Geothermal air conditioning and Canadian wells
Underground temperatures remain steadier than surface air, so guiding air through buried channels into a home can provide notable cooling in summer and warmth in winter. Depending on the site, energy use for heating and cooling can be reduced substantially or even avoided. Geothermal air systems offer a reliable option to address seasonal energy shortages and are often ecological and economical choices.
Canadian wells, also known as Provence wells in some regions, exemplify geothermal air conditioning and are gaining popularity due to their straightforward setup.
These systems rely on pipes placed beneath a home and connected to interior spaces to regulate indoor temperatures. Since they do not draw power to operate, the only ongoing cost is installation. Afterward, a home’s cooling and heating expenses typically drop, translating to meaningful savings on monthly bills.
Typical temperature differences in a Canadian well show winter and summer dynamics that benefit the living space. In winter, underground air tends to be warmer than indoor air; in summer, it is cooler. This creates a natural heat exchange that warms the interior in cold months and cools it in hot months without conventional electricity use.
Bioclimate strategies like Canadian wells improve a building’s energy efficiency. While installation is cheaper during new construction, retrofitting a system can still deliver clear benefits and lower operating costs.
The surface temperature is influenced by environmental conditions, but at a depth of two to three meters, temperatures generally remain constant, typically within a comfortable range for indoor environments. This principle is supported by industry summaries that note stable underground temperatures can sustain comfortable indoor climates year-round.
Canadian wells involve laying channels two to four meters deep and about 35 meters long, circulating air through these ducts. The air, in contact with the underground environment, adopts its temperature before entering living spaces, with optional supplemental heat as needed.
The notion of a stable year-round underground temperature makes it possible to offset typical heating and cooling loads. A constant underground temperature can be found around depths of 15 to 20 meters, while shallower depths often reach near-optimal comfort ranges of 18ºC to 24ºC for many homes. This dynamic can help reduce or eliminate the need for electric heating or cooling, depending on climate and system design.
Soil assessment and preparation
Before installing a Canadian well, soil conditions are examined to determine thermal conductivity and related properties. Understanding soil behavior helps maximize performance and anticipate any potential drawbacks.
Soil thermal conductivity depends on porosity and saturation. For instance, granular soils with clay or silt typically conduct heat more effectively than sandy soils. Clean sandy soils have lower conductivity when dry but improve when saturated, and water content strongly influences both conductivity and heat capacity. This soil analysis informs decisions about depth, channel length, and insulation needs.
Winter performance
During winter, outdoor temperatures are cold, but at modest depths the soil temperature sits higher than outdoor air. As outside air is circulated through underground ducts, it warms up before reaching living spaces, reducing the need for electric heating and improving indoor comfort.
In suitable conditions, electric or auxiliary heating can be significantly reduced or avoided altogether, lowering energy bills and carbon emissions while maintaining a comfortable home environment.
Summer performance
In summer, surface temperatures rise while underground air remains cooler. Air moving through the buried channels cools before entering the home, enhancing comfort and cutting back on air conditioning or ventilation demands.