There are a lot of factors that can cause mold and mildew problems in homes today. However, moisture is always associated with it. Most people confuse air-transported moisture with heat-transported moisture. In most cases it is air-transported moisture that leads to moisture problems in homes today. The following explains the relationship with energy conservation concerning mold and mildew. However, it must be pointed out that this is not the only cause for mold and mildew problems in homes today.
Equilibrium Relative Humidity (ErH%) is widely misunderstood. Nature always seeks balance or to equalize things. Air or objects that has a lower humidity than other air or objects, will extract the humidity from the other air and objects until the humidity levels are equal in the air and objects. Nature's way of balancing or equalizing the amount of humidity in different air masses and objects is exactly how moisture is removed from our homes.
The average home today has a little bit more than one air exchange per hour during the winter months. Energy Efficient homes have even less air exchange. Much older homes that did not have the improvements we do to our homes today had more than three air exchangers per hour. They were referred to as drafty homes because of this.
However, the more air exchange the healthier the home, which is good for the occupants. There is a direct relationship between our energy bills and the air exchange in our homes. The primary source of air exchange in the winter is heating. Whenever you heat air, it expands. When it cools, it contracts. Since the house cannot get bigger or smaller, when the heat comes on and the expansion occurs, it pushes air out of the house. When this heated air cools, it contracts and pulls in fresh air into the house. The higher your energy bills are, the more air exchange there is. The lower your energy bills are, the less air exchange there is.
The higher or lower energy bills are an indication the frequency of the expansion and contraction. Another way of putting this is the cold air outside has less humidity in it than the air inside the home. As the cold air is drawn into the home because of the cooling and contracting of the warm air, this cold air will equalize with the temperature and humidity of the air inside the home. It does this by increasing both the temperature and humidity level of the cold air through absorption, which lowers the temperature and humidity level of the air in the home, until they become the same temperature and humidity level.
Since people want to lower their energy bills and improve their comfort by reducing the drafts in the home, the result is the humidity that would normally be removed because of the greater air exchange remains in the house. In the cooling season moisture problems arise primarily due to over-sizing of air conditioners. Everyone seems to want his or her homes cool in the summer. The homeowner insists that the system be a little bigger just in case there is a hot spell this summer. Contractors have a tendency to over-size units to avoid callbacks and complaints. If we couple this with Energy Efficient homes today, it should not surprise anyone that we are experiencing moisture problems in our homes.
All air conditioner coils (evaporator coil) have a Sensible Heat Factor rating. The area in which you live usually determines this. What this does is determine the amount of humidity it will extract from the household air as it passes through the coil. So what the Sensible Heat Factor rating and the size of the unit do is drop the temperature in the home and at the same time it removes the humidity from the air. When your system is oversized, it will drop the temperature rapidly and remove very little humidity. This is because it takes a considerably longer time for your unit to remove humidity from air than it does to drop the temperature of that same air.
The result is that you end up with a moisture problem in the home. These are the primary reasons why Energy Conservationists, like myself, are blamed for the moisture problems that presently exist in so many homes today. With this in mind, I must point out that many people in this industry from manufacturers, conservationists, building performance experts, contractors and more do not fully comprehend the ramifications of energy conservation as it relates to moisture problems in the home. You as a consumer must educate yourself concerning moisture control when doing improvements in your home. Do not expect that you do not have to do anything just because you bought a brand new Energy Efficient home.
Do not expect that the window salesman or general contractor to be well versed in moisture related problems with the product or service they are providing, especially when it comes to conserving energy. To them this moisture problem is unrelated to their product and/or service. Their defense with these types of problems is that other applications in the home caused the moisture problem. It now becomes an argument based on which came first, the chicken or the egg?
In most cases a combination of applications resulted in the moisture problem. Each application by itself would not have caused a moisture problem but when the two were brought together in your home, the moisture problem arose. The future of energy conservation depends on how well consumers are educated. If we are to reduce our energy bills and increase our comfort, which reduces the air exchange in the home, we must also control the moisture that we produce in our homes. This should go hand in hand, but it doesn't. In promoting energy efficiency, people in this industry do not want to mention anything negative. Stressing a point that helps you avoid problems in the future, to me is not negative. In the winter the thing that removes moisture from our homes is air exchange. Since we are improving or buying new homes that have less air exchange, we must then control the things in our homes that add moisture to it.
For example, fixing plumbing leaks as soon as they occur, making sure exhaust fan ducts are sealed and exit the house. Insulate pipes so condensation does not form on them. And the best one is open your windows once the weather permits after the winter. You would be surprised on how much moisture has built up inside the home over the winter and the amount that leaves the home the first hour when the windows are open. If you use air conditioning a lot, then make sure the unit is properly sized for your home.
The air conditioner when used a lot is the number one means of removing humidity from the home. If you do not use air conditioning a lot, the moisture related problems associated with energy efficiency does not apply. In either case the examples given in heating applies when controlling moisture in our homes. Having a basic understanding about moisture control as related to energy conservation is how I would define Energy Efficient Living. What this explicitly implies is that behavior is as important as conserving energy. The number of moisture related problems in homes today is a direct result of people thinking that taking steps to either lower their energy bills and/or increase their comfort in their homes are unrelated to causing a moisture problem.
In my opinion there is not anything negative about telling someone they have to control moisture in their homes if they intend to reduce their energy bills and increase their comfort. Many problems that in fact discourage the purchase and/or use of energy conservation products and practices could be avoided if this was to be brought to light before someone decided to do something involving energy conservation.
Builders of new Energy Efficient homes, manufacturers of windows, insulation and the air sealing industry would benefit more from being open about their products and services and its relationship with moisture related problems in homes today. Ignoring or denying their products or services is related to moisture problems in the home will do more harm than good for their future sales. Healthy Indoor Environments and Energy Efficient Living in my view should be synonymous. You cannot have one without the other. Energy conservationists should be very concerned about educating people about the consequences to conserving energy and not merely promoting conservation. You could say our future depends on it. Protect America's Forests. This is a link from the Sierra Club.
I support them because they do good work on behalf of everyone. One of the other concerns with SBS is Volatile Organic Compounds (VOC) in the air. This is different from a Carbon Monoxide detector.