Quick Answer
Using evaporative coolers off-grid is a practical and cost-effective option, especially in dry climates, but it requires careful planning to ensure sufficient water supply, power, and cooling performance.
Power Requirements for Evaporative Coolers
Evaporative coolers, also known as swamp coolers, are a popular off-grid cooling solution due to their low power requirements. A typical evaporative cooler consumes 1-2 kilowatts of power, which is significantly less than a traditional air conditioner. To size a solar array for an evaporative cooler, consider the following: assume a 2-kilowatt array, with an average daily solar irradiance of 5 peak sun hours (PSH) in your location. This will provide around 10 kilowatt-hours (kWh) of energy per day, which should be sufficient to power the evaporative cooler.
Water Supply Considerations
Another crucial aspect of evaporative coolers is water supply. The unit requires a steady flow of water to function effectively, and in off-grid applications, water can be a precious resource. To ensure a reliable water supply, consider installing a rainwater harvesting system or a well pump with a storage tank. A general rule of thumb is to store at least 1,000 gallons of water per person per year, but for an evaporative cooler, you’ll need to consider the unit’s water consumption rate, which can range from 1-5 gallons per hour.
DC Unit Options and Sizing
DC evaporative coolers are becoming increasingly popular in off-grid applications due to their efficiency and reliability. When selecting a DC unit, consider factors such as airflow, water consumption, and power requirements. A good rule of thumb is to choose a unit with a 1-2 ton cooling capacity, which will require a 2-4 kW solar array. Additionally, ensure that the unit is designed for DC operation and can handle the voltage and current requirements of your solar array.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.