Build By Design :: Geothermal HVAC (part 1)

The times they are a'changing. Geothermal heat systems have been installed at the Center for Architecture in New York¹ and at President George Bush's ranch in Crawford, Texas² . What is it about a technology that works for a showpiece commercial installation for the American Institute of Architects in Greenwich Village and for the home of the President of the United States on a ranch in Texas? You could hardly have two more dissimilar clients or installations, yet the solution was the same—tap the solar energy stored in the earth.

Geothermal installations work great for commercial and residential applications. They can heat or cool space, provide refrigeration and hot water, all at once with a single system! And all your clients need is the energy stored under the surface of land they already own.

We are beyond the point of any doubt: your clients want green technology. And the simplest change from old legacy systems to new ones that you can make with the greatest impact is to specify geothermal heat pumps for heating and cooling, as well as for refrigeration and water heating, depending on the application. There is simply no other single change you can make so inexpensively with so great a benefit to your clients and ultimately, to your practice.

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 homeowners.³

If you are ready to meet your clients' needs head-on with the best solutions possible, contact us and let us partner with you for very satisfied customers. Read on for the benefits of incorporating best-practice green technology into your own practice. And please, point your client to our consumer link on this site for an explanation of geothermal that is less complicated than what we've prepared for you.

We believe passionately that geothermal heating and cooling is an elegant solution. An elegant solution "...is one in which the maximum desired effect is achieved with the smallest, or simplest effort. Engineers, for example, seek the elegant solution as a means of solving a problem with the least possible waste of materials and effort."⁴

As you will learn in this section, because geothermal systems move energy from the earth rather than create it through combustion, they deliver 3 to 4 times as much energy to your application as they consume.

Moreover, they produce no greenhouse gases and emit no pollutants.

Now that is an elegant solution indeed.

The initial cost of a geothermal heat pump system is higher than a conventional system, but according to the EPA most users experience savings of between 30 to 70% on their heating and 20% to 50% on their cooling costs over conventional systems⁵. In commercial applications, of course, that translates directly into lower operating costs and therefore greater facility value. In homes—particularly custom homes—demonstrable monthly savings will equate to superior marketability upon resale.

By including green technology in general and an EarthLinked^® geothermal system in particular, you will enhance the value of your clients' properties by far more than the slightly greater incremental cost.

A study by the EPA concluded that ground-source heat pumps are up to 72% more efficient than electric heating and air conditioning systems.⁶

Geothermal heat pumps are far more energy-efficient than conventional air-source conditioning systems. What do we mean by that? We measure "energy efficiency" by how much energy is delivered compared to how much is consumed. Most geothermal heat pumps have a coefficient of performance (COP) of 3 to 4, meaning that by using the solar energy stored on site below the surface, geothermal heat pumps deliver 3 to 4 times as much energy as they consume. By contrast, the very best natural gas furnaces only have COPs of 0.9 to 0.97. ⁷

How can this be? Conventional furnaces first have to create the heat that they then blow or radiate into the space to be conditioned. They create the heat through the process of combustion. No matter how good the technology is, there is always some loss of energy potential in the conversion process. By contrast heat pumps in general are highly efficient since they transfer existing energy 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 earth. ⁸ In other words, rather than having to create the heat, geothermal heat pumps simply steal it—OK, borrow it (after all, they put it back in summer)—and only need to consume enough energy to move the heat, rather than create it.

At the end of the day, the success of your practice depends on your clients' satisfaction. They turn to you for expert advice on how to make their business as efficient as possible or their home a sanctuary from the world. To the degree that you accomplish this, you will end up with happier client and get more referrals and more repeat business. Besides the environmental benefits, geothermal heat pumps have two major advantages over conventional heating and cooling systems: lifetime cost, and perceived comfort.

Geothermal heat pumps cost more to install, so how do you convince your client that it makes sound fiscal sense? Geothermal heating and cooling has three major fiscal advantages: lower energy consumption, low maintenance costs, and longer life.

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. According to the U.S. Department of Energy the energy consumed for heating and cooling our homes accounts for 53% of the energy delivered to American households. Water heating accounts for another 17%, so you can see that combined space heating and cooling and water heating account for 70% of our residential energy use nationwide! ⁹

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 have probably specified a combination furnace and air conditioner in the past. Even if combined into a single housing, these are actually two separate units instead of one. Geothermal, however, uses the refrigeration unit for both heating and cooling, reducing the number of expensive parts that can break. You can spec a single unit to do the job of two, reducing maintenance costs significantly down the road.

Conventional furnaces and air conditioning units need to be serviced at least annually in order to perform at maximum efficiency. Because conventional furnaces have a combustion chamber they have more high-stress parts to wear out than a geothermal heat pump. Conventional air conditioning systems use technology very similar to geothermal heat pumps, but because the heat-exchange coils are located in a harsh environment (outside in hot air) the compressor has to be much larger because it is under far higher load. Geothermal heat pumps, by contrast, are very simple and all components are safely tucked away in controlled environments. The only annual servicing typically needed is replacing the air filter.

Conventional furnaces have a life span of 10 to 15 years. Air conditioning units have a life span of about the same length. Geothermal units, by contrast, are very simple. Because they use the earth's energy rather than combustion they have less work to do, so they have fewer moving parts, are less stressed, and suffer less wear and tear than conventional systems.

Geothermal systems have a life span of 30 years or more.¹⁰ But there's even better news: your payback on the cost of a geothermal installation is typically less than six years, and as little as two. ¹¹ In well designed installations in appropriate applications your client could see a two to six year payback with a 30 year life expectancy!

Your clients might want to know that folks who have installed geothermal heat pumps are very satisfied with them. According to Manitoba Hydro, 91% of respondents to a survey of buyers of geothermal heat pumps were satisfied with their decision to install the system. 83% were satisfied with the energy savings achieved. And a full 93% were satisfied with the comfort of their home.¹²

Geothermal heat pumps provide not only a more stable temperature with far less energy consumption, but more consistent and more moderate humidity too, which translates into a greater perception of environmental comfort. As an added benefit, geothermal heat pumps are quieter because of fewer moving parts, lower load on the compressor and less cycle time due to the stability of the energy source. Quiet is that element of comfort we often don't think about because we don't notice it. The most comfortable system is the one you never notice because temperature and humidity are rock-solid consistent; the lack of noise is an added bonus that makes the system all but forgotten.