Other Types of Radon Mitigation Methods
Other radon reduction techniques that can be used in any type of
house include: sealing, house/room pressurization, heat recovery
ventilation, and natural ventilation.
Sealing cracks and other openings in the foundation is
a basic part of most approaches to radon reduction. Sealing the
cracks limits the flow of radon into your home thereby making
other radon reduction techniques more effective and
cost-efficient. It also reduces the loss of conditioned
air. EPA does not recommend the use of
sealing alone to reduce radon because, by itself, sealing
has not been shown to lower radon levels significantly or
consistently. It is difficult to identify and permanently
seal the places where radon is entering. Normal settling of your
house opens new entry routes and reopens old ones.
House/room pressurization uses a fan to blow air into
the basement or living area from either upstairs or outdoors. It
attempts to create enough pressure at the lowest level indoors
(in a basement for example) to prevent radon from entering into
the house. The effectiveness of this technique is limited by
house construction, climate, other appliances in the house, and
occupant lifestyle. In order to maintain enough pressure to keep
radon out, the doors and windows at the lowest level must not be
left opened, except for normal entry and exit. This
approach generally results in more outdoor air being introduced
into the home, which can cause moisture intrusion and energy
penalties. Consequently, this technique should only be
considered after the other, more-common techniques have not
sufficiently reduced radon.
A heat recovery ventilator (HRV), also called an
air-to-air heat exchanger, can be installed to increase
ventilation which will help reduce the radon levels in your
home. An HRV will increase ventilation by introducing
outdoor air while using the heated or cooled air being exhausted
to warm or cool the incoming air. HRVs can be designed to
ventilate all or part of your home, although they are more
effective in reducing radon levels when used to ventilate only
the basement. If properly balanced and maintained, they ensure a
constant degree of ventilation throughout the year. HRVs also
can improve air quality in houses that have other indoor
pollutants. There could be significant increase in the
heating and cooling costs with an HRV, but not as great as
ventilation without heat recovery.
Some natural ventilation occurs in all houses.
By opening windows, doors, and vents on the lower floors you
increase the ventilation in your house. This increase in
ventilation mixes outdoor air with the indoor air containing
radon, and can result in reduced radon levels. However,
once windows, doors and vents are closed, radon concentrations
most often return to previous values within about 12 hours.
Natural ventilation in any type of house should normally be
regarded as only a temporary radon reduction approach because of
the following disadvantages: loss of conditioned air and related
discomfort, greatly increased costs of conditioning additional
outside air, and security concerns.
Some houses have drain tiles or perforated pipe to direct
water away from the foundation of the house. Suction on these tiles
or pipes is often effective in reducing radon levels.
One variation of sub-slab and drain tile suction is sump hole
suction. Often, when a house with a basement has a sump pump to
remove unwanted water, the sump can be capped so that it can
continue to drain water and serve as the location for a radon
suction pipe.
Block wall suction can be used in basement houses with
hollow block foundation walls. This method removes radon and
depressurizes the block wall, similar to sub-slab suction. This
method is often used in combination with sub-slab suction.