Active Dampness Control (ADC) System™
The exclusive Active Dampness Control (ADC) System by HomeAire reduces moisture and radon before they enter the home by drawing them from beneath the home and venting them above the roofline.
An active ADC System quietly and unobtrusively provides better indoor air quality and a healthier living environment while costing homeowners just pennies per day to operate and running continuously with no homeowner maintenance.
ADC System Health Benefits
An ADC System helps to protect home occupants by:
- Reducing moisture, radon and other harmful soil gases
- Preventing more than 1,000 gallons of water per year from entering the home
- Reducing moisture-related health hazards such as insect infestation, mold and mildew
The end result is a home that provides a healthier, more comfortable indoor environment by eliminating some of the toxins and allergens that can cause
- Lung cancer
- Asthma
- Severe allergic reactions
- Headaches
- Sneezing
- And a long list of additional mild or serious allergen-induced symptoms
How an ADC System Works
The ADC system uses a method called active soil depressurization (ASD) that reduces radon and has been found to be effective in reducing moisture entry. The system depressurizes/ventilates a permeable (porous) layer below the slab using
- An ADC-T (see ADC-T),
- A 3-4 inch diameter PVC vent pipe, and
- An inline ADC fan
See ADC System Details for an illustration and more information.
An ADC System is installed in two stages:
Stage 1: This stage of the ADC installation meets the green building requirement for RRNC (Radon Resistant New Construction). Also called a passive system “rough-in,” it includes the installation of an ADC-T in the permeable (porous) layer below the slab and then fitting a 2-3 foot length of PVC pipe into the T before the concrete slab is poured. After pouring the slab and framing the house, some builders extend the PVC pipe through the walls and into the attic. (See RRNC and Passive Radon Systems for more details.)
Stage 2: The second stage consists of activating the system by installing an ADC fan in the attic to provide positive, active control of moisture, radon and other soil gases.
By installing an ADC System during new construction, builders add important indoor air quality features to the home and comply with many green building requirements and standards, including:
- Energy Star® IAP (Indoor airPLUS)
- NAHB Green Building Standard
- Green Building Council LEED-H
- Minnesota's MDH Gold Standard


