Posts Tagged ‘ventilation’
Nearly every homeowner has encountered the term “radon” either during the selling or purchasing process. Homeowners have good reason to be aware of the potential presence of radon in their home, to test radon levels, and install radon ventilation systems if the radon levels are high. Many prospective home-buyers, however, choose to forgo radon testing prior to purchasing their new home, because they are uneducated or misinformed regarding what radon is and the detrimental long-term effects it can have on the health and vitality of their families.
What is Radon?
Radon is a naturally-occurring, colorless, odorless, tasteless gas that is highly radioactive and extremely dense (nine times more dense than air!). It was discovered in 1899-1900 by two European physicists, Ernest Rutherford and Friedrich Ernst Dorn. Although there are many forms of radon, Radon-222 is the type that occurs most frequently in the environment.
Radon can be highly concentrated in groundwater and in the ground under where a building is constructed; the ingestion of this contaminated water, and the inhalation of the radon particles released from this water, are the two primary ways in which people are exposed to this radioactive substance. As radon decays, the particles attach to microscopic airborne materials, like dust, which facilitates its inhalation by humans.
When it is determined that a house has unsafe levels of radon gas, what options are available for radon mitigation? How can this poison radon gas be safely removed from the house?
The radon mitigation options appropriate for a house depend on the construction type of the house. Houses with basements, slabs, or crawl-spaces may require different techniques. For houses with basements or slabs, the most common technique for radon remediation is active subslab suction which may also be called subslab depressurization. This approach places one or more suction pipes through the slab into the material underneath the house. These pipes are then connected to a fan that draws the radon gas through the pipes and vent it above the house where it is safely dispersed.
There are other variants of this approach available as well. These variations use existing features of the house to connect to the suction pipes and provide for radon evacuation. Options include using existing perforated pipes or drain tiles around the foundation of the house, using a sump-pump hole, or using the space inside of the foundation walls found in block-wall foundations to remove the radon.
For houses with crawl-spaces, a similar technique for radon remediation is available. This approach, called submembrane suction, places a plastic sheet in the crawl-space directly above the ground and then uses a suction pipe and fan to draw the radon out from underneath the plastic and vent it to the outside. It is possible to attempt this without the plastic sheet, but it is less effective and may cause other airflow issues in the house, including increased energy costs.