Very high relative humidity is potentially more harmful to collections than a period of moderately warm temperatures. Extended periods of humidity at 65% and above can lead to mold growth in vulnerable collections.
The Health and Safety Executive recommends that relative humidity indoors should be maintained at 40-70%, while other experts recommend that the range should be 30-60%. Most people find 30-60% most comfortable and this is the level that Airthings recommends.
Sometimes, humidity or dampness (water vapor) in the air can supply enough moisture for mold growth. Indoor relative humidity (RH) should be kept below 60 percent -- ideally between 30 percent and 50 percent, if possible.
Water Vapor
If there are no cold-condensing surfaces and the relative humidity (RH) is maintained below 60 percent indoors, there will not be enough water in those materials for mold to grow. However, if the RH stays above 70 percent indoors for extended periods of time, mold will almost certainly grow.
Many rooms within a home or office building do not get colder than 50 to 65 degrees Fahrenheit, even in winter, and mold can grow in those temperatures. The idea that cold weather will kill all kinds of mold colonies is a myth.
Generally, your home should fall between 40% and 60%. This will ensure that the air in your home is not too dry and not too humid. This range is beneficial for human health, comfort and the integrity of your home.
The temperature in your home
Keep doors of unheated rooms open to allow some heat into them. Ideally your home should be heated between 18 to 21 degrees Celsius, but older people, babies and people who are less mobile may need it to be warmer.
If the humidity in a room increases, mold will start growing in patches on walls, clothes, and more. So, to answer your question, dehumidifiers do NOT kill mold, but they do prevent it by reducing humidity. If you have a mold problem in your home, don't wait. Mold spreads as long as it has a water source.
Most yeasts and molds are heat-sensitive and destroyed by heat treatments at temperatures of 140-160°F (60-71°C).
Mold will grow in your home with humidity levels over 55% or higher. It can be controlled with a dehumidifier and good ventilation. Dry walls with a moisture level of over 17% may often need to be removed and replaced by a drywall service.
Molds require oxygen, but not light, for growth. Mold growth can continue indefinitely without light.
Mold spores won't die even without moisture. The only way they do is when you completely get rid of them. Does inactive mold need to be removed? Yes, you need to clean surfaces with inactive mold because they can be reactivated by moisture.
Dehumidifiers should be used in areas of persistent high (i.e., greater than 60%) relative humidity when other means, such as improved ventilation and remediate of water intrusion, are not feasible or sufficient to reduce levels to acceptable values.
less than or equal to 55: dry and comfortable. between 55 and 65: becoming "sticky" with muggy evenings. greater than or equal to 65: lots of moisture in the air, becoming oppressive.
Ultimately, high humidity levels have many different causes: climate, daily activities, HVAC issues, and poor ventilation are just a few of the culprits. Depending on the cause, solutions can range in cost from the price of one of the best dehumidifiers to the cost of HVAC service or AC repair cost.
Hydrogen peroxide, commonly used to disinfect wounds, is active against a wide variety of micro-organisms including mold. It acts by releasing oxygen at a rapid rate, which kills mold by oxidizing the surface and breaking down proteins and DNA.
Mold hates light. Other than moisture there's nothing mold loves more than dark places. An easy prevention against mold growth is opening your blinds and shades. If it's warm enough out, open the windows.
Condensation, damp and mould
Colder homes often have more problems with damp and mould. Damp can also cause deterioration of the building, making it harder and more expensive to repair.
DampRid's Odor Eliminator products don't just mask odors, they eliminate them by breaking up their molecular structure. And DampRid can help protect your home against moisture damage, solving many mold, mildew and odor problems.
Leaving your dehumidifier on all the time can result in dehumidifying too much, leading to a dry indoor environment. It can cause dry air, leading to respiratory issues, dehydrated skin, and static electricity.
High humidity levels create damp environments conducive to mold spore blooms. On the other hand, low humidity inhibits mold growth. According to the Environmental Protection Agency (EPA), indoor humidity levels should be maintained between 30% and 50% to prevent mold colonization.
Mould thrives in damp areas such as windows, where there is dust, dirt or organic material, that's why the number one way to reduce mould is to open your windows regularly. By opening the windows at least once a day, this allows the mould spores to escape and lets patches of moisture dry out.
The only effective way to permanently get rid of mould problems is by reducing the build-up of moisture in your home. This can only be achieved through better ventilation.