Written by Brad Crawford
Understanding geothermal heating and cooling is the key to deciding if it is the right option for you in your Dallas home. The first thing you need to know is that it is a renewable energy source. It still runs off electricity, but in a much more efficient way and the source of energy (heat) comes from the earth.
The layers of underground earth are typically between 54 and 67 degrees year round in north Texas. That temperature remains constant throughout the year because the ground actually absorbs nearly 50 percent of the sun’s energy. Geothermal heating and cooling taps into the energy stored underground and puts it to work for you in your home.
The first thing you need to consider is the impact geothermal has on the environment. A geothermal heating system has no emissions, so there are no greenhouse gases that harm the environment coming out of it. It consists of a heat pump, plastic or copper lines buried under the ground, and of course your heating ducts. As a matter of fact, it is actually a very quiet system that will allow you to sit back and enjoy the natural ambient noise around your Dallas home. You might actually enjoy hearing the wind blow or the leaves fall. Maybe even hearing squirrels chirping and playing in the trees.
The earth’s heat powers a geothermal unit, but that does not mean it is only good for heating. Geothermal is fully capable of cooling your home as well, just as much as your old system does. When it comes to cooling, the system’s flow is simply reversed to achieve the cooling effect. We will talk more about that in a moment.
The information that is probably at the top of your mind right now is the energy savings, or how much money will it save you and how long will it last? Well, let’s just give you a little perspective on it first. For every dollar that you spend powering geothermal, the unit returns $4 dollars’ worth of heat. Old HVAC systems are usually about 94 percent efficient, but a geothermal system is 400 percent efficient. So you can expect to see a minimum of 30 percent savings, but more realistically, closer to 80 percent energy cost savings – and it will last for many generations to come.
Just keep in mind that the cost of installing a geothermal heating and cooling system is higher than traditional HVAC systems, but it will pay for itself in just a few years. Also, you will qualify for a 30 percent federal tax credit, in addition to state incentives. But, don’t go trying to save money by installing geothermal yourself. In order for you to get the many years out of it you can expect, it needs to be installed correctly by a skilled professional that has experience in knowing where and how to lay the loop field. Otherwise, the system may not be able to harness the energy it was designed to produce.
Okay, now that we discussed the benefits of a geothermal system, let’s take a look at how it works. As we have already mentioned, the loop field, or heat exchanger, consists of several underground pipes that are either filled with water, antifreeze or a mix of both. These pipes are routed and buried through a system of underground loops, which absorb the heat. Depending on your location, the field can spread out horizontally or vertically. A skilled professional will have to make this call after he has taken everything else into consideration, including the blueprints of what is already down below the surface. The last thing he wants to do is hit a water pipe or a sewage line. Septic tanks can also heavily affect the layout of the loop field. But like we said, a skilled professional will know what to do in these situations.
Although you only need to go about five feet below the ground to reach the warmer geothermal temperatures, most contractors will go between 50 and 100 feet. In the case were there is an aquifer present, they will also make use of that as well, extracting the water then replacing it so nothing is consumed and everything is returned to the environment. But that is for a more complex, modified setup and we will stick to the basics here to help you understand.
Once the pipes are underground and the geothermal heat pump has been installed, as well as the air ducts, you are ready to fire up your system. During the winter when it is cold and you are trying to get the home comfortable, the water and antifreeze solution makes a constant loop through the field of pipes, pulling the cold air in your house with it, and returns back to your heat pump with a heated air temperature that has been absorbed and extracted from the ground. You might say that your home air is constantly traveling on a “comfortable temperature tour.” The heat pump then warms the air some more and circulates it throughout your home. This is where your energy bill kicks in, but the water in the loop field has done most of the heating so your heat pump does not have to work nearly as hard (you might even say 80 percent less).
But, when the summer months come along and it is time to cool the house, the geothermal system works in the same way, just in reverse. Basically, the hot outside temperatures will have heated your air enough so that when the air circulates into the loop field of pipes, the underground temperatures cool it down and loop it right back into your building. In most cases, 67 degrees is more than cool enough for the summer comfort.
To sum it all up, there is absolutely no down side to geothermal heating and cooling. It is better for the environment, better on your energy bill, it runs quietly, the government will give you a tax credit and the renewable energy source under your feet will never go away. With so many benefits and no repercussions, wouldn’t it be worth it to find out more?