How Do Swamp Coolers Work?

Image of swamp cooler on roof

Swamp cooling or evaporative cooling, is a popular, cost effective way to cool your home here in the southwest. Swamp cooling works best in the hot dry climates like New Mexico. Basic swamp cooler function starts with a pan filled with water that will automatically fill as water evaporates. The water is pumped from the pan to a pad which absorbs the water and drains back into the pan. The wet pad filters the air that is drawn from outside by a blower motor and pushed into the house through a duct. As the air moves through the wet pad it cools down and gains humidity (this is where the evaporation happens). All the space in the home will be conditioned by cooler air between supply and return. Supply is the air coming out of the registers (vents) in the house, and the return is an open window or door. The air moving through the house will absorb some of the heat and push some outside. The end result is a cooler and more manageable living condition during a hot dry day.

How To Operate A Swamp Cooler

    1. Locate the swamp cooler control –The swamp cooler control is a panel like any of the types of controllers pictured below. There are also several variations of these as well. It’s also important to note that there are manual controllers and digital thermostat controllers. (See examples below).
  1. Turn the pump on – The first step is to turn the pump on to wet the pads before turning on the fan. If you have a manual control always turn the pump on for approximately 5 minutes to ensure the pads get wet enough. Then you also turn on the fan to either high or low to begin circulating cool air through your home. If you have a digital thermostat control you can set the pump and fan to turn on automatically by setting a temperature threshold that will turn on the cooler when your home reaches a certain temperature.
  2. Always open a window(s) – when running your swamp cooler. As swamp coolers push cool air through the duct system in your home that hot air gets pushed out through open windows. This is opposite of refrigerated air conditioning where you keep your windows and doors shut when the air conditioner is on.

How to get the most out of your swamp cooler

Here are some quick tips along with a video that shows you what you can do to ensure that you get the coolest temperatures from your swamp cooler. If you don’t feel comfortable doing any of these or getting up on your roof, please contact a professional to evaluate your swamp cooler.

  • Make sure your pads are wet – if you feel that your swamp cooler isn’t cooling your home, the first step it to check if your pads are getting wet. If the pads aren’t wet your swamp cooler will just blow hot air from outside into your home. If your pads aren’t getting wet you may have an issue. You could have problems with your pump or clogged water lines.
  • Do you have enough relief air? – Check to ensure you have enough windows open in your home to push the hot air out. Also, make sure you open windows in the hottest part of the house to bring cooler air into those rooms.
  • Get a digital thermostat – a digital thermostat will allow you to set a temperature for your swamp cooler to automatically turn on and off to gain better control of the temperature in your home.
  • Humidity – A swamp cooler’s cooling effectiveness relies on humidity levels outside. If the humidity levels rise too high your cooler will have a harder time lowering your home’s indoor temperature. See the video below to learn more about humidity levels and efficiency temperatures.

If you continue to have problems after performing these tips, it may be time to call a professional to repair your swamp cooler.