Humidity is defined as the amount of moisture in the air. When the air is dry, the humidity is low. This is a common condition in heated winter homes. This causes respiratory problems such as the common cold, sinus, asthma and allergies. Other symptoms include itchy eyes, itchy skin, dry nose, sore throat, chapped lips and an unquenchable thirst.

A humidifier is essential for stopping these conditions from happening. These days you won't find too many homes without humidifiers.

When choosing a humidifier, the most important component is the filter. There are basically two types of humidifiers on the market - filtered and filterless humidifiers.

The main purpose of the filter in the filtered kind of humidifiers is to clean the air by trapping the sediments and the dirt particles.

The first and the biggest disadvantage is that the filters must be changed.

The second disadvantage is the hygiene. You'll find that although this kind of humidifier doesn't need to be cleaned on a daily basis, its filter can get very dirty over time. Unchanged filters can breed disease and illness.

Thirdly, you have to pay out money each month when you buy replacement filters. Buying new filters each month can add up to the cost and at this rate, they can double the cost in one year.

Filterless humidifiers are as effective as any filtered humidifier except that they don't use a filter. They use a grid which has an electrostatic charge to stop the dust particles.

One big benefit of using a filterless humidifier is the fact that it does not force you to spend money on filter changes each month. It is also worth noting that this type of humidifier is not nearly as loud.

Most people would agree that the biggest drawback to using a filterless humidifier is that it has to be cleaned on a weekly or even daily basis, depending on use of course. These humidifiers get dirty quickly and if not cleaned, they will become hazardous to your health. You may also find that the filterless humidifier is a little pricier than its filtered cousin.

A filterless humidifier is not suitable for the lazy and busy as cleaning this humidifier can be a chore. In this case you would want to buy a humidifier with a humidifier. Just keep in mind that you will pay more each year to run this.