What is an Evaporative Cooler?
Evaporative coolers, also known as swamp coolers, are an effective and energy-efficient cooling solution, particularly in dry climates where relative humidity is consistently below 50%. These systems leverage the natural process of water evaporation to lower air temperatures, making them ideal for greenhouse environments in arid regions.
The basic principle is simple: as warm, dry air is drawn into the cooler, it passes through water-saturated pads. The water evaporates into the air, reducing the air temperature by approximately 10°F to 20°F before the cooled air is pushed into the greenhouse. This cooling effect not only helps maintain optimal growing temperatures but also adds moisture to the air, which can be beneficial in extremely dry environments.
How to Find the Right Cooler for You
To ensure your evaporative cooler is effective, it’s important to match the system’s capacity to the size of your greenhouse. This is done by calculating the volume of the greenhouse, which is determined by the formula:
Volume = Length × Width × Height
The result, expressed in cubic feet, represents the amount of air that needs to be circulated and cooled. Once you have the volume, this number also corresponds to the recommended CFM rating (Cubic Feet per Minute) of your evaporative cooler. The CFM rating indicates how much air the cooler can move per minute.
For example, if your greenhouse is 30 feet long, 20 feet wide, and 10 feet tall:
30 × 20 × 10 = 6,000 cubic feet
You’ll want to select an evaporative cooler with a minimum CFM rating of 6,000.
To ensure optimal performance, it’s often advisable to choose a cooler with a slightly higher CFM rating than the minimum. This provides a buffer for heat spikes, improves air circulation, and accommodates any additional cooling needs that arise from solar gain, equipment heat, or high plant density.
In addition to proper sizing, regular maintenance—such as cleaning the pads, checking the water supply, and inspecting the fan—is essential for long-term performance and energy efficiency of your Evaporative Cooler.
