Are you looking for a low-cost, environmentally friendly alternative to air conditioning? Ventless evaporative coolers are the solution to hot summer misery but only as long as you live in an area that has fairly low humidity when it gets hot.

You have probably already heard of swamp coolers, which is another name for these eco-friendly cooling machines and how they work great in really dry climates like you get in the mid west states or desert areas.

But a lot of people living in more humid areas are buying them and being disappointed when they don't produce the same kind of cold air they expect to get from air conditioners. Let's look at why this is and what can be done about it.

Why Humidity is Bad for Swamp Coolers

The way these coolers work is to fan room temperature air through a wet membrane and evaporate that moisture, combining it with the air that is forced out the front of the unit. When warm air is mixed with tiny droplets of moisture in that way, the moisture absorbs some of the heat, reducing the temperature of the air.

When that moisture-rich air is pumped into the room being cooled, the humidity of the atmosphere in that room is raised continually, until a point is reached where the air is completely saturated. As that happens, the air becomes less and less able to absorb more moisture.

As less moisture is absorbed into the air, less heat is also absorbed and so the coldness of the air being emitted from the swamp cooler is reduced in proportion to the humidity level of the air.

At the point of saturation, no more moisture can be added to the air and so no more heat can be absorbed by the process, so the air fanned out the unit now stops feeling cold.

When the starting humidity is already high, as in areas near large bodies of water (lakes, large rivers or the ocean), there is already little room for adding any more moisture into the air, so an evaporative cooler doesn't have the latitude to produce its most effective output. In other words, it just can't create enough air coldness.

People living in these areas that buy swamp coolers are already doomed to disappointment because the units simply cannot create an air chilling effect. And so buyers send the units back to the manufacturers complaining their product doesn't work!

Living in Dry Climates

On the flip side, if you live in an area with low humidity, there is a huge volume of dry air just waiting to absorb the moisture from one of these devices. The only way they are going to see the effectiveness reduce is by running a swamp cooler in an enclosed space with no ventilation (to the outside).

What happens then is the same as above. As the unit pumps more and more damp air into the atmosphere, the room's humidity rises until it reaches saturation point.

Of course, this is easily remedied. Simply by opening a window and a door a crack and allowing a cross-flow of outside air to circulate through the room will help maintain the dry air in the room and the cooler will keep working just fine.

The unfortunate fact of this story is that those living in dry climates can take full advantage of the low energy consumption and eco-friendliness of evaporative cooling devices, while those living in humid areas cannot. It's like a zip code lottery whether you get to save money or spend more on rising electricity costs because you need air conditioning to keep you cool.

And there is no other alternative that is quite as effective or convenient.

If you want to read more about how evaporative coolers work and where they are best deployed, visit this website (Ventless Portable Air Conditioner):

That site is full of great information! Likewise, there is a helpful government Dept of Energy site that explains the energy saving potential for these coolers here: