It seems just about everybody has basement humidity problems. Where does all that water come from?
Humidity can come into your house simply in the air, in spring or summer straight through open windows and doors, and straight through air leakage when the heat or air conditioning is on. For example, poorly sealed windows and doors, cracks in surface wall plaster in older houses, cracks in upstairs ceilings, or poorly sealed attic hatches can all be sources of unwanted surface air. Anyone that draws air out of your house, such as a wood fire, kitchen fan, gas hot water tank, or a low- or mid-efficiency furnace, will also draw air in straight through these poorly sealed areas.
So one way you can cut moisture is to restrict the flow of fresh air, especially during humid weather. This will not only cut down on humidity problems, but will save on your heating and cooling bills as well.
Water can seep straight through basement walls from outside. You need to direct surface water away, seal the surface of the foundation, heighten drainage below the foundation, and possibly seal the inside of the masonry wall as well.
Human activities such as breathing, sweating, showering and cooking, can also originate moisture when the house is ended up. This can add as much as 20 gallons of water a day to your house.
Surface water will find its way down
Water pooling in your driveway, or pouring out of an eaves trough, finds its way downhill. If there is porous soil around your house, or a crack between the pavement and the house, the water will flow straight through the soil or crack until it reaches the water table or is otherwise stopped. Once it cannot flow down, it flows across, which is when it starts seeping straight through your foundation.
So keep surface water from collecting around the walls of your house. Keep eaves troughs cleared of leaves and properly angled, and downspouts in working order with their outflow directed away from the house. Your driveway should slope away from your house, or you can run a bead of mortar along the wall between the driveway and the house to keep water that accumulates in the driveway from working its way down along your foundation walls.
Gardens, lawns, and other surfaces should also slope away from your home, and if you have a sump pump it should drain well clear of the house as well.
Groundwater finds its way in
Keeping groundwater out is a bit more animated and can be expensive. A waterproofing contractor can dig a trench to your foundation from outside, and apply a waterproofing compound to the surface below-ground masonry. They should also backfill the trench in with gravel and sand to heighten drainage, and they can install drainage tile at the lowest to draw the water table down below the floor of your basement.
A cheaper option, if you have exposed masonry in your basement, is to scrub down the masonry to a hard, clean surface free of grit or mineral sweat, and use a parging compound - a thin mortar slurry - to heighten the waterproofing on the inside of your walls. This works for minor humidity problems but is not a explication if you have serious basement moisture.
Reducing moisture yield in the home
Any moisture you can avoid producing will help cut down on humidity problems. You can't stop breathing, but you can cook with pot lids on, and run the range hood when boiling water; you can have shorter showers or run the bathroom fan when showering; and watch out for aquariums, houseplants, ornamental fountains, and other possible humidity sources.
Take out the humidity but not the heat
If you have humidity problems in the winter and your home is recently built and well insulated, it may be that your home is sealed too tight. A well sealed home saves on heating costs, but if it is too well sealed humidity will build up, as will off-gassing from plastics, woods, carpets, and other materials that may harm your health. A heat exchanger might be a best choice than a dehumidifier if this is your problem. Heat exchangers allow air to flow in and out of your house, while capturing most of the heat on its way out.
Energy productive dehumidifiers primer
Let's cover how humidifiers work, their capacity rankings, how power productive dehumidifiers are rated, and how to select the best one for your situation.
Dehumidifiers remove moisture from the air using a compressor, condenser coils, and fan. They work much like refrigerators, except that their cooling power is used to dry water out of the air. They have a humidistat which keeps them running until the moisture reaches a set lower threshold, or until the tank is full, whichever comes first.
Dehumidifiers are ranked based on removal capacity - how much water they citation from the air in a day - and tank capacity - how much water they hold. In the Us, removal capacity is rated in pints per day and capacity is rated in quarts. In most other countries, removal capacity is rated in liters per day and capacity in liters.
Once your tank is full, it will not citation any moisture until you empty it. If you place your dehumidifier near a basement floor drain, you can run a hose from the tank to the drain, so that you never have to empty the tank. (Most dehumidifiers come with an opening for a hose.) If running a hose isn't an option, make sure you buy a unit with adequate tank capacity.
Energy factor rankings
The power factor for dehumidifiers is the number of liters or pints of water removed from the air per kilowatt hour (kWh) of electricity used. The higher the power factor value, the more productive the dehumidifier is. So bigger is best - unlike the efficiency rankings for other types of appliances.
Energy Star dehumidifiers have power factors fluctuating from 3.56 (the best) to 1.2 (the worst) with a average rating of 1.62. Only two manufacturers, Therma-Stor Products and Munters Corporation, make dehumidifiers with a factor of more than 2.2.
But bear in mind that an power Star rating does not mean the dehumidifier is undoubtedly power productive - just more power productive than some of the others in its category. For example, power Star rated dehumidifiers can have an power factor as low as 1.2, while the best power factor is 2.02 and the worst for a non- power Star rated dehumidifier is 1.0.
Always buy a dehumidifier that can handle the dampness in your home. You will typically not wish a pints-per-day rating greater than 25 unless your basement is extremely wet and at least 1,200 square feet in area, wet and at least 1,500 square feet, or normally damp and musty (but not wet) with at least 1,800 square feet.
On the other hand, higher capacity power Star units are typically more power productive because of the different capacity thresholds by which dehumidifiers are rated. So don't skimp and buy too low a capacity unit - overestimate rather than underestimate.
If your basement is very cool, get a dehumidifier model that can withstand lower temperatures. Otherwise, the cold basement will cause frost buildup on the coils, which will make them less productive and may cause rapid on-and-off cycling of the motor. If you hear this behavior, turn the dehumidifier off until the ice has melted and fallen away. If the behavior persists you may need to switch to a unit designed for cooler temperatures.
Cutting power costs, with Anyone dehumidifier you use
If your basement is damp, and you're running the dehumidifier, keep the doors to the basement ended so moist air doesn't creep in from upstairs.
Keep your dehumidifier coils and fan clean and free of dust. Some dehumidifiers include a washable air filter you can clean to remove dust build-up; if you have one, keep it clean.
If you replace an old dehumidifier with a new, properly sized power Star rated dehumidifier, and you tackle your humidity sources as best you can, you could cut your power use by half or even two thirds over what you were paying before for the same humidity control. But more likely, you'll use a wee less power with a change dehumidifier, while getting much best humidity control, or you'll use more power (if you did not have a dehumidifier) but you will be far more comfortable.
Given how much evidence is turning up about the ill condition effects of indoor humidity and the resulting mold and mildew, you'll assuredly advantage from taking control of your humidity problems and buying an power productive dehumidifier. You can't put a price on good health!
energy efficient Dehumidifiers - Tips For Cutting Humidity Without Breaking the Bank