Swamp coolers are economical alternatives to central AC when you live in drier, low-humidity areas.
While they have fallen out of favor among many homeowners in recent years, swamp coolers (also known as evaporative coolers) can still be an efficient and cost-effective way to cool your home, providing the conditions are right. Swamp coolers, used properly and in the right circumstances, are a classic example of how some old school technology can still deliver modern results.
About swamp coolers
Unless you happen to be an HVAC geek, your exposure to a swamp cooler may be limited to either seeing or living with an old-fashioned, window-mount air conditioning unit. These are compact versions of how (on a larger scale) evaporative coolers can work to reduce the temperature in a space. (As far as that goes, you could also say that the very old-school method of placing a fan in front of a block of ice, pointing the fan into an area you want cooled, is the precursor to the swamp cooler.)
Swamp coolers use the process of evaporation (thus the other term, evaporative cooler) as a central technique for cooling air and distributing that air to the desired space. The basic residential use swamp cooler consists of a square box with absorbent pads on all sides. There is a water pump that pumps the cold water from the tray in the bottom through the pads. A fan inside the unit draws outside air across the soaked pads, cooling it, then sending it into your house.
In order for these units to work efficiently, there has to be some place for the warm air coming in from outside and off of the soaked pads to go, as well as the warmer house air that is being displaced by the cooled air. Most swamp cooler users keep one or more windows in the house open to accommodate this procedure..
Understanding humidity levels
An evaporative cooler works best if you live in an area with low relative humidity. Just as with swamp coolers, measuring and reporting on relative humidity is becoming rare in many areas. If you’re a fan of weather reports, you may be familiar with the term dew point. This is a measure of relative humidity and can be helpful in determining if a swamp cooler would be a wise cooling choice for your home. The dew point is the temperature at which the water vapor in the air (at a constant barometric pressure) condenses into liquid water at the same rate at which it evaporates. To simplify, the higher the dew point, the higher the relative humidity.
When the air (outside or inside) has a large amount of moisture in it, the humidity levels are high. Dew points measuring 55° F and lower typically present excellent conditions for a swamp cooler to reach maximum efficiency. One reason is that swamp coolers do not remove humidity from the air like some air conditioners do. In fact most swamp coolers don't work well at all in high humidity areas as the moist, warmer outside air will quickly overpower the cooler water in the unit.
If you notice that the air temperatures where you live rise while the humidity levels remain low or even relatively constant, a swamp cooler might help. When used properly, the cooler can drop the temperature in your home by 30 degrees or more quite quickly and generally with far less energy use than that needed to cool air using a refrigerant or similar system. While swamp coolers are still commonly used in commercial settings, residential use is becoming more concentrated in areas that experiences what we all know as that dry heat.
For families that still rely on a swamp cooler for air conditioning a home, innovations do continue to come along to improve these units. For example, many newer swamp coolers feature additional pads in each unit designed to pull and filter out allergens and dust from your home. Many newer units have improved the water re-circulating features and have added filters and other means by which the water used does not quickly become fetid standing pools attracting mosquitoes. By and large, swamp coolers use far less energy than central AC units and as small motors turning fans improve in efficiency, the energy efficiency advantage grows.
Residential evaporative coolers don't rely on an integrated HVAC system. In fact, there are still a number of window-mount and portable swap cooler models that require little more than adding cold water and routinely maintaining the filters and pads. If you are considering an evaporative cooler requiring more installation details, it would be a good idea to solicit installation estimates from different contractors to get the most accurate pricing for your area. You might also find that local contractors have access to some discounted, wholesale or builder prices for a unit you may have in mind.
It’s hard to get an accurate listing of swamp cooler prices as they can vary from region to region and even from store to store. We’ve found online prices for standard units ranging from around $500 for a smaller unit to well over $2,000 for a larger unit. (Many of the portable units are priced even lower.)
Before purchasing any cooler, check out the warranty and make sure that it covers normal wear and tear, coverage of what few moving parts there might be, and any damage or manufacturer-related defaults to the unit.
Find a trustworthy contractor in as little as a few minutes. Reply! can be a great resource for you to find a swamp cooler that can significantly drop the temperature in your home, without an upward movement of your energy use and utility bill needle. Use your evaporative cooler to enjoy cool air all summer long.