A geothermal heating and cooling system consists of two main components: the heat pump and the ground loop. While some people in the industry refer to the ground loop as the heat exchanger, many people simply refer to it as the loop or the loop field.

After a geothermal system has been installed for several months to a year, the grass from the drilling will have grown back a person could walk over the loop field and not even know that it exists. This is ironic considering how important of a part it plays in the geothermal system. It is the loop field that connects the geothermal heat pump to the ground and makes it the most efficient heating and cooling system available.

Many people often ask how deep the wells need to be dug for geothermal systems. The answer to this question is always, “It depends.” The reason it depends is because there are many different factors involved in the sizing of the geothermal loops, and many different designs as well. I have been to geothermal installations where the loops ranged from only six feet underground, to the 1,600 foot geothermal wells at the Peace Center in Philadelphia.

The real factor involved in how the geothermal wells are placed and the design that is chosen is driven by cost, the amount of space available, and the size needed to heat and cool a building. When there is a large amount of space available and cost is a consideration, horizontal geothermal loops may be chosen that range from six to twenty feet underground. Other than placing coils of loops in a body of water, this can be the most cost effective way to place geothermal loops. In the example of the Peace Center in Philadelphia, a large skyscraper needed to be supported by geothermal wells in a very limited space. This is where the 1,600 foot wells come in with a unique design known as standing water column.

With considerations regarding cost, the amount of space available, and the size of the system that is needed to heat and cool a building, a geothermal contractor or engineer will custom design a geothermal loop field. It is important to note that you should check to ensure that your geothermal contractor has been through a formal geothermal design or loop certification program such as IGSHPA (International Ground Source Heat Pump Association) or a certification offered through a geothermal manufacturer. For more information about the different geothermal loop designs available, feel free to refer to the Outdoor Portion section under Geothermal 101 on this site.

As seen on Geothermal Genius

It can easily be argued that the most important decision to make when purchasing a geothermal heating and cooling system is choosing the right contractor.  There is a phrase in the heating and air conditioning industry that the biggest factor in determining the efficiency of a heating and air conditioning system is the quality of the installation.  While there are several other factors that contribute towards efficiency, the quality of the installation definitely plays a large part.  When choosing the contractor to install your geothermal heating and cooling system, it is important to consider the level of detail in their proposal, the sizing of their proposed system, and their certifications and experience.

When selecting a geothermal contractor it is important to go through their proposal and sales process.  Be wary of contractors who use geothermal systems as a way to make other, less efficient, non-geothermal heating and cooling systems seem cheaper.  If a contractor offers geothermal but pushes you towards a high efficiency fossil fuel system, he may not have your best interests in mind.  Did the contractor go into the attic or crawlspace to inspect your ductwork?  Did they take the time to explain to you the effects that the drilling rig will have on your landscaping until the grass grows back?  While this is not always the case, many times the amount of effort that a contractor takes before a job will be a direct reflection of the care they take in actually performing the job.

In addition to ensuring they put time and effort into the proposal, you will also want to make sure that your geothermal contractor puts time and effort into providing you with the proper system sizing.  In order to properly size the geothermal equipment and loops, they have will have to perform a Heatload Calculation, also known as Manual J Calculation for a residence, in order to come up with the heating and cooling load needed for a home.  There are many different factors that go into this calculation such as the size of rooms, size of windows, orientation of the home, insulation values for the home, type and color of shingles, etc.  While some contractors may not perform a Heatload Calculation until a contract is signed or an upfront fee is paid, all quality contractors should perform this calculation before installing the equipment to ensure that the equipment and ground loop are properly sized.

Working with a geothermal contractor who has many years of experience and a driller who is familiar with the local terrain can give you a head start in feeling confident that you have chosen the right contractor.  To ensure they have a good reputation in the industry, look into their profile with the Better Business Bureau and check out online reviews for the company.  While asking for referrals or to speak with a company’s previous customer can be helpful, most often contractors will only provide you with a customer that they know will give them a rave review.  In addition to finding out how much experience a contractor has, you should also ask them about their certifications.  An important certification in the geothermal industry to look for is IGSHPA (International Ground Source Heat Pump) certification and an important certification in the over-all heating and air conditioning industry is NATE (North American Technician Excellence).

Choosing the right geothermal contractor can be a daunting task.  Do not let the fear or uncertainty stop you from making a great decision to purchase the most efficient heating and cooling system available.  Spend time with potential contractors going over the details of their proposals, ensure they are performing proper Heatload Calculations, and look into their experience and certifications.  Use this time to learn more about geothermal heating and cooling systems and choose the contractor that is right for you!

As seen on Geothermal Genius

A lot of people who are interested in geothermal heating systems for their home already have a heating system in place. While it is obviously easiest to install a geothermal system in a brand new house, there are many options available with geothermal retrofits to adapt your current system. Here are some of the common questions about geothermal retrofits that will help you decide if that option is right for your home.

Source: www.gagnongeothermal.com

Which type of heating system is the easiest to retrofit?

The easiest type of system to retrofit is a hydro-air heating system because its operation is not that different from that of a ground source heat pump. With a hydro-air heating system, a boiler heats air which is then distributed through the house via ductwork. If you replace the boiler with the geothermal heat pump for the primary heat source, the rest of the system only needs minimal adjustment. In some cases, the hydro-air system is left in place to serve as an auxiliary heat source.

Which type of heating systems are the most difficult/expensive to retrofit?

The most difficult systems to retrofit are older houses with baseboard heating and no central air conditioning. These systems have no ducts to distribute the air from the ground source heat pump, and you will need to have ducts installed for the new system. Radiant floor geothermal systems are very expensive, so it is not a recommended retrofit for residential homes.

Will the underground loops affect my landscaping?

Installing pipes underground will obviously involve digging up at least part of your yard, but horizontal loops only need trenches of about 6 inches wide. Vertical loops require even less space and will not cause very much damage to your lawn. In the long term, geothermal systems do not cause any problems with trees, grass, or other plants. After your grass recovers from the initial installation, you should notice no differences in your yard.

How much can I save with a geothermal system?

How much you will save replacing your current system with a geothermal system varies on how much you are currently spending on heating your house and how large a system you need to heat your home. There are many great tools available to help you, such as the Ball Park Investment Calculator, which will help you calculate how much a new system will cost and how long it will take to pay for itself. If you pay off your geothermal system over time instead of with a lump sum, the monthly cost will be less than your current fuel expenditure. Remember, geothermal heat is renewable!

What should I do to get my house ready for a geothermal retrofit?

Having a geothermal heat pump that has the capacity to both heat and cool your home is very important, and one of the things that factors into that calculation is how energy efficient your house is. You will want to make sure your house has enough insulation and ENERGY STAR rated windows and doors. Seal up any air leaks you find and you might even want to have a professional energy audit performed on your house. The more energy efficient your house, the smaller of a heat pump you will need, so it is an important first step before beginning the retrofitting process.

No matter what system you currently have in place, a geothermal heating and cooling system is a great way to make your home more environmentally friendly. Be sure to talk to a professional HVAC contractor to find out if a geothermal retrofit is the right option for you.

This information is courtesy of RineAir Heating & Air Conditioning, a Cincinnati heating and air conditioning contractor. Please visit their blog to learn more about green heating and cooling.  It can also be found at Geothermal Genius

Fall is here, and sure to leave again soon. This winter is supposed to be as rough as last year, and it’s vital to maintain your equipment before they take all the wear and tear the winter offers. We service and repair all types of heating equipment, and are happy to provide the service of a more efficient unit.

Get in touch with Green Air today for an efficiency check up, or service & repair on your Heat Pump, Boiler, or Furnace.

Richmond Illustrations

This is off topic for Green Air, but it was great to see some of these old block prints by Charles W. Smith on the Church Hill People News Website.  Click the link and check it out.

http://chpn.net/news/2011/07/06/the-block-prints-of-charles-w-smith_18468/