Air Exchangers
Heat Recovery Ventilation (HRV) also
called Air to Air heat exchangers are a form of active radon
reduction. HRV are generally not designed to remove radon.
They dilute radon by bringing in fresh air from outside, at the same
time exhausting indoor air to the outside. The incoming and
outgoing air does not mix but they do exchange heat by passing close
by one another. One type of HRV works very much the same as
the radiator on your car. The reason for the exchange of heat is to
reduce the cost of heating and cooling outdoor air, HRVs are
designed to conserve energy in your home, they are not designed as
radon reduction units. VSI Environmental has installed several
HRV systems to reduce radon in older (over 100 years old) or unusual
homes, although all of the systems worked we found them to be very
unreliable and high maintenance and discourage the further use of
these systems except as a last resort. It should also be noted
that HRV systems will only work if your radon level is only slightly
elevated, usually less than 6 pCi/l and almost never above 10 pCi/l.