Florida Mitigation Standards- - - Ventilation and Pressurization Radon Control
WHAT IS THE FLORIDA MITIGATION STANDARD LIMIT FOR VENTILATION AIR IN VENTILLATION
PRESSURIZATION RADON MITIGATION INSTALLATIONS ?
The Florida Mitigation Standard requires that the outside air introduced by
the radon mitigation system not cause the ventilation rate of the affected building
to exceed the MINIMUM ventilation rate recommended by ASHRAE 62-1989 "
Ventilation for Acceptable Indoor Air Quality".
In the case of residential facilities including private dwellings, single and
multiple, Table 2.3, page 11 applies. This states that for living areas the
MINIMUM recommended ventilation rate is 0.35 air changes per hour but not less
than 15 cubic foot per minute (cfm) per occupant.
The "not less" than quantity is determined by taking the number of
bedrooms multiplied by 2 assumed occupants in each, multiplied by 15 cfm. Therefore,
a 2 bedroom dwelling would have an ASHRAE recommended minimum ventilation rate
of 0.35 air changes per hour, but not less than 60 cubic feet per minute total
air flow from induced ventilation air.
The same dwelling if assumed to have a floor area of 1000 square feet and a
ceiling height of 8 feet will yield a total volume of 8000 cubic feet. A 0.35
air change per hour ventilation rate requires a 47 cubic feet per minute induced
In this case the 60 cubic feet per minute ASHRAE minimum based upon 4 occupants
at 15 cfm each would be the limiting induced air flow for any mechanical ventilation
or pressurization radon mitigation system.
This information has been confirmed by means of phone conservations with Mr.
Walter Klein, Florida Department of Health, Radon and Indoor Air Section, 800-543-8279.