Off Grid Home Forums Technical Discussion Absorptive A/C viable?

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    Hey all, new member and 1st time poster :)

    I’ve come across the concept of absorptive/absorption refrigeration systems from time to time over the years. I know they have been used in RV and camping application for years a there used to be a few companies that made residential and commercial versions, but I guess they came to be pretty notoriously unreliable. I’ve also been hearing of these making a comeback recently, and I’ve been wondering how viable it would be to build and/or power one by solar means by way of a concentrator? Ideally I would think you would want a ground loop as a primary stage with the absorptive unit functioning primarily as a backup. Anyone experimented with this?


    I just finished reading that Wal-Mart of al people has announced significant energy conservation gains by using among other tehcnologies Absorptive air conditioning. This is all part of their new super center grocery /combination stores design. Find out who builds stores and supplies equipment to them and you will learn more.


    I understand the concept and design of absorptive systems, it’s the matter of using solar as the energy input that I’m questioning such as how much thermal energy can be harnessed from what size solar collector compared to the input needed for say a 5 ton system.

    Commonly available commercial/industrial units pretty much start at 100 ton+ so they are good for scale reference, but that’s about it. I was hoping maybe someone on here had experimented with this and could point me in the right direction on where to start


    1 ton = 12,000 btu, your RV propane fridge and air

    conditioners are absorbtion. 5 tons? how big the place

    and where?



    From the day we’re born, all of us are inspired by our natural instinct to grow

    our physical abilities and knowledge, our family relationships, our talents,

    our friends, and our growing skills to work and earn a good living so we can

    grow our bank accounts and enjoy “the good life”, and then advance our good

    reputation as successful men and women in a prosperous economy for a nation

    of growing influence around the World —- which becomes a problem if other

    people in other nations push forward with their own agenda = World Wars One

    and Two, and the recently ended “Cold War” with the former Soviet Union.

    But even if all the people of the World learn to live together peacefully for

    growing trade and expanding global cooperation, it can’t go on forever.

    Why? Because the Earth, the planet we live on, is not growing. In fact,

    with each volcano and earthquake, it is slowly cooling and shrinking, as it has

    from its beginning with the Sun as an enormous cloud of hot, swirling gases

    slowly cooling and forming the planets Neptune, Uranus, Saturn, Jupiter, Mars

    Earth, Venus and Mercury.

    Yet, it’s hard to find scientists, economists or anyone to admit that, because

    almost everyone assumes we must go right on growing our families and expanding

    our careers and business investments forever; and millions see their own children

    as a financial investment to make the family rich, so the more the better!

    Why not?! It’s certainly good for business to promote a growing population of

    ambitious consumers who always buy more products every year. A favorite slogan

    is “A growing economy is a healthy economy.” If only we could somehow make

    our planet grow right along with us, there would always be more of everything

    for everyone, right?

    So the astronomers and astro-physicists are busy searching the night sky for other

    life-supporting planets orbiting other stars like our Sun, if only we could travel

    millions of miles into outer space. Problem solved! We’ll send high tech robots that

    don’t need food, water, air or sunlight, produce no sewage or garbage and require

    only a little oil, recharge and a replacement part once in awhile. Later we’ll invent

    a safe method of suspended animation, like Sigourney Weaver had in those three

    sci-fi “Alien” films, so living astronauts can sleep through the exciting adventure

    of space travel (!)

    But there is another problem.

    While scientists and businessmen are busy planning to conquer the universe,

    our human population keeps on growing, now 7 billion and counting. So, we face

    a very difficult question: How many people can the Earth support? We must find

    an answer now because, not only is it slowly shrinking, as a living system, it is

    struggling to neutralize the ever-growing mass of our trash, junk and sewage with

    more violent storms and floods, huge tornados, droughts and raging wildfires, all

    happening now around the World because every day growing tons of garbage and

    sludge are dumped in the ocean, lakes and rivers, while big cities like Los Angeles

    are surrounding themselves with growing mountains of “landfill”, while growing

    thousands of coal-fired power plants and growing thousands of jet planes are

    spewing out growing tons of toxic smoke and exhaust fumes, and occasionally an

    oil well is operated below safety standards and suddenly spills tons of crude oil

    onto land and into the sea. But how much can the Earth absorb?

    Each one of us is born with an “auto-immune system”, so if germs make you sick

    with the “common cold”, without you having to think about it, your body will

    automatically raise your temperature, make you sneeze and cough up phlegm, blow

    out nasal fluid, need more water and fruit juice and more sleep, during which time

    the white cells in your blood stream will surround and kill the virus invaders.

    But if you’ve been drinking coffee, alcoholic beverages, smoking cigarettes and

    staying up late, you immune system could be so weak your cold may turn into a

    fatal case of pneumonia.

    Likewise with planet Earth. It has its own auto-immune system that constantly

    absorbs and recycles everything in rainstorms and flooding rivers, hurricanes and

    tornados, hot summer and cold winter seasons. Everything is always moving and

    changing, because the Earth is a “biosphere”, not cold and dead like Mars, or

    broiling hot like Venus, but a living, breathing weather system of four seasons

    we all depend on to grow and store our food and water and to breathe fresh air

    from the photosynthesis of natural forests and the phytoplankton in the ocean

    that together convert the carbon dioxide we exhale into the oxygen we must inhale

    to stay alive. If that systen collapses from the growing mass of our pollution,

    every living thing on Earth will die.

    Therefore, our lifetime job should be to protect that biosphere so our children

    will have a safe and healthy place to live and grow. We should give that to them

    as their birthright with food, clothing, shelter, love, friendship and education,

    which can only exist on a life-supporting planet. To do this successfully, two

    things must be accomplished as soon as possible:

    1. Safely recycle 100% of all garbage and waste materials, or close down their

    source. For example, there is no such thing as “clean coal technology” because

    even if all the smoke from coal-fired power plants could somehow be “scrubbed”,

    there would soon be a gigantic tonnage of carbon waste and no safe place for it.

    Some say bury it, but it would eventually mix with ever-seeping ground water and

    leach into streams and lakes. But the coal seams in their original underground

    locations were harming no one, because over eons of time by slow geologic

    permutations, the Earth isolates its many toxic elements, including coal, oil and

    uranium, so life can evolve. The only reason we need coal, oil and uranium

    is to supply our massively growing population.

    2. Peacefully establish family planning clinics in every neighborhood in every

    village, town and city where each woman is given the legally protected right to

    freely decide if and when to birth her children. Very few women want 6, 7, 8 kids.

    More want none at all, but the vast majority want no more than 1, 2 or 3. Abortion

    is rarely necessary because thousands of childless couples are waiting to adopt.

    In this way, the human race can live in a natural balance with a healthy biosphere

    that provides everything we need because, with less people, work is more valuable

    with plenty of resources for everyone, and thus no possibility of obsessively

    growing super corporations or massive federal bureacracies, no overcrowded cities

    infested with crime and crooked politics, no thousands of air-polluting coal-fired

    power plants, no thousands of oil wells spilling from unsafe rigs and platforms.

    Modern technology has already developed cleaner sources of electricity, like solar,

    wind, geo-thermal, tidal and battery-powered vehicles, which are perfect for a

    smaller and more sensitive human population working as a friendly network of

    locally sovereign towns and villages who trade freely for everyone’s mutual benefit.

    We have the scientific ability to create a virtual paradise on Earth for everyone

    and everyone’s children for a million years and beyond, or we can let our predatory

    instincts grow and drive us blindly and stupidly into ecocide and self-extinction.

    So, how many people can learn about this dilemma now, today, tomorrow, next

    week, next month and throughout this year and next? Is there still enough time

    to change, and will enough people think about it and make a rational choice?

    If you pass this letter on to some one you know, that might help.

    Clinging to a thread of hope,

    John Talbot Ross

    April/May/June, 2011


    “If Saving the Earth” via


    Hello John

    While I don’t disagree with your post I was left with the thought of “why didn’t people see this a long time ago?” I was born in a vey different culture and society. The thoughts you expressed in the first part seem to come from a culture and society I am still getting adjusted to. Ironically there has been a system in place for two thousand years which most people have ignored because it does not suit their own sense of greed which is the prime reason for many of the ills we now suffer from as a society. Other systems have been in existence for even longer and they too have fallen by the wayside because a minority of people found they could flex their power and feed their greed for material wealth and power over others. This is a human condition for which there may not be a cure. There will always be some individuals who figure society’s rules do not apply to them and if they break those rules, one tiny bit isn’t going to hurt. You will find this behavior in a small community of 100 people as well as a city of 1 million. Down through the ages we have had countless examples of communal groups who have attempted to band together in following a set of rules that places the common good above the individual gain. In most cases these groups have been put down as being slightly odd or even stupid; but few people attempt to emulate them. Among the more ssucessful groups are the monestaries and nunneries not to mention theological based groups like the Amish and Old Order Mennonites. The reform mennonites have managed to blend in with society to the extent they are not as visible as a group but you can still hear derogatory jokes told, that essentially denigrades them for the values they hold. Many people will dismiss them as religious kooks becaause they place a higher authority in charge yet this is the only way we are going to survive. It may not be a god but until people are willing to put a value system in place that is above them and superceded their own personal ambitions, we will not achieve the utopia you dream of. I am old enough to remember the flower power children and hippie movement. I remember reading Walden II and Erewhon and BF Skinner’s books and articles. Few people nowadays have even heard of these. The goals and intent are the same but the methods and sometimes the vernacular has changed but it is basically the same wish for a better world that motivates us. Sadly we do not look back to learn from past mistakes, choosing instead to learn by making our own and thus repeating history and making the same mistakes over and over again. I no longer pretend to have an answer. I strive to better myself and hopefully leave some shred of intent to improve the world instead of my bank book. I despair of mankind ever learning the lesson whenever I see my friends and neighbors brag about their material possessions or when they denounce me for not wanting to live closer to civilization and mass nuttiness in the big cities. I moved away from drive-by shootings, gang-land warfare and police road checks simply because I happen to live in the wrong area. I no longer have to lock my door with double locks and dead bolts. When I see someone with a gun I know they are out looking for food not someone else.

    I do not characterize myself as being religious but I have found a societal template in christianity that I think will achieve the goals you profess to want. Trouble is, most beople decline to accept any sort of belief system that compels them to put society’s betterment ahead of their own desires and self gratification.

    When I began buildinbg wind generator controls back in the seventies it was to allow people to live in places away from cities. Lately ‘going off-grid’ seeems to have acquired an aura of being a subculture. It is more of a political movement than anything else. I almost want to say “stop the train I wanna get off!”

    But the train derailed long ago. We are simply sliding along on sheer momentum.


    Dustoffer, I made a point of looking up your link “if saving the earth”

    Without exception every one of the points he raises has been dealt with by an in-depth article by National Geographic Magazine. Despite the huge circulation of that illustrious publication we have failed to make much of a dent in the problems. National Geographic magazine supports research, and documentaries not to mention video and other presentation media in an ongoing effort to make a differeence. No doubt much progress is attributable to the efforts of this wonderful organization. The dearth of progress in any of these areas is simply a measure of the herculean task ahead of us. Somewher I read that every copy of NG magazine is also read by others who pass along the copies. The magazine is translated into dozens of languages and is literally distributed around the world. I cannot think of a better effort at raising the awareness of people around the world to the plight facing our planet. Ther are signs that some people are paying attention. Public awareness is better and programs are now in place that did not exist some 50 years ago when I first startedreading NG magazine in Europe.

    All we can do is lead by example.

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