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NetZero Energy Architects "Hybrid" Home Energy Design

Solutions that Reduce Home Energy Use While Increasing Quality and Comfort.
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Crawl Space Facts
Passive Geo-Exchange Crawl Space Conversions

Mechanically Ventilated Crawl Spaces”

The Earth’s ambient / passive geo-exchange energy contribution of a home with the crawl space sealed off from exterior. The idea behind Geo-exchange / crawl space is similar to Geo-thermal energy with the earth.

  • Reduce utility bills

  • Cleaner and healthier air quality for your home

  • Less impact on the environment

There is an energy source from the earth’s temperature within your home’s crawl space.

By encapsulating your crawl space, you can significantly reduce your homes heating and cooling loads. The data shows that there is an average between 15-20% energy savings.

This is a new business focusing on crawl space / geo-exchange opportunities. The process seals off the crawl space vents, and introducing fresh air through a heat exchanger transferring the incoming fresh air’s temperature to the exiting exhaust air.A very simple and cost effective way to take advantage of the earth’s consistent 55-60 degree temperature.

Energy Recovery Ventilator (ERV)


Earth’s ambient / passive geo-exchange energy contribution,

In the winter

The sealed up crawl space blocks cold air from entering the home envelope thus cooling down your house from the underside. It will absorb radiantly from the earth keeping your house warmer, saving you energy and therefore money for heat.

In the summer

The sealed up crawl space blocks out the hot exterior air and utilizes the cool ground for radiant loss to the earth to keep your home naturally chilled.

In addition, energy will be saved, because of the reduction of building envelope heat gain / loss, which is equivalent to the area of the home’s foot print.

The Passive System Least Exspensive

  • Seal Up exterior vents

  • Mechanically ventilation to be provided with an air to air heat exchanger called an Energy Recovery Ventilator (ERV) transfer is typically 75-90%

  • Studies show 15-25% utility bill savings, depending upon environmental factors

The Hybrid systemThe most efficient system

When combined with the homes mechanical HVAC system, proper insulated, you will create an energy source of passive / geo-exchange.

Requirements are:

  • Air tightness of the cavity being used as an air return / plenum. The crawl space has been encapsulated from moisture and air infiltration, meeting code requirement of an approved continuous vapor retarder for mechanically ventilated crawl spaces.

  • Insulate at the rim / floor joist, and the seams of the wall framing above the concrete foundation

  • Alteration of the mechanical return ducting system. In some cases this only requires minimal work.