Drying damp basements

Drying damp basements with dehumidifiers

Drying Damp Basements - Renovate or Dehumidifier?

There are many obvious reasons why the basement has too high humidity, such as poor insulation, broken windows that no longer keep out the rain, or simply an unfavorable location by the lake. The problem with this high humidity is that, on the one hand, it can lead to mold formation, and on the other hand, the moisture also quickly attacks stored food, shoes, clothes, paper, or electrical devices. The optimal humidity in the basement should not exceed 60%. However, high humidity in the basement is often a multi-layered problem. But how should one proceed with too high humidity?

The goal is clear, the basement must be usable - but the way there is not always so. Before measures are taken, the cause should definitely be established. Is it a matter of

• to address a structural defect, for example a pipe leak or a leaky masonry that absorbs water?
• to have a new building that takes 3 years to fully dry out?
• "a seasonally recurring humidity, e.g. in summer, when the outside air is warm and humid?"
• homemade moisture in the basement from washing, drying, showering, etc.?

There are many causes of high humidity in the basement. In any case, the decision about sensible measures is easier when one knows the reasons.

In these cases, a dehumidifier is a sensible solution:

• for new buildings to bridge the construction drying time
• in the case of seasonally recurring moisture exposure from the outside in summer
• in case of homemade humidity, for example during the drying of laundry or after showering

The incurred costs are manageable in this case, the solution effective.

In these cases, it must be weighed whether a construction measure is sensible or affordable:

• in case of structural defects and damages to sanitary pipes or masonry
• in case of seasonally recurring moisture stress from the inside, for example in garages (also often in bedrooms) due to cold exterior walls.

"Here it makes sense to consider whether to combat the symptoms (too high humidity) with a dehumidifier or to address the cause structurally. A cost-benefit analysis is certainly advisable beforehand."

Calculation example:
If a dehumidifier is being considered, the electricity costs for keeping an average basement dry, depending on the season and size of the area, should be estimated at around CHF 5.- to 20.-, plus the purchase of the dehumidifier at around CHF 600.-. Over 10 years, this roughly translates to a cost range of between CHF 2000.- to CHF 3000.- in total for the device and electricity. The costs of a structural renovation are likely to be several times that amount, but can of course be amortized over a longer period than the 10 years we have assumed in this calculation as the average lifespan of the device.

In some cases, you can avoid excessive humidity in the basement with a few small tricks:

Avoid high humidity in the basement
Often, a basement is not only used as a storage space but also provides a place for a washing machine and dryer. However, dryers have the disadvantage of emitting a lot of water vapor and generating heat. While the devices are running, the room air is heated and can absorb a lot of moisture. When the devices are turned off, the room temperature drops again, and the air can no longer hold as much moisture as it could in a conditioned state. This increases the relative humidity in the basement during cooling, and condensation can form, which first becomes visible on cool walls, windows, or pipes. Hanging laundry in the basement also promotes humidity and leads to elevated levels. However, it is often not possible to hang the laundry elsewhere and move the dryer. Therefore, those who still want to use their basement this way should keep the door of the laundry/drying room closed while washing and drying. On the other hand, this room should be ventilated regularly - especially in winter. Ideally, cross-ventilation for 10 to 15 minutes daily is recommended. In winter, the incoming air from outside is dry and can help to lower the moisture in the basement somewhat. In summer, however, warm outside air burdens cooler basements, so windows should remain closed if possible. Draft ventilation during excessive room humidity is, of course, also advisable in summer, ideally in the evening when the outside air has cooled down.

In many situations, however, extensive ventilation is not possible, whether because there are no windows or a draft cannot be created. Experts then recommend using a dehumidifier, which effectively influences the indoor climate and removes moisture from the air. Then, tumble dryers or hanging up wet laundry are no longer a problem. Modern dehumidifiers are equipped with integrated hygrostats that measure humidity and then ensure that the dehumidifier automatically turns on or off depending on the selected settings. This saves electricity and makes dehumidifying basements a breeze. It is also particularly convenient for users who, for example, hang laundry or put it in the dryer in the morning and then go to work. The dehumidifier does not continue to run unnecessarily, even though it has already fulfilled its purpose.

The choice of the right dehumidifier
In order to optimally reduce the humidity in the basement, the dehumidifier should always be chosen according to the conditions. The size of the room plays a role, as does the question of mobility – if the dehumidifier is to be used in different basement rooms, a stationary device is not the right choice. Furthermore, one should be aware of how cold the room can get in winter and whether to collect the water in the integrated condensate bucket or to drain it directly into a drain.