The dehumidifier should be sized so that it will not have to run full time. No humidifier will last long at that pace; the coils can actually freeze up. It's hard to imagine how a dehumidifier could be too big. Moisture can enter the basement from humid bathroom air or from humid outside air and it usually condenses against the cool concrete walls. Also, inadequate waterproofing on the outside of the walls can allow water to slowly enter through the wall and this can be exacerbated by not enough slope to the grade at the perimeter of the house and the absence of a footing drain. The absence of an adequate vapor retarder membrane under the floor slab can also add to the moisture problem. The fact that the window wells filled up indicates a failure to provide a drain at that location. See if that was included in your contract but omitted. You need to assume all of these issues are problems and then try to eliminate them one at a time. First, get the downspout terminations and surface drainage to run away from the house. Then put a piece of plastic on the concrete slab and tape the edges with duct tape. If moisture gets trapped under the plastic after a few days, the builder probably omitted the code required vapor retarder membrane under the slab. He might also have used a damp sand bed under the slab and that can take a long time to dry. What does the sump pump serve? Is there a perimeter drain? Is it outside or inside? Find out what the exterior wall waterproofing was and what kind of drainage/protection/insulation board (if any) was put over it. Your contractor is obligated under the warranty to do all of this for you since the moisture is excessive but he will probably drag his feet and blame issues beyond his control. If you can't push him, you might might have to get out in front and figure it out yourself. A local home inspector can be helpful.

shelly look at the whole house dehumidiers on iaqsource.com. I recently purchased the Sante Fe whole house unit that handles up to 3300 square feet, Honeywell makes a good dehumidier too. Each vendor makes also make a smaller size unit. If you download the installation manual, it will show you the various ways to hook it up. After posting on the GW, I decided to use the standalone configuration which is quite easy to install. The unit can be installed in the unfisished portion of the basement (presumably in the utlilty room) with the intake and output flex ducts runing to/from the dehumidifier running to the finished portions of the basement. Put the intake on one side of the basement and the output on the other side to get good air circulation. Put a vented door for entry into the unfinished portion to allow air to flow through that room. The closed vented door will buffer the noise and allow air to pass through. You must have a vented door to that utility room if you have gas heat. As far as drainage for the dehumidifier, it is best if you have a drain nearby that runs into your sump pump since these units do pull a lot of water out of the air. But if that is a problem, they make small pumps designed for HVAC applications that allow you to take the output of an AC or dehumidifier unit and pump the water to a drain location. Good luck.

Ventilating a basement can be counterproductive in warm seasons in humid conditions. The basement can be at a temp below the dew point and you will be importing moisture. A dehumidifier is about the only thing you can do in that case. No windows that open? A dehumidifier will make waste heat so it might get hot down there in the summer. You might need cooling too so maybe a window unit can be fitted to a non-opening window so that it can be removed in the cold season if you have one. Where do you live? (What is the climate like?) The need for humidifiers during the winter in temperate climates is greatly minimized if homes are well-sealed. Leaks remove the moisture, that is naturally-generated from living activities, to the outside and let dry outside air in. If you are moving to a high efficiency furnace or boiler from a low efficiency unit, you will have less outside air infiltration. That might be good news for the dry air upstairs, but might be bad for the basement. On the other hand, some basements need dehumidification in the summer and never in the winter. Dehumidifiers are of two types with very little variation within the two types. There are inexpensive portables on the one hand, and more expensive ducted units. The latter are less costly to run and less costly in the long run. Look at the Energy Star web site for efficiency figures. You should only need one if you leave the door open between the two basement rooms and maybe even if you don't. Get a couple of inexpensive hygrometers and monitor the humidity. There will be some good water heater info for you to read at the Energy Star web site too. Gas is cheap right now so as mike_home wrote, there is not much incentive to change it for a marginal improvement. (More efficient gas heaters cost a lot more and don't save that much fuel.) I'd seriously consider hiring a local energy rater to look over your house. They will be familiar with local construction and climate. They will know local energy efficiency programs that might save you some money with rebates or pay for part of the improvements. They can identify the low-hanging fruit for saving money and help you with your moisture problem. www.resnet.us

I attached hose to mine (there is usually connection for hose on a dehumidifier) and ran it through wall (drilled hole) from finished to unfinished side and then to drain. Do you have option to do same?