When you begin to seal and insulate your home, moisture can become a bigger problem. A constant supply of moisture can lead to mold, but non-constant moisture can lead to problems with wall coverings and more.
I have been thinking about installing a bathroom vent in my home. Since it is an older home, the bathroom window was meant to be opened to release the moisture. The problem is that not everyone in the family remembers to do this. When colder, no one wants to step outside the shower or tub to a cold room. Bathroom vents were meant to resolve this concern, but many homeowners consider that they are only for odors, so I see moisture problems on my home inspections even when these bathroom vents are installed. The other problem with bathroom vents is that they vent into the attic. You are moving moisture from one part of the house to another, when you really want them to vent out of the house. I may well install this vent soon, but I began to look for other moisture sources in the home.
I found that venting moisture from my bathroom involves more than opening one window. To clear the moisture from that I room, I open the window in the bedroom as well. The cross breeze helps. In the kitchen, I have been steaming and boiling more. In fact frying can add moisture to the home as well. Opening a window in the kitchen can help, but the range vent in your home was meant to exit moisture from your house. That is one reason why you should keep the filters clean, and the unit should work. I have seen people remove this vent, and I am not sure why.
I inherited a 250 gallon fish tank from my father. The other day I noticed that the water level had dropped. I knew that some evaporation may occur, but this was adding quite a bit of moisture to the home. This moisture could be removed by a dehumidifier. Stand alone units are popular, but there are units that can be installed within the air conditioning system. Even a smaller tank could add moisture. Another item that adds moisture to the home is firewood. The wood used to frame a home is dried to make it more stable, but this wood is never completely dry. Firewood on the other hand can have a good deal of moisture, so letting it dry outside in a stack that encourages it to dry can be helpful. In Houston, we do not use our fireplace often, nor do we have large firewood stacks. We buy some firewood, and place it by the fireplace, allowing the moisture to enter the home.
Consider what you have in your home. I have seen table top water fountains in some homes. Washing machines for clothes and dishes can add moisture. What else may you have? There are devices like an HRV (heat recovery ventilator) which can help remove moisture from the home. These can be connected to the forced air conditioning system, but they can be separate. These units have come in and out of fashion, but I am thinking that they may be good to have in our modern homes. The HRV is meant to improve air quality in the home by bringing fresh air into the house, while expelling your older air (the HRV is not meant as a device for expressly ridding the home of moisture). Currently my neighbors are already running their air cooling systems. I have windows open myself. Opening and closing windows at different times of the day used to be common pre-air conditioning, and this habit allowed for good moisture control.
This moisture could be removed by a whole house dehumidifier.
Installing a dehumidification system in the home works. Single units in each room have to be emptied of water, which could be used for your plants, but I think a unit attached in the line of my air conditioning may be a better option. However, like all Houstonians, I do rely on my AC. A method for ridding my house of moisture would be wise. To help make my home more energy efficient, I have sealed my home as much as is possible with an older home, so this does prevent moisture to escape. Something to consider if I want a healthy home is having better moisture control.