats up as hot weather occurs. Areas adjacent to bodies of water tend to have ground temperatures close to the temperature of the
water. In areas where the ground water is cool or cold this can be a large plus in cooling. Concrete slabs can also store cold from daytime AC
operation and release it at night reducing night time AC requirements.
4) occupants and activities like cooking generate an internal heat load as does the sun shining in through exterior windows.
The first line of defense in cooling a building is to prevent the building from heating up in the first place. This is accomplished by reflecting as
much of the heat as possible from the exterior. Shadow the walls and windows with eves. Use heat reflective paint and/or material backed up by
insulation to reduce heating by radiation through the roof and walls. Reflecting first then insulating reduces the amount of AC required to cool the
interior space.
A second and often overlooked AC load is water vapor. Humidity reduction is energy intensive. Humidity introduced by air exchange is a major part of a
home’s AC budget. Unlike direct solar heating humidity reduction is a 24hr a day problem. Well sealed doors and windows make a huge difference in
the amount of energy required to provide a comfortable environment.
Unsealed cement surfaces adsorb and retain moisture increasing the time required to cool down interior space. Sealed insulated walls allow rooms to
cool faster and allow comfort at higher temperatures by reducing both humidity and interior radiative loading.
Mini Splits are very efficient partly because most of the heat producing parts are outside and most of the cold parts are inside. Unlike systems
employing ducting outside or in interior hot spaces which loose substantial amounts of potential cooling to the environment, mini splits deliver most
of their cooling to the interior of the home.
There has been much discussion of the contribution of AC units to the “heat Island” effect. Solar powered AC actually reduces the amount of heat
reaching buildings and the ground providing a net reduction by direct solar heating making solar AC a part of the solution. Additionally AC generates
significant amounts of relatively pure water in areas with high humidity. The 3.5T of AC we run generates about 20L/hr with a 90% exterior humidity
reading.
“This study showed there were clear differences between the temperature directly below the panels, the gaps between panels, and the control group.
Between spring and autumn, the ground underneath solar panels was cooler by up to 5.2 °C on a daily average compared to both the control group and
the gap between panels. In addition to the temperature recorded in the ground, the air temperature was also found to be significantly cooler by up to
6 °C, however, it should be noted that the air turned slightly warmer under the solar panels during the night.“ https://www.harvestsunsolar.com/do-solar-panel-installations...
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