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Water is critical for the functioning of evaporative coolers. You can think of water usage for evaporative cooling in the same context as electricity for refrigeration. Your water consumption rate may be of some concern to you, so you may wonder how much water an evaporative cooler uses.
We will discuss evaporative coolers and how they function. Then, this post looks at the types of evaporative coolers and how long their water supply lasts. You can also learn about factors affecting water usage in evaporative coolers and tips to improve the efficiency of evaporative air conditioners.
What are Evaporative Coolers?
Evaporative coolers reduce air temperature and turn water into cool vapour. They are an improvement on the age-old method of fanning jars as water coolers to keep rooms cool.
How evaporative coolers work
Evaporative coolers provide a cooling effect after they consume water via evaporation. First, they extract hot air from the outside through a series of wet filter pads. These pads get water from the tank at the unit's base. As water from the filter pads evaporates, it draws heat from the air and humidifies it. After that, the cooled, moist air is spread through the home.
Thus, you can consider evaporative coolers to function by cooling your home's air and creating a cooling breeze. Ultimately, evaporative coolers continue to supply fresh, cool air through your home since they are an open system.
On the negative side, evaporative coolers can bring in external pollutants like dust, pollen, and smoke. In addition, ducted evaporative systems need extra maintenance for winter so that hot air does not rise through ceiling vents and ducts and leave through the cooling unit on roofs.
Meanwhile, the relative humidity of the outside air has a limiting effect on the cooling capabilities of evaporative coolers. The water evaporates less easily from the pads. Thus, evaporative coolers tend to be more effective in drier climates.
Types of Evaporative Coolers
Read on for a highlight on the types of evaporative coolers:
Ducted evaporative coolers
Ducted evaporative coolers have a cooling unit on the roof. The fans in ducted evaporative coolers draw in warm air from the outside through the filter pads in the head unit. This warm air evaporates the water to create cooled and humidified air.
They also have ductwork that supplies your home with the cooled air and ultimately moves the air to outlets in the ceiling. These evaporative coolers come in standard and inverter models. The inverter models are known to have lower running costs due to their variable-speed motors.
Portable evaporative coolers
You can use portable evaporative coolers to provide spot cooling and to cool small rooms. While these evaporative cooling systems tend to be cheap, they are more costly and have limited cooling potential.
Renewable Water Resource for Evaporation Cooling
Some people think the water usage in evaporative coolers amounts to water wastage, but this is far from the truth. Water is 100% renewable after it is evaporated in evaporative coolers.
You can put the water that is systematically purged from the cooler's reservoir to other uses such as garden or tree watering. Moreover, evaporated water returns to nature very quickly and cleanly.
Note that you need to refresh the water supply of ducted evaporative coolers so they do not get too salty. Different brands or models use their range of water management systems.
How long will the reservoir's water supply last?
If you do not have a direct water source, the water in a filled tank will evaporate within 2 to 10 hours of use. However, this depends on the evaporative cooler's water capacity, temperature, humidity, and ambient conditions.
How Much Water Do Evaporative Coolers Use?
It is unsurprising for evaporative cooling systems in houses to consume several hundred litres of water daily. Typical water consumption rates can range from 41L to 115L per hour.
The amount of water available for evaporation can determine how effective your evaporative cooler is. This is why evaporative coolers are not ideal in areas with water scarcity.
Factors affecting water usage in evaporative coolers
The amount of water used in evaporative coolers depends on the unit's size. Other important factors affecting water usage include the unit's fan speed and the day's humidity. The water evaporation rate also depends on the speed with which air passes through the media, the media's efficiency, and the depression of the actual wet bulb.
When buying ducted evaporative coolers, determine what water management system is used and your area's standard hourly water consumption. As recommended by manufacturers, you may connect your evaporative cooler to a regular garden hose. This way, the factory-installed internal float can help to self-regulate the water level.
Running costs of evaporative coolers
You should pay attention to the stated cooling capacity and the fan speed of evaporative coolers. These factors directly affect the actual running costs of evaporative coolers. It isn't easy to compare models of evaporative coolers because they do not have efficiency labelling requirements.
You should get a refrigerative cooling system if you use solar in your home. This is because the water costs – say from water corporations – associated with evaporative cooling are likely to outweigh energy costs.
Choosing the Right Size of Evaporative Coolers
Local installers consider airflow and the volume of your space that needs cooling before providing an accurate evaporative sizing quote. They will also factor in local humidity levels.
Evaporative coolers vs. air conditioners
You may know about evaporative coolers and air conditioners and their cooling effects. However, you may wonder which option cools the air better. Evaporative coolers consume less power since only the fan and water pump need energy. However, this depends on the features and capacity.
As a result, the ability of evaporative coolers to use electrical power to provide cool air is limited. On the other hand, air conditioners have a much more powerful ability to convert energy into coolness.
Effectiveness of different types of air conditioners
- Split-system air conditioners can cool one or several rooms.
- Portable air conditioners can cool rooms that lack built-in air conditioner units but are less efficient than split systems.
- Wall/window air conditioners are more reasonably priced than split systems and are usually installed in windows or external walls.
- Reverse-cycle air conditioners provide both heating and cooling effects all year round. As such, they do more than a unit that only cools air.
- Ducted air conditioning systems are suitable if you want to cool your entire home, but they can be expensive.
The water consumption rate of evaporative air coolers
Evaporative air conditioners have water-soaked pads that filter warm air and produce evaporation that cools the air. This evaporation cooling process needs a steady water flow. The water consumption rate in terms of litres of water per hour depends on heat and humidity levels.
However, larger units use as much as 75.7 litres per hour. Some evaporative air conditioners use between 10 to 30 litres of water per hour. During hot weather, you may find that up to 100 litres of water can evaporate every hour. This amount can add up to 30,000L of yearly water use.
Tips for Improving Evaporative Cooler Efficiency
- The differential between your air conditioner's outside temperature and the thermostat setting should not exceed 8°C.
- You can use the thermostat's Economy mode or Eco mode to help reduce power consumption.
- If you leave them on default settings, evaporative air conditioners may use a lot of water.
- You can maximise the water efficiency of evaporative air conditioners if you adjust them on humid days.
- Replace wood fibre cooling pads of aircon annually to maintain efficiency. Cellulose-bonded paper pads tend to last longer.
- You may opt for those evaporative air coolers with variable speed fans as they are more energy and water-saving.
- You may choose portable swamp coolers since they can use up to 75% less electricity than portable air conditioners.
Saving water consumption of evaporative air conditioners
- One way of saving water in your evaporative air conditioning system when cooling your home is to clean and maintain it regularly.
- You can switch evaporative air conditioners to 'fan only' settings on humid days.
- Your windows and doors should be open for air to flow outside. Insufficient air flow can add pressure to the fan.
- One way of managing water usage in swamp coolers is to adjust their water drains.
- Consider the size of your swamp cooler water supply tank when getting hose connections.
Hire Professionals for Evaporative Cooler Services
With this guide on how much water evaporative coolers use, you can better manage your evaporative cooling system. However, sometimes, you need to call in expert help. For instance, a professional air conditioning contractor can help service components such as filter pads. You can also call on them for air conditioner installation and repair services.