Optimum Indoor Relative Humidity Levels - Do You Need a Humidifier?
It's easy to look at the symptoms caused by dry air, and decide that you need a humidifier. To be honest, this is usually the correct answer as most buildings benefit from at least a little humidification during cold weather. But, as this can be quite a large investment, it's better to be sure.
What you need is a humidity meter, also known as a hygrometer. They are easy to find and cheap to buy, so there is no reason not to get one. You can then measure the humidity in all the rooms where you spend most time. You will soon discover that humidity levels vary during the day. This is perfectly normal, so it is important to take readings in the morning, during the day, in the evening and even at night in the bedroom.
The optimum relative humidity level is generally considered to be between 40% and 50%. Anywhere between 30% and 60% is acceptable, and but a figure below 50% is recommended to help control dust mites which are bad for allergy sufferers.
