basement humidity

[transferguy]

posted by: chrisb

What level should I set my dehumidifier for the basement?
I just bought a new one and I think it might be too small. It's a 50 pint unit. It will not bring the level down below 55%. I have all the windows closed but no AC.

[transferguy]

posted by: jeff1

Where to position your dehumidifier...

The dehumidifier must be operated in an enclosed area in order to be most effective. Close all doors and windows and other outside openings to the room, since the size of space in which the dehumidifier will operate effectively is greatly influenced by the rate at which new moisture enters the room. Your dehumidifier is designed to operate on ordinary household 110/120 volt 60-cycle alternating current. A 15 or 20 ampere fused separate circuit, serving only this appliance is required. When locating the dehumidifier, be sure that it is placed so there is no restriction to air flowing either into the coils at the rear or from the front grille. For the best performance, allow at least 12 inches of air space on the front and back. A dehumidifier operating in a basement will have little or no effect in drying an adjacent enclosed storage area, such as a closet, unless there is adequate circulation of air in and out of the area. It may be necessary to install a second dehumidifier inside the enclosed storage area for satisfactory drying action.

Basement humidity that's too high can create mildew and mold problems. This is rarely a concern in the winter since the colder air doesn't retain humidity, but during a rainy spring or summer the humidity can spike quickly. The basement humidity should be kept at or below about 65 percent during the summer and 30 to 40 percent in cold winter climates

We have 2 smaller units in our basement, we keep them at approx 40-50%.

jeff.

[transferguy]

posted by: chrisb

I have adjusted it to 50%. I will see if it ever shuts off.
It is not going below 59% right now.

[transferguy]

posted by: dkerr

Not sure what kind of system chrisb has but for people with basements and forced air furnace systems would the air conditioning in itself keep the humidity in an acceptable range? Or is further control keeps required? I am replacing my furnace later in the summer as well as installing central air-conditioning, just wondering what works the best, as far as whole house concerns, or do you always end up with humidity differences in each section of the home? Can effective humidity control be done at furnace?

The fact that chrisb humidity does not ever get to where it is set does that mean the capacity of the unit is not great enough to meet the demand?

[transferguy]

posted by: suemarkp

Yes, if the desired humidity level can not be reached, then the dehumidifier needs to be larger. Maybe you need two instead of one large one if the basement is large. Also make sure to empty the water bucket, or even better make sure it dumps directly into a drain.

Running the AC lowers humidity. But it may not be pushing much dry air into the basement. I don't think you're going to find any rule, it will be trial and error based on how damp your basement is, how much central heating/cooling can be put there while still keeping it comfortable, and how large and how many dehumidifiers you have.

Central heating and cooling both lower the humidity. In cold areas, many houses have humidifiers. A damp basement can help humidify the rest of the house in winter if you can circulate enough air through the basement. The problem with that it the basement usually has the lowest heat loss or heat gain because of the relatively constant earth temperature around its walls. So the square footage of the basement doesn't need as much heating/cooling airflow as the rest of the house. Running a central HVAC fan continuously can help balance the humidity between different parts of the house, especially if there are return vents on every level.

I've seen new heat pump water heaters. I would think those could act like a little air conditioner and reduce humidity. Was considering trying that at a house where I have a basement, but I sold that one.

[transferguy]

posted by: chrisb

Heating system is hot water baseboard. I am thinking this unit is too small. It will not bring the level below 59% on its own display.
The unit is dumping into the drain. No bucket.

The unit is a 50 pint unit.

[transferguy]

posted by: myrah paul

I suppose you have a smaller unit then what is required. The alternative could be you can have 2 on the same place. I think will help you a lot.