Are evaporative cooling units right for your home?

While winter might not be the natural time to consider your air conditioning options, the off-season is the most budget-friendly time.

For many, air conditioning means either a window unit or a traditional central-air system. Some experts, however, say a more effective means of chilling out on a hot day spent outside is a portable evaporative cooling unit - a small electrical device on wheels that can provide cool, blown air on demand.

Unlike a mobile air conditioning device, which uses a condenser coil to cool the air and an exhaust hose to remove hot air, a portable evaporative cooler pulls exterior hot air into water-soaked pads or other cooling medium; this air is cooled via evaporation and then blown out, resulting in comfortable air - like a cool breeze flowing across a lake might feel.

This technology is more efficient and affordable to operate than traditional air conditioning, using only about as much electricity as a hair dryer or toaster. Evaporative units also run on fewer parts, don't need a refrigerant and don't require hose venting.

"These portable coolers are ideal for families who are seeking ways to extend the enjoyment of the outdoors, whether lounging, grilling or playing," says Giacomo Calzavara, managing director of Jmatek North America in Mahwah, New Jersey. It manufactures Honeywell evaporative cooling devices. Calzavara notes that portable units usually start at $100 and up.

"These coolers can keep guests comfortable, even on the hottest days, and can cool surrounding temperatures by up to 15 degrees. And they're versatile with heavy-duty wheels, making them easy to move wherever the action is for on-the-spot cooling."

Gary Layman, a homeowner in Cleveland, Oklahoma, purchased a portable Portacool brand model for his backyard deck and has no regrets.

"In our oppressive Oklahoma heat, it's been more than worth it, as we can now better enjoy our time outside," Layman says. "It's so much better than using fans alone. I can also roll it easily to my workshop area in the garage."

Evaporative coolers - also called "swamp" coolers - are best used in areas with a dry, low-humidity climate, says Jason Roberts, senior marketing specialist at My Handyman Services in London.

"Their advantages are that they have low operating costs and only two major mechanical parts: a fan motor and water pump. However, performance is affected when humidity levels are high, which can decrease the cooling capacity of these devices," Roberts says. "Additionally, a frequent supply of water is needed to wet the system's pads, and corrosion can form on the unit's materials due to high dew point conditions."

Before purchasing a portable evaporative cooler, prepare to do your homework.

"Research available models and sizes," Calzavara says. "Look at the space you want cooled, whether you'll have full sun or shade, and consider whether you're in an arid or humid climate. All these factors contribute to which model best suits your lifestyle so that you can get the best performance possible out of your unit."