Radon OverviewReducing Radon in a Home

Learning Outcomes

Upon completion of this module you will be able to:

Recall the most common method to reduce radon in a home

Identify why you can’t just seal the cracks to keep the radon out

Recognize the difference between a passive and active mitigation system

Learning Outcomes

Upon completion of this module you will be able to:

Identify the rules for vent pipe location in an interior sub-slab depressurization (SSD) system

Determine where the exhaust fan should be installed in a interior SSD system

Recall what a manometer is, and what it does in a radon remediation installation

How To Fix A House If It Has Elevated Levels?

A Mitigation Contractor can: Install a system to reduce radon levels Prevent radon from ever entering the living space

Sealing visible cracks is a basic part of most radon mitigation approaches, but sealing alone is not enough.

Opening doors and windows to dilute the radon may sometimes be effective, but it is not a practical long-term solution.

How To Fix A House If It Has Elevated Levels?

Can’t we just seal thecracks? Radon can enter through

very small openings.

Without affecting house pressures, sealing is not a stand-alone technique.

Methods for Reducing Radon in Air

1. Depressurization Suck air from below basement (slab) Radon does not enter home Radon is exhausted away from home

2. Pressurization Blow air into the basement Push radon gas out Radon gas is diluted

All methods involve sealing foundation openings

Various Foundations May Require Different Methods

Basement and Slab-on-Grade Options

Most common method: Active sub-slab suction system Suction prevents radon from entering home Draws radon from below home and vents radon to pipe(s) Releases radon to air above home It is called an active system if we install a fan in the pipe(s) It is called a passive system if we do not install a fan in the pipe(s)

New homes often have a passive system installed at the time of construction.

Active Sub-slab Depressurization (SSD) Reliable Effective in reducing high radon levels Suction pipes are inserted through the slab into soil

or crushed rock below Vent fan draws radon gas up and

releases it outside, above the roof Works best when air moves easily

under slab

Major Requirements of an SSD System

All components should be clearly labeled “Radon Reduction System.”

If the system has an exhaust fan, the fan must be located outside or above the habitable space of the building. It may be located outside

or in an unused attic.

Major Requirements of an SSD System

Any exhaust fan must be located in a vertical run of the vent pipe.

If there is an exhaust fan, there should be a visible or audible warning device to alert occupants if the system fan stops working.

The vent pipe must end at least 12 inches above the surface of the roof.

Major Requirements of an SSD System

The vent pipe must end at least 10 feet from any window or opening into the house and at least 10 feet from any adjoining or adjacent buildings.

Ties or brackets must secure the vent pipes:

Every six feet in a horizontal run of pipe, and

Every eight feet in a vertical run of pipe

Labeling

The system must be clearly labeled as a “Radon Reduction System”

The contractor’s contact information must be attached to the system

Exhaust Fan: Exterior Installation

Exhaust Fan: Interior Installation

Usually more effective and last longer

Fan must be installed in unused and unoccupied space

Fan may not be installed in basement

Visible Gauge

Manometer: Does not measure

radon Alerts residents if

fan stops working

Discharge Point: Exterior Installation

The discharge point must be at least 12 inches above the surface of the roof

It must also be at least ten feet from windows and other openings, if it not located at least two feet above such openings

Exhaust Point: Interior Installation

The discharge point must end at least 12 inches above the surface of the roof

It must also be at least ten feet from windows and other openings, if it not at least two feet above such openings

Pressurization Methods

Typically used in homes with dirt or stone foundations Locations where depressurization would be

ineffective Types

Home/room pressurization Heat recovery ventilation (HRV), or air-to-air

heat exchange

Summary

In this module we have discussed:

The most common method to reduce radon in a home

Why you can’t just seal the cracks to keep the radon out

The difference between a passive and active mitigation system

Summary

In this module we have discussed:

The rules for vent pipe location in an interior sub-slab depressurization (SSD) system

Where the exhaust fan should be installed in an interior SSD system

What a manometer is, and what it does in a radon remediation installation