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Underground Home Ventilation

When you walk through a bright and airy underground home, it might not dawn on you at that time, but there are ventilation systems at work there, to keep the air fresh. Subsurface habitats need air exchange systems due to the buildup of CO2, mold spores, tobacco smoke and sometimes even radon in underground areas.

Ventilation for underground home

Most earth-sheltered homes have state of the art systems for incoming air, so that it can be properly filtered.

As much as people who live "down to earth" lifestyles like to keep things simple, a ventilation system really should be at least partially automatic.

Exchange This, Please ...

Underground homes benefit greatly from ventilators that recover energy. They are called air to air heat exchangers, and they remove the polluted or stale air from your home, replacing it with fresh air from outdoors.

In order to conserve the most energy, these ventilators pass the warm air moving outdoors through a component inside, a heat exchanger. There, heat that is headed outdoors is actually transferred into the incoming air, which is cool. This process will keep you warmer in the winter, and save a lot of energy, since your heater won't be needed for warming incoming cold air.

Humid Beings ...

During the summer months, the outgoing air works to cool the warm, incoming air, which maintains comfort in warmer weather. Ventilators that work on the energy-recovery system can be run with humidistats or timers. Although they tend to remove any excess humidity, you can even set them up to add more humidity to the air in your home, as needed.

Underground House and Ventilation

When you're looking into purchasing an energy-recovery ventilator, keep in mind that they may sound more technically difficult than their workings actually are. The ventilator you want is different from a heat recovery ventilator. In the unit you want, the heat exchanger will transfer some water vapor into your incoming air. Heat recovery ventilators only transfer heat.

You can keep the humidity of your earth-sheltered house more constant when your unit transfers some moisture to the air coming in, which is generally less humid. This helps your home to maintain a more constant level of humidity. The core of the heat exchanger will also stay warm, which minimizes freezing problems in colder climates.

Breathe Light Into the Room ...

Some earth-covered homes also feature skylights that can be opened, which is a much simpler way of allowing air flow from the front of the house to the back. But that system only works when someone remembers to open those skylights. You may also see conduits or tubes in the front of the house (below the level where they would affect the natural look) that run from the front to the back of the house.

Many people who dwell in earth homes also have plants, to bring nature in. Plants generate oxygen from the carbon dioxide we breathe out, though not on a large enough scale to ventilate an entire house (the Biosphere in Arizona discovered this quickly). Some homeowners may use a combination of systems, including a "passive stack" system.

Earth Berm House with Vent on Top

For smaller homes, tubes or conduits can move air enough to vent the structure, and with the temperature differences, it works fairly consistently. Homeowners will sometimes rig a mechanical assist to this system, to be sure of proper ventilation at all times.

Conclusion ...

When planning and designing your underground house be sure your contractor covers the ventilation system in detail upfront. You'll breathe a lot easier if you do. :)

Written by Kevin Knatloa

First Published on November 05, 2012

Updated November 22, 2013


External Links

Heat Exchangers and Energy Recovery Ventilators