Solar air conditioning, sometimes also referred to as solar cooling, is something people don't think much about but it's a very practical reality that is growing in popularity. Thus our headline!
Books and information about topics such as solar electricity, passive solar heating and solar home heating are everywhere but when it comes to solar air conditioning we are far less knowledgeable.
What we do know is that when the sun is shining brightly and the temperature rises we get to a point where our homes become uncomfortably warm and we want to cool them down.
When that happens what do we do? We switch on the air conditioning system and our electricity meter speeds up as we gobble up a tremendous amount of electricity. Our house certainly gets cooler, but at what cost?
In warm climate countries this is quite an issue. If you multiply the effect of thousands of air conditioners being switched on at much the same time you impose a tremendous load on the local grid. This often leads to power outages.
Worse though, it leads to massive expenditure on network upgrades and that means increases in the price we pay for electricity.
So how is solar cooling any different?
Solar Air Conditioning Explained
The sun shines, everything heats up and it seems counter-intuitive to talk about using that radiant energy to cool our homes.
However, the concept is really quite simple...
You use the solar collector to absorb heat and then you pass the heat through a thermal cooling system which produces cold air which can then be ducted into your home.
There are various methods of producing the cool air stream as various companies research how to come up with the most efficient system.
Let's look more closely at one method...
Solar air conditioning using an existing evaporative cooling system
There are people who already have an evaporative conditioner, sometimes referred to as a swamp cooler. These work by passing cold water over pads and a fan cools the water which is then ducted into the home. Of course these types of cooling devices are powered by electricity, although it must be noted that it uses a lot less electricity than a standard reverse cycle air conditioner.
Exit the electricity...
Yes, instead install a solar panel, convert your existing cooler to DC and “bingo”, you have the power for your cooler, entirely free. Install a back-up battery, if you like, to cater for times of heavy cloud. But you have a simple solution that will save you big dollars on your electricity bill.
See an example in the following video:
Solar air conditioning using a solar collector system
In this case, instead of a solar panel, you have a solar collector of some kind to absorb the sun's heat. Normal flat plate collectors can be used but increasingly now, use is being made of evacuated tube collectors. An anti-freeze solution (glycol) is circulated through the tubes and also through a chiller unit which produces cold air for circulation throughout your home.
Solar companies are actively researching variations and improvements on these systems so we may well see even more efficient systems come to market.
Electricity is used in these systems for running pumps and fans, but the usage is far less than a normal air conditioner working on the local grid. Estimates vary from 50-70% savings on your electricity usage.
To finalize this article please take a few minutes to watch the next video which not only highlights the problems with normal air conditioners and the damage they do to the environment, but also explains how modern solar air conditioning systems are really versatile.