Does Your Evaporative Media Need to be Changed?

If you want to escape the heat in summer, then evaporative coolers are an effective way to chill the air in dryer conditions.

They are, unfortunately, not as effective in more humid environments. But you can improve their cooling capabilities by ensuring that they are operating correctly and are regularly cleaned.

A critical component in any evaporative cooler is the evaporative cooler media. 

The cooling pads are designed to allow the cooling media to soak up water and at the same time allow air to pass through. It is the passage of air through the water-soaked cooling media that causes the water to evaporate, chilling the air.

However, over time (usually 6-12 months), the cooling media deteriorates due to impurities in the water, high pH levels as well as from physical damage, dust, pollen, and other wind-borne debris.

Once the evaporative cooler media becomes damaged, the efficiency of your evaporative cooler diminishes, and it is unable to perform to the same level as before.

Here are some of the things you should be looking at as part of your routine maintenance of evaporative coolers.

Look for Signs of Softened Media

Evaporative coolers come in a variety of shapes and sizes and are designed for very different tasks. The evaporative media in each type also varies based on the size and usage of the unit.

Households that require a small 300 square foot or smaller room cooled, can make do with a smaller, portable evaporative cooler. Whereas larger houses with evaporative cooling systems designed to chill the air in the whole home are much bigger and have water lines plumbed into them.

Large-scale industrial evaporative coolers used in manufacturing, agriculture, and perishable food storage have large, multi-layered cooling pads that incorporate the latest materials technology to maximize cooling.

A sure sign that your evaporative pads need replacement is the onset of a softening media. Both natural and synthetic fibers are used to absorb water. As the material comes in contact with the various chemicals and minerals in the water, it degrades and starts to soften. 

This is evidenced by the material sagging and stretching.

Despite the claims by manufacturers of high-efficiency cooling materials, all cooling pad materials experience wear and tear due to chemical damage to the synthetic fiber structures as well as physical damage as objects suspended in the air are blown into the material.

The harsher the environment, the more often you will have to replace the cooling media.

Apart from the new cooling media chilling the ambient air more effectively, the evaporative cooler will use less electricity to cool the air.

This brings us to the causes and effects of increased static pressure.

The Consequences of Increased Static Pressure 

Increased static pressure refers to the build-up of resistance to airflow through the cooling media.

For your evaporative air cooler or “swamp cooler” as it is known throughout the southern states, to work properly, it must maintain a constant airflow through the cooling pads.

The large fans in industrial units build up a massive pressure gradient that forces the air through the cooling media. As the air molecules contact the water molecules in the fabric, they transfer heat, causing the water to evaporate and extract heat from the air.

The volume of air passing through the evaporative cooling system is proportional to the quantity of air displaced from the area being cooled. So, any reduction in air-flow volume will reduce the effectiveness of the cooling capabilities of the system.

Dust, sand, pollen, leaves and twigs, and any other airborne debris that enters the evaporative cooler media, clog it and blocks the airflow. This causes an increase in static pressure which not only slows down the airflow and reduces the amount of heat exchanged with the water but has other damaging effects as well.

A regular inspection of the cooling pads goes a long way in increasing the life of the cooling media. Twigs, leaves, plastic, and dust can be removed before it does too much damage and tears can be repaired to prolong the useful life of the material.

There will be increased wear and tear on belts and pulleys, the motor driving the fans, and a consequent increase in electricity consumption to counteract the increased resistance to the flow of air across the cooling pads.

Not only will you pay more for less cooling, but you’ll also accrue increased maintenance costs and a shorter lifespan for all the moving parts within the system.

A cost-benefit analysis will quickly show the prudence of replacing the evaporative media as soon as the static pressure increases above a predetermined level for your system.

So how does the loss of cooling in the evaporative cooling system occur?

Look Out For a Loss of Cooling 

The easiest way to check your system is to monitor the temperature in real-time. Sensors attached to a sender unit that monitors the temperature and produces a useful graph will quickly highlight a worsening efficiency curve.

However, you must bear in mind that even the most efficient evaporative coolers are only able to reduce the ambient temperature by about 15-40°F (0.5-1.25°C).

This cooling capacity is further reduced by an increase in relative humidity. For this reason, evaporative coolers are not recommended for climates that experience high humidity and heat.

But loss of cooling is also experienced with a reduction in wind speed.

Reduction in Wind Speed Also Affects Cooling

The rate at which the air cools is a function of its airspeed across the face of the evaporative media. 

Anything that interferes with the airflow will naturally also reduce the efficiency of the cooling pads. If you have tears or leaks in the evaporative media or the ducting, it will affect the airspeed and therefore the cooling.

To ensure that you maintain the system’s evaporative efficiency, you need to inspect the evaporative media regularly for damage. Most evaporative pads can be repaired if the damage is small. But the longer it is left, the more the material will deteriorate and affect the wind speed through the system.

The Importance of Maintaining Your Evaporative Cooler

To prolong the life of your cooling system, switch it off when it is not needed. This includes the water supply. Drain the pipes and any storage tanks completely, making sure to clean the filters before packing away portable systems. 

You can prevent or slow down the mineral build-up in the evaporative cooler media by testing your water and using treatment tablets where indicated.

For expert advice on installing evaporative coolers in Phoenix, AZ, and the surrounding areas, contact Premier Industries. Their team of professional installers has over 30 years of experience manufacturing and installing evaporative cooling systems for residential and commercial customers. They can also supply you with any replacement parts or accessories you may need.

Categorised in: Evaporative Media

This post was written by Mike Nicolini