types of evaporative coolers

Besides traditional and cheap swamp coolers, there are now also portable evaporative coolers (for space cooling in moderate climates) and efficient two-stage units, and also multi-speed coolers to better respond to specific weather conditions.

Direct evaporative coolers

In direct evaporative coolers the air passes and is cooled directly through water-soaked pads. That’s the traditional technology, and the cheaper, simpler and most efficient for typical dry climates.

Two-stage evaporative swamp coolers

Two-stage evaporative coolers involve... two stages: in the first stage, warm air is cooled inside a heat exchanger (instead of directly cooled through water-soaked pads, as in direct swamp coolers).

In the second stage the pre-cooled air is driven through the water-soaked pads, but since it has been previously cooled, it picks up less humidity. The advantage of this new technology is exactly that: a lower relative humidity (around 50-70%, compared to the typical RH of 80% of traditional direct evaporative coolers).

That’s an important advantage in wetter days and semi-dry climates.

Portable and Window evaporative coolers

The market is now offering window and portable evaporative coolers, some of them on wheels. These small coolers incorporate direct evaporative technology. Their specificity is not only in their size, and mainly in their scope: space cooling, instead of whole-house cooling.

Portable and windows swam coolers goal is to cool just a room or small part of a house, and they are a good option in moderate climates, in hot weather conditions. They can reduce the room’s temperature by 5°–15°F (3-7ºC).

In other climates these units aren’t usually sufficiently efficient.

Two-speed coolers

The market is offering now, two-speed coolers, able to provide varying cooling loads. In dry climates with significant disparities in temperatures, these coolers are undoubtedly advantageous.

Units with Bleed-off valves

Many modern evaporative coolers incorporate a bleed-off valve system, which purges water about every six hours. In regions where water easily causes sediments and mineral build-up, bleed-off valve systems are highly recommended.

Filters

Many evaporative coolers do not have air filters, but they can be fitted to the cooler during installation.

Filters remove incoming air dust, which is important to avoid allergies on people prone to them.