What Difference Does a Humidifier Make? 

Humidity also plays a role in IAQ. There is a significant increase in respiratory infections during dry winter months. Too much humidity increases the presence of fungi and dust mites, and can influence the emission rate of some chemical pollutants, for example, formaldehyde. Too much or too little humidity can increase the presence of bacteria and viruses, and aggravate allergic rhinitis and asthma conditions. 

Controlling relative humidity inside a home has numerous IAQ advantages. The optimum range of relative humidity inside a home should be between 40% to 60%. Within this range bacteria and fungi are eliminated and viruses, dust mites, respiratory infections, allergic reactions, and asthma are significantly reduced. 

An added benefit to controlling humidity within the optimum range is that you will feel more comfortable. It is generally agreed among homeowners, that during extreme cold, dry weather they feel uncomfortably cold even with the thermostat set at 72 degrees or more. By increasing indoor relative humidity levels with a humidifier to about 43%, homeowners find they “feel” warmer and can often turn their thermostat down one or two degrees. 

What Should I Set my Humidifier’s Humidistat Setting to?

Humidistats should be set according to the manufacturer’s recommendations. Typical manufacturers recommendations: 

35% when outdoor temperatures are above 20 °
30% when outdoor temperatures are 10 °to 20 °
25% when outdoor temperatures are 0 °to 10 °
20% when outdoor temperatures are –10 °to 0 

Humidifiers should be shut down during summer when your cooling system is on. The condenser on your air conditioning unit is usually sufficient for removing excessive humidity and keeping you comfortable.