A solar air cooler works on solar energy. As the name suggests, it uses solar power to meet its energy requirements. Its operational mechanism is different from conventional evaporative air cooler and it better than solar air conditioner. The solar energy from sun is converted into chemical energy and stored in a battery. This battery then acts as the source of power supply for the cooler. Its simple mechanism and economical operation render it as obvious choice for almost everyone. It’s extremely useful for rural areas where there will be no electric supply.

1. Solar Air Cooler’s Working Principle

A solar air cooler makes use of the evaporative cooling mechanism. This is the most cost effective Eco-friendly and efficient cooling method. To understand the basic principle, imagine yourself coming out of the pool in peak summer. When the hot wind touches your body, the water droplets on your skin evaporate. This evaporation leads to reduction of surrounding temperature, thereby making you feel cool and comfortable.

When the cooler’s fan starts operating, outside hot air is sucked inside through the wet curtains (cooling medium). This hot air evaporates the water from the wet pads. The water evaporation reduces the temperature of the air by using up the heat. Therefore, the air blown out by the fan is fresh and cool.

Our in-house produced powerful cooling fans find great utility in several fields like industries, workshops etc. The solar cooler has gained lot of popularity due to its rugged, economical and environment friendly design. It has got an ever increasing demand in the USA, China, Europe, Africa, Middle East, Asia etc.

2 . Solar Cooler Vs Solar Air conditioner

 In order to compare solar cooler with an air conditioner, we should understand their basic principles. The following sub-paragraphs bring out the working principles and other relevant aspects for these appliances : 

The three types of solar air conditioner are as follows:

  • Solar thermal hybrid air conditioners

This type of air conditioner works on the principle of solar energy. The process of refrigeration is controlled by the compressor triggered by solar energy. The remaining electrical components and fans run by using electricity.

  • Solar PV hybrid air conditioners 

These air conditioners switch from solar energy to battery power and vice versa when required. In the presence of sunlight, the cooler takes advantage of the electrical source and charges it’s batteries. When sunlight isn’t there, it uses the charged batteries as a power source. Thus, it utilizes Alternate Current (AC) electricity.

  • Absorption chillers

The air conditioner operates on a heating and cooling process. Firstly, water is evaporated followed by condensation to form cool air. The fan and motor of the cooler are powered by solar energy. These chillers can operate on electricity as well as battery power whichever suits the situation.  

There are two types of solar coolers:

(1) DC Evaporative Coolers

This cooler uses a solar PV panel charged with battery for working. The DC 12/24 V solar air condition discharges the battery. When the battery is fully charged it can run up to 8, 12, 18 or 24 hours. In order to run off the grid, it requires a battery, a solar PV panel, and a charge controller.

This type of cooler has been designed specifically for places where there is no electricity. It can work 100% on solar power.

It operates directly on DC power without needing AC power or DC inverter. It is a purely solar-powered cooler. Solar power is a renewable and clean source of energy. This makes it a very eco-friendly and energy-saving device.


– Requires lower grid

-Cost of electricity is reduced

-Can be used in the absence of electrical power

-Greenhouse gas emissions are very less

(2)  AC/DC Cooler

 These air  coolers have the ability to switch between Photovoltaic Technology (PV) with Direct Current (DC). This means that they can use either solar energy or battery power as per the requirement. The system can charge its batteries by using electricity coming from sunlight. This occurs when the system is in hybrid mode. When this mode is turned off, energy is consumed from the back up in batteries. Simultaneously, it continues to charge the batteries via AC power.


– Dual power

– Priority to solar energy

-Dynamic adjustment


-Saves electricity

-Maximum working ability 95%

-Average working ability 70%

-Can be installed easily


-Reduces the cost and use of electricity

-No special installation required

-Keeps a dynamic proportion between solar power and regular electricity

-Can operate on electricity in the absence of solar energy

-Acts as a DC inverter to use electricity in the absence of sunlight

3 .What is the solar cooler Advantage and Disadvantages

The solar powered cooler has numerous advantages over the air conditioner and other air cooling systems. There are no disadvantages of the cooler, although it has certain limitations. All these are enumerated in the following sub-paragraphs :


The solar cooler is a great choice for almost all types of users. It’s ideal for areas where power cuts are frequent or where there’s no electric power. Being available in various sizes, it suits industrial usage as well as individual household use. Some of the most noted benefits of the Solar cooler are :-
  • It uses solar energy and has minimal running cost.
  •  It saves electricity and has no carbon footprint, which makes it highly Eco-friendly.
  •  It’s easy to use and handle with simple design.
  •  With simple and cheap components, it has very less maintenance expenses.
  •  It’s initial cost is quite low.


The only limitation of the solar air cooler is its dependence on solar energy. This makes it likely to be affected by weather conditions. It can not be used effectively in cloudy conditions. But then, you don’t generally need a cooling system in overcast weather.

4. Where is the solar cooler application 

 It can be used in the rural areas where power cut is a problem.

Área de aplicação de climatizador evaporativo

5.What is solar cooler Features

Solar Panels

A solar panel is a type of grid that produces electricity by using energy coming from the sun. It is a renewable source of energy. It is not only eco-friendly but also increases property value and keeps our environment clean.
The composition of a solar panel includes individual solar cells. The positive charge is provided to the cells by layers of silicon phosphorous. The negative charge is provided to the cells by layers of boron. These panels absorb the photons found in sunlight and trigger the formation of electric current. When photons strike the surface of the panels, energy is produced. This energy knocks out electrons from the orbits releasing them into an electric field. These free electrons are then pulled into a directional current. This process of energy generation via solar panels is called Photo Voltaic Effect.

Charge Controller

A charge controller or a battery regulator regulates the current flow. By controlling current flow into the battery, overcharging is avoided, thereby enhancing battery’s performance and providing safety. It also avoids complete discharge of the battery and hence increases its life. A charge controller may be either a stand-alone device or an internally integrated circuit within the battery-powered equipment. There are terminals with screws at the base of the solar controller. These terminals are marked with positive (+) and negative (-) signs for ease of identification.

Note : It’s very important to have proper connections. The polarity should be correctly joined keeping the +/- terminals in mind. Incorrect battery connections may lead to damages to the appliances, solar panel or the battery. Following steps should be taken to ensure proper connections :
Step 1 : Battery Connection
Connect the battery to the charge controller using suitable cables. It is recommended to connect a fuse near the battery’s positive (+) terminal.
Step 2 : Solar Panel Connection
Ensure that the solar panel and the battery are of the same voltage. Study the specifications and manufacturer’s guide before commencing connections. There are clearly marked ‘SOLAR PANEL’ terminals on the solar controller. Connect the solar panel to these terminals using appropriate cable as per manufacturer’s directions. Before switching on the circuit, check that the solar panel is correctly connected. This can be done by scrolling through the settings to view input voltage of solar panel.
CAUTION : Solar panels always generate electricity when exposed to the sun. So, handle these with care even when disconnected. If the connection gets completed accidentally, electric shocks may result. It may cause serious injuries to handlers or may result in fire. It’s therefore highly recommended that the front portion of solar panels are covered during installation. They may be covered using some soft cloth to block sunlight to avoid current generation.
Step 3 : Solar Cooler Connection
The final step is the connection of the solar cooler to LOAD terminals of the solar controllers.

PMDC Motor


Permanent Magnet DC (PMDC) motors were first introduced in the 19th century, but were not widely accepted. The main rea
son for this was the poor quality of magnetic materials like tungsten steel available at that time. This put a limitation on the efficacy of the PMDC motors. This diverted the motor designers of that era towards motors in which electromagnetic fields were used for excitation. Thus electromagnetic motors acquired the centre stage of all new developments until recently. Advancements in magnetic technology demonstrated improved power density and steady state performance of PMDC motors. There has been a sharp increase in the demand of these motors in the global markets. PMDC motors are widely being used in various appliances like medical instruments, office equipment, computer peripherals etc.

There are numerous benefits of the PMDC motor over its DC counterpart. Five of the major advantages are as under :

  • Higher efficiency. Unlike a DC motor, in which electricity is used to maintain a magnetic field, there are no losses in a PM motor. This means that the PMDC motor has a higher efficiency.
  •  PMDC motor has higher torque power density.
  •  The motor has more predictable characteristics because of linear torque speed.
  • PMDC motor has higher magnetic flux density in the air gap due to its permanent magnet. This enables it to have better dynamic performance.
  • Simple design of PMDC makes it easy to maintain.

6.How much do the solar evaporative cooler lower the temperature

Being a solar powered cooler, it’s generally good for all as it saves electricity and is Eco-friendly. However, an evaporative cooling system works best in areas having low relative humidity. It’s known to lower the temperatures to around 20 degrees Celsius. It’s cooling efficiency goes down with increasing relative humidity. You must therefore check the relative humidity of your area during summers before buying it. As a thumb rule, if the air produced is cooler than 70 degrees Fahrenheit, the cooler will be useful. If the air produced is hotter than 75 degree Fahrenheit, it won’t be of much use. 70-75 degrees Fahrenheit is the range in which some people will feel comfortable, whereas, the others may not.

Portable Evaporative Cooler

7. How to connect ac/dc Solar Air Cooler 

It is important to connect correctly to enjoy the max cooling efficiency of the evaporative cooler. Here a video to teach how to do it . There are Four ways to run the air cooler :

way#1. Work with Battery 

way#2.Work with AC power

way#3.Work with Solar Panel 

way#4.Work with full set solar system

8.How to Calculate solar air cooler running time

Solar air cooler

Here our cooler load voltage is 12V and the total wattage is 120.

Battery capacity is 12V, 100Ah

Solar panel is 18V,200 W

Solar cooler running time = Battery current(A)/ Solar panel current(A)

Solar panel current(A) =watt / volt

Time need to charge only by solar=100/(200÷18) = 9 hours

So the solar air cooler running time is 9 hours

Note: Combination of external sources and solar panel will reduce the charging time. (All assumptions are made neglecting all losses)

9.How to Calculate the Payback for solar cooler

 Payback is defined as the amount of time in which our product becomes free

Let’s suppose that:

The full set of solar cooler including solar accessories is USD400, We will use 8 hours per day and use 120 days per year,The electricity charge is USD0.15/Kw-hour


If we use air conditioner to cool the space, it will take us 8*120*1*0.15=USD144 per year


We use solar air cooler instead, we will get the money back in 2.78 years (400/144)

It means that after 2 years and 284 days,you will get all your money back and you own the solar air coolers for free after that. Moreover,it will keep saving electricity bills for you after that time. 

Note: If we use air conditioner to cool the space instead of solar air cooler,we might need 1 Kw/h electricity

10.Top tips to choose the right solar air cooler brand

Low price, minimal operating costs and cheap maintenance make solar cooler an affordable choice for all. It’s excellent for rural and backward areas where electric supply is not there. It’s a favorite in schools, houses, offices and workplaces in areas of frequent power cuts. It cools down the room temperature to a comfortable 20-25 degrees Celsius with relative humidity of 60%.

For any dealer wishing to buy the coolers in bulk, choosing a manufacturer with the most competitive prices is recommended. Vankool is a superb choice for those in the wholesale business. It is the preferred OEM dealer for Honeywell for the past 12 years.

Vankool who can meet such requirements and will be a good choice when you consider to choose a window swamp coolers manufacture in China.  Here 6 more reasons that why Vankool could be a good choice for you:

– Over 12 years experience in the field of evaporative air coolers

– Vankool OEM supplier for Honeywell for more than 12 years.

– Over 5 new air coolers will be designed for customers by ODM service

– With full range of evaporative air cooler products like portable air coolers (residential and commercial), window air cooler, industrial air cooler

– ISO 9000 QC standard will be applied for each order

– Short delivery time for sample order (1-2 days) and bulk order (15-25 days)