Humidity levels tend to be higher at the floor than at the ceiling, though warmer air rises. Due to gravity, moisture is heavier than air and tends to settle down toward the ground. Also, cooler air tends to sink toward the floor, which can cause condensation to form and increase relative humidity.
It's normal for a home's upper floors to have a humidity range of 1% to 5% higher than the bottom floors. Once this humidity range exceeds 5%, you might be experiencing indoor humidity problems.
Basements are often more humid than other rooms because moisture from the ground can seep through basement walls. If the humidity is over 50 percent or under 30 percent in one or more zones of your home, the following solutions will help you get your humidity levels in check.
It is actually quite normal for the second floor of a home to be more humid than the first. If the indoor air becomes warm, it has a higher level of moisture. This means it has a higher level of humidity. The humid air is actually less dense than that of dryer air.
Moist air is lighter and less dense than dry air with the same temperature and pressure. The air that has accumulated moisture becomes lighter and rises to the top.
On average, moisture availability (both relative humidity and absolute vapor pressure) decreases with elevation, but the seasonal and diurnal variability in relative humidity (RH) is enhanced toward the mountain summit.
Warm air can possess more water vapor (moisture) than cold air, so with the same amount of absolute/specific humidity, air will have a HIGHER relative humidity if the air is cooler, and a LOWER relative humidity if the air is warmer.
We do not recommend placing a dehumidifier directly against a wall or piece of furniture. Instead, put it at least six inches away from these vent-blocking surfaces. For dehumidifiers that cover large areas, it's a good idea to place them somewhere central such as a hallway or landing.
Best Humidity for Sleeping
The best relative humidity for sleeping and other indoor activities has been debated. According to the Environmental Protection Agency, the best indoor relative humidity falls between 30% and 50%, and it should never exceed 60%. Other studies suggest 40% to 60% is a better range.
High humidity in a house can be caused by many things, but the biggest reason is poor ventilation—in other words, air isn't being circulated properly, which causes the air in your house to become stagnant and humid. The other major reason? Too much air exchange with the outside.
Water can enter your home by leaking or by seeping through basement floors. Showers or even cooking can add moisture to the air in your home. The amount of moisture that the air in your home can hold depends on the temperature of the air. As the temperature goes down, the air is able to hold less moisture.
Our body produces sweat to help keep us cool, but that only works if the sweat evaporates, because evaporation is a cooling process. So when the relative humidity of the air is high, meaning the air has a high moisture content, the sweat evaporation process slows down. The result? It feels hotter to you.
Signs of high humidity in your home include: Condensation on windows during the winter. Excessive mildew in the bathroom. Mold growing on interior surfaces (corner of a closet, kitchen or bathroom).
Low humidity works better with the body as it allows moisture to evaporate more efficiently, which in turn cools the body. On the other hand, high humidity limits the body's ability to cool off as sweat is harder to evaporate. This makes us more uncomfortable.
Assuming both rooms have same temperature to start with, yes, moisture moves from the 80% to the 10%. Yes, it transfers from from high humidity to low humidity the same way heat transfers from higher to lower temperature. How much? It is decided by the mass transfer property of the material across the rooms.
How Air Conditioning Lowers Humidity. Contrary to what you might think, your air conditioner doesn't increase cool, dry air in your home—it eliminates heat and humidity. The process involves refrigerant, which soaks up heat and moisture effectively from the indoor air.
Ideal in-home humidity levels should hover around 45%.
Anything under 30% is too dry, and over 50% is too high.
According to Energy Star, the ideal indoor relative humidity should be between 30 and 50 percent—anything higher than 50 percent is considered high. High humidity levels can cause discomfort and health issues, and excessive humidity can even cause damage in a home.
Dehumidifiers can't attract the moist air with the doors closed! Opening your doors slightly allows sufficient airflow so your dehumidifier can do its job. Easterly-facing walls get less sunlight, so they suffer most from condensation.
Although the energy consumption for small and medium-sized dehumidifiers is relatively low, long-term usage (especially older, less energy-efficient models) can add up to be quite a substantial amount. This is compounded by the fact that most dehumidifiers run 12 to 24 hours daily.
No, your dehumidifier should not have to run constantly to regulate the air humidity. An optimal humidity level to shoot for is between 30 and 50 percent.
So, in a home, humid air rises upwards, not downwards. Problem 2: If humid air WAS denser than dry air, basement vents still wouldn't work. Let's pretend for a minute that dry air IS lighter than wet air.
Drying laundry, a boiling pot, or a hot bath are all likely to cause humidity levels to rise, while ventilating a room properly will cause levels to fall, even though it generally makes the air cooler.
Well, according to Isaac Newton, in his book Opticks, (and USA Today) humid air is actually LESS dense than dry air. It makes sense. If humid air didn't rise, why would rain fall from the sky when the temperature drops? So, in a home, humid air rises up, not down.