Ventilation / Radon Vac Fan
Please choose one of products below...
The Effective and Affordable Solution for
The Radon VAC™
provides the first effective and affordable way to reduce radon levels
in existing homes. The unique system consists of a plug-in fan, exterior
hood and installer-purchased PVC pipe. Because the Radon VAC side wall
system evacuates through the basement side wall, homeowners can avoid
the cost and hassle of PVC pipe run vertically through living areas or
outside of their homes to the roof line.
Requires only a 4" hole through wall. Fan and hood
connect directly to 3" PVC pipe. Just plug in the 6' power cord to
Radon VAC - Side Wall Radon Mitigation System
Tjernlund is the originator and
leading manufacturer of Side Wall Vent systems for gas and oil heaters.
Now, Tjernlund has developed the first engineered solution for Side Wall
Voltage: 120 VAC
Warranty: 10 years
|Dilution is the
The corrosion–proof hood infuses outdoor air into the exhaust to dilute
it. This mixture is further diluted as it is propelled away from your
home in a jet of air.
Perfect for Existing Home Retrofits
Often radon issues are found
in finished homes making the long pipe runs of typical systems costly
and impractical. Side wall venting with the Radon VAC requires only a 4”
hole through the basement rim joist and a fraction of the PVC.
Quiet, Efficient Operation
permanently lubricated ball bearing motor is not exposed to moisture in
the air stream. Uses only 50 watts. Engineered to reduce radon across a
variety of sub-slab soil types (dirt, sand, gravel, etc.). Features 6’
Easily adjust the discharge hood to match your system needs. This allows
the Radon VAC to operate in sub-slab or sump pit installations and with
different pipe runs while always producing a strong stream of diluted
Both fan and hood directly connect to 3” PVC—no rubber couplers needed
as with other fans. Rubber isolated mounting bracket eliminates
vibration transfer and rotates 360° to accommodate any orientation.
Mount vertically or horizontally.
|Sealed Housing for
Custom-fitted gaskets throughout the fan prevent radon gas leakage.
Features heavy duty galvanized steel
housing and powerful backward inclined steel impeller.
|Radon VAC FAQ's
Why terminate on an outside wall instead of above the roofline?
Retrofitting an existing home with a typical EBM fan powered mitigation
system can be expensive and/or aesthetically unpleasing because of the
PVC materials needed to terminate the system above the roof. Many
affected homeowners do not have the funds available to devote to these
traditional mitigation methods which cost anywhere from $1,500 to $5,000
installed. EPA studies show less than 15% of the homes that exceed
recommended radon levels have an active mitigation system.
The Radon VAC requires no exterior PVC saving both material and labor costs
while at the same time minimizing the effects on the home’s appearance.
Why is it typically recommended that the fan be outside or in the
Since sealed fans were not used in original studies, a bias for putting the fan
outside the living space was developed. From a practical perspective fans
installed in the attic stand little chance of being inspected for operation or
serviced. Temperature extremes in attics and in cold weather climates also are
an extremely undesirable environment for operating a motor. Exterior PVC is
susceptible to moisture and freezing problems.
|When using a standard fan to exhaust near the ground level problems can develop
for installations that have restrictive soil densities and/or extensive PVC pipe
runs. At lower flow rates the discharge velocity can drop below that needed to
fight wind loads and propel the gases away from the home’s exterior. Tjernlund’s
adjustable Variable Aspiration Control hood lets the installer increase dilution
and discharge velocity on lower flow applications. This allows for the radon to
be discharged and diluted in a jet of air regardless of soil density.|
Beyond the engineered VAC hood our installation instructions state minimum
distances from doors, windows and fresh air intakes to avoid recirculation
issues. These distances have been used for decades to avoid recirculation of
exhaust gases from side wall vented gas and oil fired furnaces, boilers, water
heaters and fireplaces. See the RMS160 instructions for an illustration with
Is using the Radon VAC against code?
No. The International Building Code (IBC) and International Residential Code
(IRC) do not address Active Slab Depressurization (i.e. Fan-Powered Systems) as
a radon mitigation technique. Some institutions (e.g. EPA) offer guidelines and
recommendations for radon mitigation techniques when using basic fans, but these
organizations do not regulate radon mitigation. You should always follow local
building codes. In absence of these codes follow the IBC and IRC.
-Radon is a colorless, odorless, cancer-causing radioactive gas that naturally
occurs in the environment. It is produced by the decay of uranium in the soil
and rocks below the earth’s crust where it is released into the air and water.
-Radon is measured in pCi/L (picocuries per liter of air), a measurement of
-The average indoor radon level is 1.3 pCi/L while the average outdoor radon
level is about 0.4 pCi/L, but can vary from site to site.
-At an estimated 21,000 deaths per year, radon is the second leading cause of
lung cancer in the United States. Only smoking causes more deaths.
-When radon decays, it expels alpha particles. These small, heavy, electrically
charged sub-atomic particles consist of two protons and two neutrons. If an
alpha particle attaches itself to the chromosomes in a lung cell, it can alter
the way that cell reproduces.
How Radon enters your home
-The amount of radon that escapes from the soil to enter the house depends on
the season, weather, soil porosity, soil moisture and the suction within the
-Radon can seep into your home from the soil beneath it through dirt
crawlspaces, cracks in the foundation and walls, floor drains, pipes and sump
pump pits. If you get your drinking water from a well, it can also be a source
of radon in your home.
-Houses act like large chimneys. As the air in the house warms, it rises to the
attic and exits through cracks, openings and around the upper floor windows.
This creates a small suction (“vacuum”) at the lowest level of the house,
pulling the radon out of the soil and into the house.
-Underground well water can transport the radon from the soil into the house at
any time when running water (e.g., taking a shower, doing laundry, washing
dishes, etc.). The EPA says it takes about 10,000 pCi/L of radon in water to
contribute 1.0 pCi/L of radon in air.
-If your water comes from a city supply, there is no need to worry about radon
in the water. When radon in water is stored in a reservoir for more than 30
days, the radon decays away to practically nothing. Every 3.825 days half the
radon disappears through natural radioactive decay.
Testing for Radon
-Testing is the only way to know your home's radon levels. There are no
immediate symptoms that will alert you to the presence of radon. It typically
takes years of exposure before any problems surface.
-There is no safe level of radon. The EPA recommends mitigating radon in a home
when levels are at, or exceed, 4.0 pCi/L. In addition, the EPA says to consider
action if the level is 2.0 to 3.9 pCi/L.
-Testing should be done in the lowest level of the home that is regularly used.
-Short-term tests are a quick and inexpensive way to measure for radon in a
home. They are typically left in place for 3 to 7 days.
-Long-term tests, often called an “alpha track,” should be left in place for a
minimum of 90 days and up to 12 months. Long-term tests provide results that
reflect the average amount of radon in the home during a year.
-Retesting should be done every 2-5 years or if any major changes to the home
have been done (e.g., finishing a basement, addition, new heating system or
adding central a/c).
-Even homes in areas considered at low risk for radon can have high radon
levels. About 15% of homes in the U.S. have radon levels above 4.0 pCi/L.
-All types of homes have radon, even new construction. Do not assume that just
because your neighbor’s levels are low, that yours will be also.
-Changes in season, temperature, rainfall, wind and barometric pressure can all
affect the radon concentration level.
-The main goal is to make the exhaust vent a better “vacuum” than the house is.
-Active Soil Depressurization is where a fan is used to exhaust radon from the
home. There are 6 different types of ASD: Drain Tile Depressurization, Sump
Depressurization, Baseboard Depressurization, Block Wall Depressurization,
Sub-slab Depressurization, and Sub-membrane Depressurization.
-Drain Tile Depressurization is used where drain tile is present in an
application. The mitigation system is tapped into the drain tile tube around the
perimeter of the house.
-Sump Depressurization is also used where drain tile is present. This system is
tapped into the sealed sump pit cover to pull radon out through the drain tile.
-Baseboard Depressurization may be appropriate where a French drain is present.
This option is rarely used today.
-Block Wall Depressurization uses the hollow block wall foundation. The system
is piped into the block wall to pull out radon.
-Sub-slab Depressurization is used in 90% of all radon mitigation systems. This
involves drilling a hole through the concrete slab to pull radon out below the
-Sub-membrane Depressurization is used where a dirt floor crawl space is
present. The floor is covered with thick plastic sheeting, which is then secured
and sealed. The PVC is inserted below the plastic to pull the radon from the
-Passive Soil Depressurization is where no fan is present. PVC pipe is used to
create a natural chimney for radon to vent through. PSD is commonly used in
Radon Resistant New Construction and almost never used in existing homes.
-Radon Resistant New Construction (RRNC) is a new building code requiring all
new homes to be built with additional steps taken to prevent radon infiltration.
The 5 main steps of RRNC include: 4” of coarse gravel below the foundation slab;
thick plastic sheeting above the gravel; a 3” or 4” PVC pipe run up through
conditioned space from below slab to above roof; all openings, cracks and
crevices are sealed with polyurethane caulk and a junction box is installed in
the attic for use with a fan.
-Seal up cracks and openings in basement floors, foundation walls, openings
around pipes, etc. to prevent radon infiltration. If a home has a crawl space,
install a vapor barrier over the bare soil.