Humidity and Moisture Levels In The Home

Clueless about humidity levels in the home? If you’re reading this article, then you no doubt have some questions regarding humidity levels such as what is a suitable humidity for home? What is Relative Humidity (RH)? Or just how can dehumidifiers for home use help with dealing with your humidity levels? Below, everything you need to know is broken down.

Whats the Difference?

Moisture or “Water Vapour”

To put it simply, moisture (or water vapour) is water in a gas form (liquid being the obvious water, and solid being ice). One main way that water vapour increases is evaporation. Water evaporates everywhere; rivers, plants, the sea, lakes, puddles, the ground and just about any water source. The amount of moisture in the air can vary from a little to a lot, and most of the moisture contained within our atmosphere is in the initial ten thousand feet about the surface. Humidity is basically a measurement of the moisture/water vapour in the air.

Absolute humidity

Absolute Humidity is a measurement of the amount of moisture in the air, regardless of air temperature. And is measured in grams of water vapour per cubic meter volume of air. The more moisture/water vapour in the air, the higher the absolute humidity.

An example would be that at max, about 30 grams of moisture can exist in a cubic meter volume of air a temperature around the mid 80’s.

Relative Humidity

Relative humidity also measures the amount of moisture in the air, but as a percentage relative to air temperature. Basically, it’s a measurement of the ACTUAL amount of moisture/water vapour currently in the air compared with the water vapour amount that can exist at the current temperature. It is simply a measurement as a percentage, telling you just how much of the air around you is water vapour, while being relative to the temperature. So 70% RH = 70% water vapour, 30% air.

Whats A Suitable Humidity Level for Home?

Different relative humidity levels can suit different situations. The typical (and comfortable) humidity level suitable for home is around 50-55%. Mold will struggle to form and expand in anything under 50%, and it will be comfortable to live and breathe in.

There are situations where lowering the humidity will benefit though, such as Asthma sufferers. Dust mites and the debris that they leave behind are a common aggravator of those suffering from Asthma and they enjoy levels of 50% or higher. So lowering the level to around 40% will help control the mites and reduce the effects.

Another example is the condensation on windows that can occur in the winter months (or cold in general). A humidity of around 30% would help prevent this, all though some may find the air a little dry at this level.

So, heres a simple recap:

General “Right” Level: 50-55%

Dust Mite Prevention: 40%

For Asthma Sufferer’s: 40%

Condensation in the Cold: 30%

How Would I Assess My Humidity Problem?

The easiest way to do this would be to use a humidity meter or otherwise known as a Hygrometer. If you dont own or want to have to purchase a Hygrometer then the other way is to simply keep an eye out for symptoms of excess moisture such as dampness, rot and mould.

How Can A Dehumidifier Help Me?

Many dehumidifiers for home feature humidistats and auto shut off features when they reach your required humidity. You could for example, have a basement that is at 70%, and you wish for it to go down to 40-50% and keep it at that, so you would programme your dehumidifier for home to shut off once it reaches 40%, but maintain it at that and automatically bring it back down when needs be.

Or for the more simple and cheaper models which dont feature humidistats, you could assess your RH with a hygrometer (humidity meter) and just keep tabs on what level it is decreasing too.