Solar Cool Solar Air Conditioning is the combination of a high-efficiency 2-stage air conditioning system integrated with our patented solar thermal panel, creating the most energy-efficient A/C system available today!
Unlike traditional photovoltaic panels which generate electricity, our Solar Cool panel generates heat which in turn reduces your electricity usage.
This is done through the process of our Solar Cool panel superheating the A/C system's refrigerant, which then reduces the workload of the compressor!
This results in lower power consumption which in turn saves you energy and money!
Basic Compression Cooling Principle
Most air conditioners and refrigerators use the compression cooling circle. The basic thermodynamic principle lies in the evaporation of liquids: When a liquid evaporates, it extracts heat from its environment.
The cooling circle has to provide a high pressurized liquid which can evaporate. We start with the compressor which compresses a gas to high pressure. For the compressor it is much easier to compress a gas instead of a liquid. The subsequent condenser cools down the hot gas to ambient temperatures. The condenser consists of multiple copper pipings and a fan blowing air around the copper pipes and attached fins. The gas gets cool and changes it state from gaseous to liquid state. The expansion valve consists of a very small hole which opens for a short time and supplies small amounts of liquid into the evaporator. The liquid starts to deflate and it evaporates. This change of state extracts heat from the environment. It cools! A fan in front of the evaporator blows air around the many copper pipes. The air gets cooled down and can now transported to the area needing to be cooled.
The ideal gas law as the basis of Solar Cool
The basic of Solar Cool is the “The Ideal Gas Law”
p * V = n * R * T
The product of pressure (p) and containing volume (V) for the gas is proportional to its amount (n) and temperature (T). R stands for the gas constant and is a constant for the respective gas (here R410). That's a physical law and applies everywhere and always.
In order to understand Solar Cool we need to shift our perspective. Most descriptions starts with the compressor and follows then through all the other parts to explain the working principle. The ‘secret’ of Solar Cool lies in the expansion valve; when open its main objective is to allow the refrigerant to flow through faster than without Solar Thermal collectors.
When we start with the expansion valve and its impact on the previous components and keep in mind that we have a system with variable flows and not anymore fixed speed compressors, it gets clear looking at the "Ideal Gas Law":
p * V = n * R * T:
In the case of SolarCool, the volume (V) in the piping and subsequently the collectors remains the same, the gas constant (R) is stable. When the temperature (T) of the gas increases by 40°C, then either the pressure (p) goes up while the gas amount (n) remains the same, or the gas amount (n) goes down while the pressure remains stable. In the latter case, the gas pushed through the expansion valve inlet is significantly increased. Some know this effect as the tea kettle whistle effect. When the water boils, the vapour runs through the whistle of the kettle.
Scientifically: Water is heated up (T), the amount of water vapour in the kettle is reduced (n), while the pressure (p) and volume (V) in the kettle remain constant. This increased mass flow results at our air conditioners 1:1 in a higher capacity (cooling and heating) at the indoor unit.
On the occasion when the expansion valve closes for seconds, the pressure of the gas starts to build up until the valve is forced open again. In this case we see a pressure increase. Some may question that the higher pressure then acts negatively against the compressor. However this can only happen when the expansion valve is closed and the compressor keeps running. Typically the valve will only be closed for a matter of seconds, or even milliseconds, and this process has zero negative impact on the compressor due to the lengths of pipings and its resistances. When the valve closes for a longer period this is when the indoor unit no longer requires refrigerant to evaporate. In this case, after a few seconds the compressor and the whole unit logically shuts down, as no cooling is required.
The higher mass flow makes the compressor slowing down in a controlled way managed by the central logic. The control aims for a specific capacity at the indoor unit meaning a very specific mass flow rate. When the mass flow rate now increases due to the solar panel, the compressor slows down to re-achieve the targeted mass flow. That impact is massive, because the compressor makes up for 80% of the total power consumption.
It’s more than just compressors only. It’s the proper mixture of compressor, solar panel, thermodynamical system design and also very important, the logic of the central air conditioner controllers.
Wherever you are in the world and regardless of how much free sun energy is available - the fact is it will always come back to “The Ideal Gas Law”; if the temperature of a gas increases and the volumes are equivalent – mass flow or pressure increases.