There is a lot of confusion re solar air conditioners at the moment. This will explain the difference between the two systems and hopefully clarify any misunderstandings around the two technologies.
The solar air conditioner is actually a solar thermal system that uses a solar thermal panel to drive the refrigerant in the system and this makes it about 70% more efficient than the standard air conditioner.
In simple terms, the solar thermal panel is connected to the condenser unit and the air con unit and utilises the sun’s power to drive the refrigerant in the system instead of using electricity as a normal air conditioner does.
In the image on the right, you can see the solar thermal collector on the roof connected to the single condenser unit which is connected to the indoor wall and cassette units.
The efficiency of solar air conditioners also comes from the fact that the SINGLE condenser unit ( the one with the fan) can run up to 4 different wall / cassette units on ONE Thermal panel instead of each unit needing it’s own condenser unit as in typical air conditioner configurations.
This is basic structure for solar air conditioners used in residential installations.
Originally designed for commercial installations only to help reduce power consumption in office buildings, shopping centres and manufacturing plants, solar air conditioners are now available for residential installations as well.
The residential units use the same technology on a smaller scale and the solution offers multiple units running off a single solar thermal panel.
This is one of the MAJOR differences between the solar conditioners and the Solar Powered air conditioners.
Remember that the solar air conditioner still runs off electricity – it is just much more efficient!
Solar powered air conditioner VS Solar Air conditioners.
This is effectively an off grid system, using solar panels and a PV System ( much like you would have for your home) to drive the air conditioners.
This system would require solar panels, batteries and inverters (like a regular off grid PV system) to run the air conditioner.
As tempting as this sounds, the issue here is one of power. Regardless of whether you use an inverter air conditioner, you still need to have enough battery capacity to run a 9000 BTU / 10 000 BTU air con unit and this requires a LOT of battery power.
The reality is that for the price of a good quality properly installed PV system to JUST run an air con unit, you are better off installing a PV System to run the house and then installing SOLAR AIR CONDITIONERS reduce the energy requirements for the air con units.
Solar air conditioners – pricing comparison.
The biggest difference between solar air conditioners and solar powered air conditioners is the price.
Remember that a solar powered (PV) air conditioner needs PV Panels, batteries and inverters to drive the system and enough power to run it even when there is no sun.
Bottom line, if there is rain for 3 days or really cold , cloudy weather – your PV Powered air conditioners won’t run.
To give you an idea , to run a single 9000 BTU air conditioner from a PV powered system would cost around R200 000! Yep…this is because of the components needed to run it and the installation.
Whereas a multi-split system using 4 X 9000 BTU air conditioners running off the solar air conditioner system would cost around half that to install and supply for a whole house!
The figure above is a ball park and it could even be less – maybe around R80 000, but the fact is that the saving of 70% on the energy consumption would deliver a much faster return on investment for Solar Air Conditioners than for a PV powered system.
With technology advancing , it is certain that solar air conditioners are going to become more prevalent over the coming years.