Early summer usually provides a pleasant respite from the frigid winter. But in April and May, the summer heat begins to take its toll physically and mentally. As in much of Pakistan, hot days can be stressful in tropical climates. Lowering individual energy levels and lowering productivity.
That’s when modern air conditioners appear as a gift from heaven. Too many offices, laboratories, hotels, and public buildings are now equipped with air conditioning systems. The central air conditioning system ensures that every corner of the workspace is cool.
It all sounds crazy, but it isn’t. Bulky central air conditioner installation is synonymous with a lot of energy consumption (and waste). This leads to high electricity bills and horrifying blackouts. The next step of course is the DG. It provides much-needed comfort indoors while exhaling a cloud of black smoke. With a very high level of noise pollution for the outside world and the environment to carry.
While defending ourselves against nature’s wrath, we attack nature more and more. Nature then returns more and more intensely. Therefore, one of our biggest fears is the imminent danger of global warming.
So what must we do to survive and survive comfortably?
Remember that the sun we protect ourselves from has a tremendous source of energy. One of the answers is to use solar energy to generate electricity. It’s free and you can safely assume it’s unlimited right now. Yes, solar energy can light our homes and cook our food, but it keeps our homes cool, so is that possible? The revolutionary technology of the future, solar air conditioning is the solution.
Solar Air Conditioning is achieved when an air conditioner uses solar power to work. Liquid or gaseous substances accumulate on the surface of porous solids (adsorption). Or are absorbed into the liquid. Or solid substances (absorption to provide the necessary cooling). Some operations operate on the air conditioning directly. That is, it is processed concerning temperature and humidity.
Thermal-driven refrigeration and air conditioning are at the heart of all solar cooling systems. The main principle of absorption-assisted air conditioning is shown in the diagram here. Solar energy is used to remove moisture from adsorbents.
The Nine-Step Process
- From the first stage to the second stage. The temperature rises due to the heat of absorption released at the same time as the removal of moisture from the outside air.
- In stages 2 to 3, the air is then cooled in the opposite direction with the exhaust in a rotor for heat regeneration.
- In stages, 3-4The air is further cooled by evaporative humidification. So, the air entering the building has a lower temperature and less water vapor than the air outside.
- Stages 4 through 5 heat the air and add water vapor as needed.
- In stage 6, evaporative cooling of the humidifier lowers the exhaust air temperature.
- In stages 6-7, this exhaust is counter-heated to the air entering the heat recovery rotor. The exhaust is additionally heated by an external heat source (eg a solar thermal system).
- Finally, in stages 8-9, the adsorption rotor regenerates the adsorption of bound water.
Open Circular Air Conditioning System:
Open-cycle systems are most effective in buildings with high moisture loads and high air exchange rates. Supply, return and heat recovery air ducts are required to be installed. In this case, moisture is removed from the outside air by absorption. The room is conditioned to the desired temperature by heat recovery and direct and indirect evaporative cooling. Usually, dehumidification is performed with a rotator containing silica gel or lithium chloride. These systems require solar heat to regenerate the absorber/absorption units.
Closed cycle dryer evaporative cooling systems can be either adsorption (using a solid desiccant such as silica gel or zeolite and water as coolant) or adsorption (if the dryer is a liquid, lithium bromide as the desiccant and water as the coolant). for material pairs). or water as desiccant and ammonia as coolant, sub-zero temperatures may be required).
Only Solar-powered processes are used to cool and acclimatize the building
In practice, solar heat collectors convert solar radiation into heat. To fuel heat-driven cooling processes or natural air conditioning processes. Photovoltaic generators convert solar radiation into solar energy to drive the cooling process. Especially in special applications such as pharmaceutical cooling at remote off-grid sites. This is usually done in the form of a pressure coolant. Significant advances have been made in solar heating and cooling. The technology is rapidly being tested and approved all over the world.
Solar air conditioning performance
Important points to consider when designing a SAC system and judging its performance are the load profile, outside temperature, and humidity.
The determination of whether solar cooling is suitable is influenced by the load profile. The use of fossil fuels to power the cooler is inappropriate. From this point of view, primary energy should be avoided. So solar radiation must be linked with the demand for cooling.
To achieve the highest possible use. Consideration should be given to applications that require heat to heat water outside of the cooling season. Or for heating systems. Therefore, apartment buildings and small office buildings are best suited. When cooling is required year-round (process cooling, server rooms). Solar cooling systems can only be used as a fuel saver for conventional air conditioning. In such cases, free direct cooling via a heat removal unit may be an option in the cooler months.
How Does It Work?
The rate of heat removal greatly affects the performance and efficiency of the coolant. In most systems, waste heat is released into the environment. It happens through dry coolers or wet cooling towers. The first is suitable for temperate climatic zones with occasional high external temperatures. Wet cooling towers can provide cooling water temperatures below ambient temperature. But, it only works when the relative humidity is high and evaporative cooling is possible. It is also not suitable for areas where water is scarce. In addition, some countries impose strict sanitary regulations on wet cooling towers. This makes the operation of small systems economically impractical.
It is necessary to be aware of the fact that boundary conditions other than nominal conditions can adversely affect the performance of the coolant. If the system is not designed for the nominal operating point. The relevant operating data must be requested from the manufacturer. Then, for example, dry reverse cycle coolers can also use in temperate climates if the solar thermal system is properly adapted.
Efficient use of EC motors in SAC settings helps reduce power consumption. To further reduce energy consumption. It should be controlled according to operating conditions and cooling demand. Other methods of eliminating waste heat are possible, depending on local conditions. Through wells, ponds, or groundwater. Ideally, the heat can be used elsewhere.
Advantages of solar air conditioners
There is no solar cooling compared to traditional electric pressure cooling technology advantage. These systems are very useful in the summer when the sun is shining. The machines generally use environmentally friendly refrigerants, which reduce greenhouse gas emissions. Non-greenhouse water is more often used compared to the refrigerant used in pressure coolers. If these systems are designed properly, significant energy savings result. The fact is that they only require supplemental energy to operate the pump. Besides cooling, solar collector systems can also provide thermal energy. This supports local hot water supply and heating, further reducing emissions. SAC is also ideal for hotels, supermarkets, schools, factories, and large office facilities.
Therefore, solar-based AC systems can offer a reasonable alternative to conventional AC. In addition to significantly reducing or eliminating existing air conditioning bills. Many areas can get huge cash rebates and tax credits for powering their air conditioners with solar air conditioning systems. Capital investment is currently high, but the system can justify its value in the long run. It is only a matter of time before this technology is mass-produced. If it happens costs will reduce to levels that are reasonable for the common man. , it will be the same day when the maximum amount of energy can be extracted from the sun. The choice is ours!