As the chillness of the winter months withers down to give way to a balmy and colourful spring, one often tends to idealize the climate of one’s place. However, this relief is often short lived as the hot and humid summer that follows already has something else in store for us. As summer begins to roar and temperatures start to soar, moving out in the sun seems to be a daunting task. But, there is not much respite in staying inside either. The discomfort and uneasiness caused by the heat often leaves one completely drenched in sweat and averse to summer even when one is within the confines of the four walls. In such scenarios, an external cooling source is required to ward off the high temperatures and to facilitate an environment conducive to proper functioning of the human body.
This is when an air cooler comes to the rescue…
An air cooler serves the sweet spot between the comfort provided by a regular ceiling fan and a heavy duty air conditioner, both in terms of initial cost as well as recurring expenditure in the name of electricity bills. Hence, it is one of the most sought after home appliances.
Now, if you are a frequent visitor to the posts on this blog, you might be probably aware that we take each topic from the grass root level and we will do the same with this post as well. We will begin with the basics first, understand how an air cooler works. Then, we will discuss the different types of air coolers available in the market along with the advantages and disadvantages of each. Following which, we would analyse some important aspects of air coolers that one should keep in mind before buying one. Next, we will proceed onto discussing how some brands try to cut manufacturing costs and manufacture below par products that have a very short shelf life and require frequent service. After which, we will move onto deciding which are some of the best air coolers available in the market that are not only efficient in adequately cooling the space but are also made of high-quality and durable components, thereby offering the most value for one’s money.
You might be glad to know that my father works at a company that manufactures home and kitchen appliances like washing machines, refrigerators, air coolers, vacuum cleaners, etc. So, at home, we frequently have a conversation about these appliances, what goes into making them, how some brands try to cut manufacturing costs to increase their profit margin etc.
Today, I will try my best to pass on the knowledge that I have acquired from my father over the years, to you so as to help you make a good buying decision.
So without further a do, let’s begin…
An air cooler is an appliance that works on the principle of imparting chill to the air by evaporation of water. Due to this fact, air coolers are also known by the name ‘evaporative coolers’ in some places. Evaporative cooling is based on the fact that water absorbs a large amount of heat in order to evaporate. The temperature of air drops significantly when phase transition of water from liquid to vapour state takes place.
This method of cooling the air takes much less energy than the principle of refrigeration used in air conditioners. Lesser energy consumption translates into lesser electricity bills, thus higher savings. In dry climates, evaporative cooling also provides an additional advantage of enhancing the moisture content of air, thereby providing added benefits to the consumers.
Hot air from the surroundings is pulled inside the air cooler where it passes through moistened pads. A water tank situated at the bottom of the air cooler provides continuous supply of water to the pads. An electric pump fitted inside the air cooler is responsible for taking streams of water from the water tank up towards the cooling pads and moistening them. The moist pads absorb heat from the air which results in evaporation of moisture from the cooling pads, thereby cooling the air by as much as 8 – 12 degree celcius and enhancing its moisture content. The cool and moistened air is then recirculated by the means of a fan driven by an electric motor into the environment which lowers down the surrounding temperatures and provides comfort to those nearby.
(Image of working of an Air Cooler)
Air coolers are primarily manufactured in three configurations:-
- Personal Air Coolers
- Desert/Window Air Coolers
- Tower Air Coolers
Personal Air Coolers
As the name suggests, personal air coolers are mobile air cooling appliances that can effectively cool areas up to 200 square feet and can be moved to any location within one’s house as per requirement. Due to the relatively smaller area personal air coolers can cater to, they are best suited for bedrooms and/or medium sized living rooms. Castor wheels are attached to the bottom of the frame of the air cooler which help to increase the maneuverability quotient of personal air coolers and thus make them very versatile devices ready for being put to use right out of the box. Due to their small form factor, personal air coolers have a limited capacity water storage tank, so in some cases, one might find the need to refill the tank twice a day.
Desert/Window Air Coolers
This category of air coolers is very popular among buyers for the fact that its cooling prowess is not limited to just one bedroom or a small living room, but to areas in excess of 550 square feet. Therefore, just one desert air cooler is sufficient enough to adequately cool a major section of one’s home. Desert air coolers are also known by the name ‘Window air coolers’ for their place of installation being a window, just like that of window air conditioners. Unlike personal air coolers, desert air coolers need to be installed by a skilled technician filling the gaps and crevices by a suitable material created as a result of removal of glass pane from the window and installation of the air cooler in its place.
(Image of a desert air cooler being used outdoors)
Tower Air Coolers
Tower air coolers are by and large quite similar to personal air coolers both in terms of maneuverability as well as the effective area they can efficiently cool, but with the added benefit of an even smaller form factor and a more aesthetically pleasing form factor as compared to personal air coolers. Since tower air coolers are more tall than wide, they take even lesser space on ground than personal air coolers making them an ideal choice for homes where space is a little constrained.
Now, having learnt about the three types of air coolers along with the effective area each of them can efficiently cool, let us proceed to discuss the advantages and disadvantages of air coolers.
- Low energy consumption. A typical 1.5 ton window air conditioner with 5 star energy rating consumes approximately 1.4 – 1.8 units of electricity per hour. Whereas, a desert cooler consumes a measly 0.2 – 0.5 units of electricity per hour. Assuming both the appliances run for 8 hours a day, one would be able to reduce the energy consumption by about 40 per cent, which would result in significantly lesser electricity bills.
- Little to no maintenance. Apart from annual replacement of cooling pads, which again are relatively inexpensive, air coolers do not require any other kind of maintenance. Hence, unlike air conditioners which require to be thoroughly cleaned each season before they can be brought into operation, air coolers can be brought into use as per one’s wish by only having installed a fresh set of cooling pads.
- Dual purpose. Since air coolers work on the principle of evaporative cooling, the phenomenon entails that apart from cooling the area, moisture and humidity levels of the surrounding air are also enhanced. The results are somewhat comparable to the cool-moisture rich breeze one would feel standing beside a waterfall. Therefore, regions that are predominantly dry, where the surrounding air has little moisture content would benefit significantly from the dual characteristics of air coolers. Even in coastal and other relatively humid regions, air coolers make for a great proposition in the months preceding rainfall.
- No use of refrigerants. Unlike air conditioners that rely on refrigerants like Hydro-Chloro-Fluoro-Carbon (HCFC) or Hydro-Fluoro-Carbon (HFC) to provide necessary cooling, with air coolers it’s just air and water. Those sophisticated odourless refrigerants that find their application in air conditioners, upon accidental leak might prove to be harmful to humans if inhaled. Additionally, refrigerant leaks are a major cause of ozone layer depletion, and global warming in general.
- A little noisy. Since air coolers make use of a fan/blower to throw a cool breeze of air into the room, the functioning of a moving fan is often not pleasing to the ears. Additionally, other components of the air cooler such as the electric motor and the electric pump also contribute their bit to the already noisy environment, however with time, one gets used to the sounds but those who prefer to have an utmost peaceful home environment might not find air coolers to their liking. In such case, air conditioners make for a better alternative since they offer a quieter and often noiseless operation.
- Not very effective in humid conditions. As stated before, air coolers work best when surrounding air is dry. Typically, the humidity level up to which air coolers are most effective is below 65 per cent. If humidity level is higher, the additional moisture created in the home by the air cooler would only add to the uneasiness and overall discomfort in breathing. In such a scenario, using an air conditioner may prove to be the only source of respite.
- Continual monitoring of water level. As the entire operation of air coolers relies on availability of water in the storage tank, one has to periodically replenish the water in the tank. Furthermore, loading water in the tank is itself a chore as one has to unload several buckets of water depending upon the water tank capacity or connect a hose pipe to the inlet port of the water tank, then keep a watch on the water level and disconnect the hose pipe before the tank overflows. In view of the same, if one is more inclined towards a hassle free appliance that does not require recurring monitoring again, an air conditioner makes for a wiser choice.
So, having analysed the Pros and Cons of owning an air cooler, let us proceed to examine some of the important aspects of air coolers that one should keep in consideration before buying one:-
IMPORTANT POINTS TO CONSIDER
- Power rating. For most homes, an air cooler with power rating between 130 – 230 W would make for an ideal choice. Power rating lesser than 130 W would result in relatively less cooling, and greater than 230 W would ensure excellent cooling, but would entail higher energy consumption which would result in higher than expected electricity bills. Therefore, power rating between the mentioned range would ensure a perfect balance between effective cooling and energy efficiency.
- Types of cooling pads. Primarily, cooling pads of air coolers can be made from two materials – Cellulose or Wood shavings/synthetic fibre. The cooling pads that make use of cellulose have an appearance as that of honeycomb and are appropriately named as ‘honeycomb cooling pads’. This category of cooling pads is highly durable and highly efficient, and in most cases requires replacement only once in two seasons. However, these are costly in nature, typically thrice as costly as the second type of cooling pads called ‘aspen/wood wool cooling pads’. Aspen cooling pads have an appearance as that of dried grass and have a texture as that of wood shavings. These cooling pads are relatively less efficient than honeycomb ones, but are very economical. As a result, air coolers that make use of aspen cooling pads are relatively less pricey as well.
(Image of honeycomb cooling pad)
Now, having examined what one should keep into perspective before buying an air cooler for one’s use, let us proceed to understanding the ways in which some manufacturers (names not taken) try to cut manufacturing costs in order to maximize their own profits and in turn deliver a sub-standard product to the customers, the components of which have a very short shelf life and may require frequent servicing.
COST CUTTING TECHNIQUES
- Low-grade overheating electric motor. The electric motor rotates at high RPMs to power the blower/fan that throws cool moistened air into the surroundings. This makes the electric motor one of the most crucial components of the air cooler and therefore accounts to almost 30 per cent of the entire cost of the product. Hence, it is one of the favourite areas of some manufacturers to cut costs and increase their profit margins. Some manufacturers resort to using a below-par electric motor that is not powerful enough to keep the fan rotating at high speeds for long periods of time. After only a few minutes of use, these electric motors tend to get extremely hot. As you might be aware that metals expand on heating, which causes the copper windings in the motor to initially distort and then finally melt, thereby leaving the air cooler unit out of operation. Cost of repairing the motor might range from a few hundred bucks to more than a thousand bucks and this process is recurring.
- Inefficient cooling pads. Cooling performance of an air cooler is a result of the material used in manufacturing the cooling pads as well as their thickness. As a rule of thumb, cooling pads having thickness greater than 85 mm are most effective in sufficiently cooling the space. Thicker cooling pads also last longer than their thinner counterparts and require less frequent replacement. However, thicker cooling pads are a little costly, so in order to cut production costs and to reduce the overall cost of the product so as to lure innocent customers, some manufacturers resort to using thinner, poorly fabricated cooling pads, the cooling prowess of which is inadequate, which often results in leaving the users feeling uncomfortable and uneasy despite the air cooler being in operation for a long time.
Now, having learnt how some manufacturers cut costs, let us proceed to zero down on some of the best air coolers available in the market that not only offer efficient cooling capabilities, but are also made of components that offer reliable and long-lasting service, thus providing most value for the money spent.