Low-tech solutions for homeowners that don’t cost the Earth

A smarter, more ecological way to cool our homes in summer

Our previous low-tech article focussed on a natural activated carbon, called biochar, which makes up eco water filtering systems. In this piece we zoom in on swamp coolers, a natural and energy-efficient air conditioning system. It may be a simple air-con device, but it addresses complex climate issues. Let us introduce our third star solution: a swamp cooler.

Star solution 3: Swamp coolers

Also known as evaporative coolers– swamp ‘air-cons’ are a must have item when living in semi-arid or desert environments. As the name has it, they cool the ambient air and increase humidity. Not only do they beat the air-conditioning units in terms of cost, if not efficiency, but they do that without heating up the planet while cooling our living space. Swamp coolers are manifold today. Not to mention the advances in ecological engineering their re-designs boast so that we can live far more sustainably.

How do swamp coolers or wet air coolers cool the air?

The simplicity of swamp coolers startles most people. The air cooling is possible thanks to a very simple gaseous exchange of molecules in the hot air. As the warm air passes through the unit, it interacts with cooler water particles. In turn, the cooler water draws the heat from the hotter air upon entering and it cools it down. This form of cooling by evaporation has been prevalent in many cultures for millennia until the modern day emergence of standard AC units. As a result, tons of refrigerants have been used since then to perform this exact task at a huge cost to our climate and environment.

<img decoding=
A DIY swamp cooler

But how did we cool our homes before the AC innovation?

In North Africa and Andalusia, which have similar hot and dry climates, people resorted to the oldest and effective method of passive cooling. They hung wetted cloth in doorways and windows that allowed the hot air to cool as it passed through the openings while humidifying the living space. This is a highly desirable feature of swamp coolers when used in dry climates. Ordinarily, this extra humidity makes breathing more comfortable. The opposite is true of colder climates; two-stage evaporative coolers are more suitable as they emit less humidity.

Swamp cooler vs. AC unit

The biggest differences between the two types of air coolers are the cost of building and running the units. They also differ in their mobility. Unlike AC units that are fixed to the walls and cannot be moved, the swamp coolers are portable just like heaters.

Another, more staggering contrast is their environmental impact. With just over 1bn single-room air conditioning units in the world today and their numbers rising, the International Energy Agency (IEA) predictions are bleak. Air conditioners rely heavily on electricity, often putting a strain on the grid. This alone will produce an additional 2bn tonnes of CO2 a year if we use air-con units as readily as we are doing right now. Ironically, warmer temperatures and heatwaves lead to more air-conditioning and vice versa. To put it in a nutshell, the technology is causing our demise.

<img decoding=
Air-conditioner factory, Wuhu, China

Also, AC units come with a high cost of waste disposal. On top of that, air conditioning damages our planet’s natural climate defences. How? These conditioners produce chemical waste in the form of Freon. It is a chlorofluorocarbon (CFC) that makes holes in the Earth’s ozone layer.

What is Freon and how it affects our climate

The application of CFCs has been controversial over the years. The manufacture of fridges, freezers and ACs uses these ozone harming gasses, although newer models employ safer refrigerants. This is largely due to improved regulation of phasing out ozone-depleting chemicals in the landmark agreement; The Montreal Protocol signed in 1987.

So, if you use an AC unit made before 2003, it is certain to contain Freon gas. By design, swamp coolers are also a healthier cooling option than AC units. In fact, the AC units run as closed systems; they re-circulate the same air over and over, which is bad news for your health. In short, the device can trap bacteria whilst outputting dryer air into your rooms. Frequent flyers, factory, and office workers are social groups that suffer from sore throats and respiratory problems as a result of long hours in air-conditioned spaces.

<img loading=
A larger commercial swamp cooler

Swamp coolers – a cool story of success

Swamp coolers have been a real hit in the American southwest and Australia. As a matter of fact the demand for this type of cooling has been so high that it has echoed the trend further afield. Today, there are hundreds of variations of swamp coolers, ranging from simple DIY portable coolers to large, and more complex commercial units. And there is a choice of designs for everyone, too. You can either opt for a simple, economical but effective DIY air cooler that is an upcycled cooler box, now upgraded with a fan. Or a more sophisticated, all-singing, all-dancing device with multiple speeds of airflow, like the one featured in this article.

Helping fight the climate crisis with swamp coolers!

With global temperature rises marked with spikes in heatwaves and fuel prices, all types of ecological and economical coolers are likely to become cooling option of choice, also in Europe. The future of our climate hangs in the balance. If we want to escape this air conditioning trap, we as consumers have the power to do this. By buying and using devices that keep us and our homes cool without heating the world. To sum up, eco air coolers and other appropriate tech appliances that sustain the Earth’s cooling capacity are exactly what we need to keep our home and planet’s temperatures low.


Images:  Air-conditioners on the street; DIY swamp cooler; Large swamp cooler; Air-conditioner factory, Wuhu, China.