What kind of cooler can I use on my work desk or small work space?

We are experiencing dramatic changes in the world’s climate. The temperature of most of the regions is getting increased. So we need a cooler at our work desk or air conditioning. Many people are working as freelancers either at their home office or desks in co-working spaces.  Unfortunately, most of us may not able to access a central or air conditioning in our workplaces- because either their expenses or technical details put an obstacle to access them in our small office rooms or communal offices.

However, we have alternatives in these tricky/challenging situations. Here the cooler for our work desk; A general rule of thumb for arid or dry weather air coolers and for humid and coastal weather air fans are cheaper and less hassle-free options compared to air conditioners (ACs) for your home office, small office and working desk.

What kind of cooler can I use on my work desk or small work-space?

Don’t expect cool air as ACs provides:

Operating costs for an air cooler are 1/10th of a traditional air conditioner:

What is the working system of Air coolers and fans?

Fans:

Air coolers:

An air cooler can actually lower indoor temperature by nearly 5℃

PROS:

Less expensive to install and operate

• Estimated cost for professional installation is about half or less that of central refrigerated air conditioning.^[28]
• The estimated cost of operation is 1/8 that of refrigerated air conditioning.^[29]
• No power spike when turned on due to lack of a compressor
• Power consumption is limited to the fan and water pump, which have a relatively low current draw at start-up.
• The working fluid is water. No special refrigerants, such as ammonia or CFCs, are used that could be toxic, expensive to replace, contribute to ozone depletion and/or be subject to stringent licensing and environmental regulations.

Ease of installation and maintenance

• Equipment can be installed by mechanically-inclined users at a drastically lower cost than refrigeration equipment which requires specialized skills and professional installation.
• The only two mechanical parts in most basic evaporative coolers are the fan motor and the water pump, both of which can be repaired or replaced at low cost and often by a mechanically inclined user, eliminating costly service calls to HVAC contractors.

Ventilation air

• The frequent and high volumetric flow rate of air travelling through the building reduces the “age-of-air” in the building dramatically.
• Evaporative cooling increases humidity. In dry climates, this may improve comfort and decrease static electricity
• The pad itself acts as a rather effective air filter when properly maintained; it is capable of removing a variety of contaminants in the air, including urban ozone caused by pollution^{[citation needed]}, regardless of very dry weather.
• Refrigeration-based cooling systems lose this ability whenever there is not enough humidity in the air to keep the evaporator wet while providing a frequent trickle of condensation that washes out dissolved impurities removed from the air.

CONS:

Performance

• Most evaporative coolers are unable to lower the air temperature as much as refrigerated air conditioning can.
• High dewpoint (humidity) conditions decrease the cooling capability of the evaporative cooler.
• No dehumidification. Traditional air conditioners remove moisture from the air, except in very dry locations where recirculation can lead to a buildup of humidity. Evaporative cooling adds moisture, and in humid climates, dryness may improve thermal comfort at higher temperatures.

Comfort

• The air supplied by the evaporative cooler is generally 80–90% relative humidity and can cause interior humidity levels as high as 65%; very humid air reduces the evaporation rate of moisture from the skin, nose, lungs, and eyes.
• High humidity in air accelerates corrosion, particularly in the presence of dust. This can considerably reduce the life of electronics and other equipment.
• High humidity in the air may cause condensation of water. This can be a problem for some situations (e.g., electrical equipment, computers, paper, books, old wood).
• Odours and other outdoor contaminants may be blown into the building unless sufficient filtering is in place.

Water use

• Evaporative coolers require a constant supply of water.
• Water high in mineral content (hard water) will leave mineral deposits on the pads and interior of the cooler. Depending on the type and concentration of minerals, possible safety hazards during the replacement and waste removal of the pads could be present.
• Bleed-off and refill (purge pump) systems can reduce but not eliminate this problem. Installation of an inline water filter (refrigerator drinking water/icemaker type) will drastically reduce the mineral deposits.

Maintenance frequency

• Any mechanical components that can rust or corrode need regular cleaning or replacement due to the environment of high moisture and potentially heavy mineral deposits in areas with hard water.
• Evaporative media must be replaced on a regular basis to maintain cooling performance. Wood wool pads are inexpensive but require replacement every few months.
• Higher-efficiency rigid media is much more expensive but will last for a number of years proportional to the water hardness; in areas with very hard water, rigid media may only last for two years before mineral scale build-up unacceptably degrades performance.
• In areas with cold winters, evaporative coolers must be drained and winterized to protect the water line and cooler from freeze damage and then de-winterized prior to the cooling season.

Health hazards

• An evaporative cooler is commonplace for mosquito breeding. Numerous authorities consider an improperly maintained cooler to be a threat to public health.^[30] 
• Mould and bacteria may be dispersed into interior air from improperly maintained or defective systems, causing sick building syndrome and adverse effects for asthma and allergy sufferers.
• Wood wool of dry cooler pads can catch fire even from small sparks.

Where are the best countries for air cooler uses?

Dry climate such as the west coast of America particularly Arizona, Nevada and Utah, Saudi Arabia and the southern (temperate) part of Australia, sometimes its use may be restricted in some parts of UK.

‘Several hot and dry regions throughout the world could potentially benefit from evaporative cooling, including North Africa, the Sahel region of Africa, the Horn of Africa, southern Africa, the Middle East, arid regions of South Asia, and Australia.’

If there sometimes are restrictions, should you still consider air coolers?

• “To integrate and offset mechanical cooling in high-temperature thermal load buildings when weather conditions permit
• To provide a low-cost comfort cooling option for non-air conditioned buildings for those summer days that don’t justify the installation of a mechanical cooling system”

What should you consider in an air cooler and fans tech specs?

Air Cooler

Parts of the Air Cooler

Control panel, cooling pads, water inlet, ice compartments (not in every model and not always as effective as it was thought to be. ‘The level of humidity and temperature of the atmosphere determine determines the coolness, not the ice. Therefore, adding an excessive amount of ice could potentially slow down the process of evaporation. This can hamper the air cooler’s efficiency.) hose connector, water tank.’

What to consider when buying the air cooler

When buying an air cooler, buy the ones that have a power rating between 130–230W.

The efficiency of an air cooler depends almost entirely on the heat-absorbing prowess of the cooling pads.

Cooling pads:

As a rule of thumb, cooling pads greater than 85 mm in thickness are effective enough in absorbing heat from the outside hot air.

(Thinner cooling pads are not as efficient as thicker ones because the lesser thickness and lesser overall area results in them not being able to retain as much water as the thicker ones so as to sufficiently absorb heat from the air. As a result, the air is blown inside the room still remains slightly warm, thus causing the users to feel warm and uncomfortable.)

Air coolers have two types of cooling pads: cellulose and the other, aspen/wood wool cooling pads. The former is usually in honeycomb shape even named as ‘honeycomb cooling pads’. They are expensive but highly durable. The latter is in shape of dried grass and have a texture like that of wood shavings.

Which are more economical with lesser efficiency. “Aspen Cooling pads are generally more affordable and easier to replace or install. Furthermore, they are more biodegradable and more effective compared to the synthetic versions, but the synthetic versions last longer;” said the ‘Vankool.’

‘Cellulose pads are also referred to as honeycomb cooling pads. Just like the name suggests, these pads actually resemble a honeycomb. These are thicker than Aspen Pads, have minimal maintenance needs and provide longer durability. While they might cost slightly higher, they are more efficient. As a minimum, they should preferably be 90 mm thick to enable them to provide more effective cooling of air.’

Water tank/ inlet:

• Hose Connector Some units come with a garden hose connector also known as an Automatic Water-level Controller. Through this connector, you can attach an ordinary garden hose to your unit. This will ensure there is a continuous and steady supply of water flowing to the cooler. This saves you the hassle of pouring water in the reservoir manually.
• Water Level Indicator In the case of there is no water level controller feature in the air cooler, it should include a water level indicator instead. If there is no automatic water level controller, you’ll have to fill the water holding tank manually. So, this water level indicator will show when enough water has been placed in the tank subsequently, minimizing the risk of leaking or flooding the floor by filling in too much water.
• Water Inlet and Drain Valve For optimal cooling, fill up the tank using a mug/water pipe through the tiny inlet. This is the easiest way to top up the water to the maximum level. The Drain Valve, on the other hand, enables frequent change of water to avoid mould and mildew growth.”
• You should be aware of the electric motor is in good quality in the air cooler model that you like to buy.
• With evaporative, it is about airflow and humidity. With humidity below 30% very effective, between 30% to 50% reasonably effective and above 50% humidity use refrigerated AC. Evaporative cooling works best with low humidity and if the temperature is < 40C.

Airflow

• Air cooler airflow is also measured by CMH(m³/h) (cubic meters per hour). The CMH means the amount of air cycled into your area each hour. It is a good way to buy the right air cooler size by calculating the CMH(m³/h) required for your place.
• The airflow also depends on a blower or a fan used by the evaporative cooler. Fans can create airflow with low pressure but in large volumes; they are usually used in big air coolers. On the other hand, Blowers can product high-pressure airflow at high volumes and often used to smaller air cooler models.
• While choosing an evaporative cooler, you should also find the models with multiple speed settings. It is one of the ways to adjust the temperature in the room by controlling the airflow; most portable air coolers with a 3-speed regulator at least. Except, the feature of automatic louvre movement is especially important for swamp coolers, it can ensure the flow of cool air in all directions.” 
• “Evaporative coolers’ cooling efficiency is rated in cubic feet per minute (CFM). To pick the right size cooler for your room, you must first determine how many cubic feet you need to cool. This is done by multiplying an area’s square footage by the ceiling height.

Example:

For example, a 250-square-foot room with an 8-foot ceiling has a cubic area of 2,000 feet (250 x 8 = 2,000). Then, you simply divide the cubic area in half (2,000 / 2 = 1,000) to find out how many cubic feet your evaporative cooler needs to be able to cool per minute. So, in this example, you would need a unit with a CFM rating of 1,000.” “To find the CFM, you’ll need the volume of the area and the recommended number of air exchanges per hour for a living room (typically six air exchanges per hour). Air exchanges vary by the type of space. Find a suitable air exchange per hour on this chart.

For example, if your living room is 420 square feet with 8-foot ceilings:

420 square feet x 8-foot ceiling = 3,360 cubic feet 3,360 cubic feet x 6 air changes per hour = 20,160 20,160 / 60 minutes = 336 CFM. – According to the equation, you would need a swamp cooler with at least 336 CFM for the size of your living room.

Here is a four-step process on how to calculate the room CFM:

1. First Step – Use the above Air Changes per Hour Table to identify the required air changes needed for the use of the room. Let’s say it’s a conference room requiring 10 air changes per hour.
2. Second Step – Calculate the volume of the room (L’xW’xH’).
3. Third Step – Multiply the volume of the room by the required room air changes.
4. Fourth Step – Divide the answer by 60 minutes per Hour to find the required room CFM.

So how to calculate CMH(m³/h) requirement of your Cooler with the example? 

There is a simple way to calculate. Just follow the example to calculate the CMH of the cooler.

Length of Room: 6 meters

Width of Room: 5 meters

Height of Room: 3 meters

Volume of the Room: Length x Width x Height = 6 x 5 x 3 = 90 m³

Number of times the air need to be replaced in an hour: 20 times The total volume of Air to be replaced in one hour: 90 cubic meters x 20 times = 1800 cubic meters per hour This is the CMH (cubic meters per hour) requirement for your cooler: 1800 m³/h So if the airflow of the single unit is 1800 CMH, you need one unit. Or if the airflow of the single unit is 900 CMH, you’ll need 2 units.

Tips on Performance:

Volume of the Room: Length x Width x Height = 6 x 5 x 3 = 90 m³The lower the relative humidity the better the performance of the cooler. Typically 70% are RH or below is good. • Cold or iced water does not make much difference to the cooling efficiency of an Evaporative Cooler. • Evaporative Coolers must only be used in areas with good natural ventilation or adequate mechanical air extraction units. Like humidifiers, it’s very important to clean your swamp cooler’s water reservoir or water pan regularly. If left to sit stale for too long, the water inside could become a breeding ground for mould, mildew, waterborne microorganisms, and other germs.

Cleaning- before summer

• Disconnect power from the unit.
•  Remove the weatherproof covers.
• Detach the filter pads, then clean them thoroughly using a hose and if necessary, consider replacing with new ones.
• Close the drains, then fill up the cooler unit with water.
• Disinfect your air cooler with a biocide. Avoid the chlorine-based bleach or other substances that help harmful organisms to thrive.

Cleaning-  end of summertime

• Disconnect power from the unit.
•  Loosen all forms of sediment or slime using a brush.
• Empty the pipes and the tank.
• Clean the cooler tank using a cloth drenched in household bleach and then, pump and flush it using freshwater.
•  Detach the cooler filter pads, including the hose. Then allow these components to dry.
• Dry all of the internal components.
• If necessary, consider fitting covers on every exposed component to avoid any form of damage.

Fan type vs blower type

Fan and blower are used for circulating and supplying air; however, technically they are quite different. The big difference between a fan and a blower is how the air is circulated. A fan is an electrical device to move air and the air around an entire room or a large area, on the other hand, a blower is a mechanical device t a blower is a mechanical device and moves the air to a specific location or point. In general, fans and blowers are used widely for cooling purposes in the industries. Also, both are widely used in electrical appliances such as evaporative air coolers, air conditioners, microwaves, and so on. They both produce air by the amount of pressure. Therefore, blowers can move lots of gas at a certain pressure while fans move largely of gas at a low-pressure.

In the following part, there is the comparison of brands.

What are the best AIR COOLERS for small/home office use?

If some of the products are sold out, you can find alternatives.