Build By Design :: Geothermal (part 3)

While we think the most significant benefits from the perspective of the human race of a geothermal system are environmental, we suspect that the economic benefits speak loudly to most families, especially with today's energy prices. So let's start there.

While your mileage may vary, it is clear that operating a geothermal heating and cooling system will cost substantially less than a comparable conventional system. Depending on the existing system to which it is compared a geothermal system will use between 30 to 70% less energy. Do you know how much you pay to heat your home each month, or to cool it in the summer? If you did you might be shocked. If your home represents a typical system, the cost of running your system—whether it uses electricity, natural gas, propane, heating oil, or even wood—is likely to drop by at least 30%. But the savings don't stop there.

You might have purchased a combination furnace and air conditioner in the past. You'll note that these are actually two separate appliances, even though they use the same ducts to deliver hot or cold air. The heating unit uses either an electric coil or burns a fossil fuel such as natural gas to heat the air which is then blown through your home. The air conditioner uses the principle of a refrigerator just like the geothermal. So, with a conventional system you need a furnace and an air conditioner to heat and cool your home.

Geothermal, however, uses the refrigeration unit for both heating and cooling, reducing the number of expensive parts that can break.

Conventional furnaces have a life span of 15 to 20 years. Air conditioning units have a life span less than that. Geothermal units are very simple. Because they let the ground beneath your home do the lion's share of the work they have less work to do, so they have fewer moving parts and less wear and tear than conventional systems

Geothermal systems have a life span of 30 years or more¹. But here's even better news: your payback on the cost of a geothermal installation is typically less than six years, and as little as two². You could see a two to six year payback with a 30 year life expectancy!

It's great to save money but even better to save the environment. You're going to buy a furnace and maybe an air conditioner anyway. Why not buy the greenest technology available? Read on...

The direct-exchange geothermal system simply does not combust any fossil fuels, and the electricity used by the system is minimized by using the heat from the ground.

Let's start with this: According to the Environmental Protection Agency geothermal heat pumps are among the most efficient and comfortable heating and cooling technologies currently available for homes (or any other building.) In a 1993 report titled Space Conditioning: the Next Frontier, the EPA concluded that geothermal heat pump technologies represent a major opportunity for reducing national energy use and pollution, while delivering comfort, reliability and savings to homeowners³. Why is that? Heat pumps in general are highly efficient since they "transfer" heat rather than "create" it from a combustion process. Ground-source (geothermal) heat pumps enjoy the extra advantage of a stable heat source or heat sink—the earth⁴.

Because of the lower energy requirements of the geothermal system greenhouse gas emissions associated with their use are 55 to 60 percent lower than from standard air-source heat pumps⁵. It is estimated that "Replacing an HVAC system with a geothermal system will reduce the amount of pollution equivalent to not driving your car 140,000 miles."

In summary, geothermal provides heating and cooling with less environmental impact than any other heating and cooling system available. In fact, the EPA concluded that well-designed and properly installed high-efficiency geothermal heat pump systems produce less environmental harm than any other space conditioning technology currently available⁶.

In fact, according to the EPA, installing a geothermal system is like planting 750 trees or taking two cars off the road⁷.

Yes, let's not forget safety. We don't think of heating and cooling systems as dangerous, but we know that in rare instances they can be.

Because no fossil fuels are used in the geothermal system there are none to leak out, such as the explosive liquid natural gas used by conventional systems. There is no open flame and no smell.

The combustion of any fossil fuel produces dangerous and toxic carbon monoxide. Because geothermal systems do not burn fossil fuels, they do not produce this deadly gas.

In cooling mode a geothermal system requires significantly less power than a conventional air conditioning unit. High-voltage, high-current appliances represent the greatest risk of electrical fire in our homes. Because the electrical draw required for a geothermal system is so much lower than a conventional system the likelihood of an overloaded circuit is significantly reduced.

You want to save the planet, sure, but you don't want to make your family suffer for it. With geothermal systems you don't have to. Read on...

Geothermal heat pumps provide higher comfort levels than traditional space conditioning equipment. By using a highly stable source of energy to heat your home the geothermal heat pump maintains a steadier, more comfortable heat range than a conventional furnace or air conditioning. Geothermal heat pumps also cycle much less often than fossil furnaces, creating a consistent indoor temperature with comfortable relative humidity.

Geothermal units naturally deliver a 50% relative humidity level, a very comfortable level that for most people. And that humidity level is maintained at a very consistent level in all modes of operation.

A geothermal system in heating mode does not have a burner, one of the noisiest components of your existing furnace. In cooling mode, it has a much smaller compressor than a conventional air conditioner as the incoming refrigerant is already as cold as it needs to be to cool your home. Unlike a conventional air conditioning unit, it does not need to lower the temperature of the refrigerant by 40 degrees or more. Therefore, a smaller, more efficient compressor running far less often is sufficient. Think of how quiet your refrigerator is; that is about what you can expect from your geothermal system.

A geothermal system is so quiet, in fact, you normally won't know when it's running.

With a geothermal system you have no flames, no fuels and no odors; those with environmental sensitivities will be very glad to know that. The more consistent humidity level produced by geothermal systems reduces the growth of dangerous mold and allergens. Plus, your geothermal system can be fitted with a high-efficiency filter for an even healthier environment.