Evaporative cooler

Types of evaporative coolers

An evaporative cooler, also known as a swamp cooler, is an air conditioning system that cools the surrounding air through the evaporation of water. Industrial evaporative coolers were designed for people who wanted fresh, breathable, and cool air while also keeping energy consumption low. Below are some common types of evaporative coolers:

• Ducted evaporative coolers: This type of cooler provides a central cooling system ideal for larger open-plan spaces or multiple rooms. Ducted evaporative coolers draw air into the home through vents, which is then cooled, and subsequently distributed through ducts to various parts of a home or commercial facility. The amount of cool air ducted will depend on the size of the cooler and the ducting system. Using this method means that one single central unit can provide cool air to different rooms simultaneously, which in some cases may be more efficient than using multiple individual coolers.
• Desert evaporative cooler: Also known as direct evaporative coolers, desert evaporative coolers work by pumping water onto a soaked pad where a fan is then used to pull hot, dry air from outside the home or facility through the wet pad. The process of water evaporation from the saturated pad then humidifies and cools the air before the cool air is channeled into the room or space. Direct evaporative coolers are highly effective in dry arid desert-like climates.
• Industriial evaporative cooler: An industrial evaporative cooler is a larger-scale cooler built to occupy and cool larger, typically more open space areas. Such coolers include swamp coolers, portable coolers, ducted coolers, and other types that adapt to different industrial settings and applications. Usually, industrial evaporative coolers will be fixed to walls, windows, or ceilings for the purpose of constant overhead comfort cooling. Ideally, an industrial evaporative cooler aims to provide a cost-effective and environmentally friendly alternative to conventional air conditioning systems. Furthermore, they offer high cooling capacity, which is enough to meet the demands of industrial facilities. They are simple to install and operate and low maintenance. Industrial evaporative coolers also have the advantage of being energy-efficient options for large-scale cooling solutions.
• Indirect evaporative cooler: Between direct evaporative coolers and indirect evaporative coolers lies a more complex cooling technique. Indirect evaporative coolers function by making use of the evaporation of water to cool the air stream without adding moisture to the cool air. This is particularly useful in humid climates where the efficiency of evaporative cooling is reduced. In straightforward terms, when water evaporates, it absorbs heat from the air. This causes a drop in temperature, which cools the air. Indirect evaporative coolers cool the air indirectly through heat exchangers. The heat exchanger cools and dehumidifies the air before it's sent into the room. This also makes the indirect cooler more efficient when used in high humidity areas.
• Portable evaporative cooler: Unlike swamp coolers, which are permanent fixtures that are fixed into place, a portable evaporative cooler is a movable machine that is rolled or picked up and positioned wherever cool air is needed. Most portable evaporative coolers come with castor wheels for easy maneuvering from one location to another as needed. Portable evaporative coolers are also great temporary and affordable alternatives to air conditioning units.
• Powerful evaporative cooler: Depending on the manufacturer and retailer, an evaporative cooler may be denoted as powerful or not. Generally speaking, a powerful evaporative cooler is one that offers high airflow and cooling capacities. In general terms, the higher the CFM, the larger the space the cooler can occupy. The higher the cooling power, the more water the cooler will use per hour.

Specification & maintenance of evaporative coolers

Some typical specifications associated with an evaporative cooler are as follows:

• Cooling capacity: It indicates the amount of heat that the cooler can remove from the air. The cooling capacity is often measured in BTUs or watts.
• Airflow rate: It indicates the amount of air that the cooler can move. The airflow rate is often measured in cubic feet per minute (CFM).
• Noise level: It is typically measured in decibels (dB). Different models of evaporative coolers have different noise levels.
• Water consumption: It is the amount of water that the cooler uses to operate. It is typically measured in gallons or liters per hour.
• Energy efficiency: It may be presented as the power consumption of the cooler, which is typically measured in watts. An evaporative cooler's energy efficiency and power consumption depend on its design, operating settings, and environmental conditions.
• Dimensions and weight: Some portable evaporative coolers and swamp coolers for homes are designed to be lightweight and compact so that they can be removed and relocated easily. Among the dimension and weight, storing space will be an important factor.

Appropriate maintenance can keep evaporative coolers working well. Regularly cleaning or replacing water pads is a crucial part of the cooler. It can prevent the growth of molds or bacteria and allow the cooler to work at optimal levels. Another important maintenance task is to clean the water tanks. It not only allows the water to flow smoothly but also extends the service life of the cooler. Part of the process of maintaining an evaporative air cooler is to wipe its outer surface to prevent it from getting too dirty quickly. Last but not least, the cooler should be stored in a dry environment when it is not in use so that moisture does not enter it and damage its internal parts.

Applications of evaporative coolers

Industrial and commercial: Large-scale evaporative cooling systems are often used in factories, warehouses, and workshops. They're a cost-effective way to cool big spaces with lots of people and equipment. These systems improve work efficiency and comfort. Other commercial spaces like hotels, restaurants, and shopping malls also want more affordable ways to keep customers comfortable. Large evaporative coolers or centralized systems can meet this demand.

Greenhouses and farms: Greenhouses have to strike a balance between adequate ventilation and keeping humidity levels high enough to benefit plant growth. An evaporative cooler can provide a comfortable growing environment while reducing the risk of fungal diseases caused by low humidity.

Livestock ventilation systems are designed to remove excess heat, moisture, and gases from the animal housing. The primary purpose is to enhance animal welfare, performance, and productivity while minimizing the transmission of airborne pathogens.

Although livestock ventilation systems are primarily concerned with preventing pollution, they are mostly evaporative coolers. Cages can be kept reasonably cool in hot weather by using a system that removes heat and humidity from them.

Semiconductors and data centers: Data centers and semiconductor factories place a premium on precise control. Data centers need to manage heat generated by servers while also guarding against problems like corrosion, fungal growth, and electrical malfunctions. The semiconductors must be kept precisely within a highly controlled cleanroom environment. Because of this, the evaporative coolers used in these places are special to meet their distinct needs. They have features like anti-corrosion design, low humidity, high-efficiency filtration, and easily cleanable components.

Food processing: A few examples of the generally accepted design principles for evaporative coolers at food production plants are that they shouldn't consume extremely chilled water and should be placed close to workstations instead of whole rooms. Additionally, food-grade lubricants and materials should be used in their moving parts, and electric motors should be totally enclosed.

Residential: Small evaporative coolers are a low-cost option for cooling small spaces. They work best in dry climates where humidity is usually below 50%. Portable coolers are great for tents and RVs during summer camping trips.

How to Choose an Evaporative Cooler

• Climatic Conditions:

  Opt for an evaporative cooler if the area experiences high temperatures and low humidity. Besides coolness, it adds moisture to the air, which is beneficial in dry climates. Consequently, it can prevent problems such as dry skin, mucus membranes, and scratched throats.

• Room Size and Coverage:

  Consider the room size and coverage that one needs to cool. Look at the cooler's airflow rating, which is in cubic feet per minute (CFM). This means how much air the cooler circulates. Choose a cooler with a CFM rating that matches the square footage of the room. A general guiding technique is to have 1 CFM for every square foot of the room.

• Cooling Pads:

  Opt for a cooler with quality cooling pads. The devices use evaporative cooling pads to absorb water and let air pass through them. Choose the cellulose pads over the aspen ones since they are more efficient. Cellulose paper is more rigid and offers greater surface area. They also perform better, last longer, and are more hygienic. In addition to that, they consume less water and allow more air to go through them.

• Energy Efficiency:

  Check the cooler's energy efficiency rating. Higher ratings mean lower energy usage. Compare the power consumption of different models to find an efficient cooler.

• Noise Levels:

  Consider the cooler's noise levels, especially if it will be in a bedroom or quiet place. Check the decibel levels and choose a model that operates quietly.

Evaporative cooler FAQs

Q1: How much humidity is required for an evaporative cooler to work?

A1: There is no specific humidity requirement for an evaporative cooler to work. However, the evaporative cooler works best in low-humidity environments. Higher humidity levels may reduce its cooling efficiency.

Q2: How many hours can an evaporative cooler run continuously?

A2: An evaporative cooler can run continuously for 8 to 12 hours daily. With regular maintenance, the evaporative cooler can be used daily for several years.

Q3: Can an evaporative cooler be used in a closed room?

A3: Yes, an evaporative cooler can be used in a closed room. However, the cooling performance may not be as effective due to constant water evaporation in the air. To achieve optimal cooling, it's important to allow some air circulation in the room.

Q4: Can an evaporative cooler cool an entire house?

A4: It depends on the size of the evaporative cooler and the house. A whole-house evaporative cooler can be used to cool the entire house. For smaller evaporative coolers, the performance may be limited depending on the size and space.