Save Precious Water With Geothermal Heating and Cooling

Geothermal-Sourced Chillers Save
Billions of Gallons of Fresh Water

Think about the types of building materials that have endured. For example, cement, concrete block, gypsum, and good old fashioned wood/lumber. These have all endured as building materials favored by many. Water has certainly endured as a medium for heating and cooling. Commercial buildings pump the lifeblood of cooling and heating systems through a building in the form of chilled or heated water, depending on the needs of the building. 

Geothermal heating and cooling (HVAC) completes this wonderful cycle by coupling buildings with the shallow Earth, just like a tree’s root system. Closed loop piping filled with life-giving water circulates, transferring the heat to and from the Earth, similar to the way tree roots transfer the essentials of life from the Earth through their branches and leaves. This is perfect symbiotic sharing of energy with the Earth, and is as close to nature as one can get in the process of heating and cooling of building.

Like a Tree's Root System, Geothermal Couples a
Building with the Shallow Earth to Transfer Energy

With respect to refrigerants, water is called "R–718". It has impressive thermal properties, and can be engineered through the established fluid flow practices to efficiently transfer heat to and from a building, using far less energy than forced air systems, and significantly less energy than is needed for refrigerant flow based systems. I mentioned refrigerant flow, because there seems to be a fad of sorts involving equipment with multiple evaporators in homes and commercial buildings. Whether these variable refrigerant systems with multiple evaporators are geothermal sourced or not, the fact remains that pumping refrigerant through building uses more energy, is not natural, and you might wonder what the long-term effects are, as well as the energy efficiency aspects.

Fact is that recent studies prove unequivocally that refrigerant flow takes more energy per BTU than just pumping water. Commonly use refrigerants (other than R-718, water) must be pumped at high velocity to keep the compressor oil en-trained within the stream running through the refrigerant piping. This high velocity pumping wastes significant power when compared with hydronic (water based) heating and cooling systems.

Greg Cunniff, co writer of the book, "Modern Geothermal HVAC Engineering and Control Applications McGraw-Hill 2013”, has done significant research on the subject, some of which can be seen in results from comparisons at the headquarters of ASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers) in Atlanta.

Water seems limitless, especially when looking at the oceans, which cover about 2/3 of the planet.  Fresh water is not as abundant.  Most of it is in our aquifers, and it’s important that we conserve this resource. Used for drinking water is OK, but using water for things like cooling a building might be a little reckless. 

Commercial buildings, hotels, airports, factories, schools, shopping centers, high rises and power plants use cooling towers to cool down their air-conditioning, refrigeration, and process loads in their facilities. Cooling towers use evaporative cooling principles to decrease equipment size and increase energy efficiency.

Cooling Tower Consumption of Fresh Water is
Eliminated By Geothermal-Exchange

These commercial facilities have a many needs for fresh water that include sanitary, irrigation, and cooling tower.  According to the EPA, about 25% of the water used in office buildings is for the cooling load.  In process cooling applications like laboratories and manufacturing, the consumption for cooling towers is more than 50% of the total consumption of fresh water.

To put this into terms of gallons of water, a typical 50,000 square foot high school will use about 30,000 gallons of water per day; enough to fill two basic swimming pools.   Indianapolis International Airport can use a million gallons of fresh water just for cooling on a summer day.

Geo Saves Fresh Water and Increase Longevity and Resiliency

The US had between 71 and 81 Billion square feet of commercial space in 2010, served by 2 to 3 billion tons of cooling capacity.   [based on floor space estimates from DOE report] This represents between 1 Billion and 3 Billion gallons of fresh water consumption each day.

In our efforts to conserve Earth’s water resources, geothermal sourced heating and cooling will save billions of gallons of fresh water. Some locations can use surface water, others will use ground coupled exchangers, and many will use aquifer thermal exchange

Summary:

Hydronic (water-based) geothermal heating and cooling systems are the most energy efficient HVAC systems in the world today. Less is more; simple is better.

More information on Geo? Just use #GeoDay2015 for social media, and checkout the Geothermal Day Website , IGSHPA and the Geothermal Exchange Organization. 

Jay Egg is a geothermal consultant, writer, and the owner of EggGeothermal. He has co-authored two textbooks on geothermal HVAC systems published by McGraw-Hill Professional. He can be reached at jayegg.geo@gmail.com .

Geothermal HVAC Project Implementation; A Primer

Ready to do that Geothermal Heating and Cooling Project?

Assemble Your Geothermal Team From Local Professionals

Implementation of geothermal sourced cooling and heating systems can reduce energy consumption up to 40% compared with other high efficiency HVAC technologies. But first, a good geothermal team needs to be assembled. A geothermal team consists of all the parts to make a geothermal heating and cooling project come to fruition; and they’re likely right in your locale.  You may want to install a geothermal system in your office building, or have it deigned for a whole community, and the parts will be much the same.  Like a library full of books, the knowledge is there.  What makes knowledge powerful is when it is assimilated for a great purpose like earth coupled HVAC.

IGSHPA Baltimore 2014 Proves Singularly Successful

1990's IGSHPA Plaque

From the workshops and committees to the involvement of major manufacturers and suppliers, it's apparent that a new day has dawned for the geothermal HVAC industry. Multi-billion dollar companies have invested in the GSHP market, stirring remarkable progress. 

Dr. Bahman Habibzadeh, Emerging Technology Manager for Building Technologies at the DOE's office of Energy Efficiency and Renewable Energy (EERE) was on hand as Richard Soper, President of Bosch Thermotechnology (Bosch TT) stated that the GSHP industry is going mainstream in the US and that the current roster of IGSHPA Certified Installers will need to increase to between 30,000 and 40,000 to accommodate demand in the industry. With current membership, we are looking at 10-fold growth in the near term.

Dr. Liu from ORNL & Jay Egg

The presence of the US Department of Energy proved enlightening as Holiday Ballroom 4  at the Baltimore Hilton was filled with attendees listening and participating as the DOE's Building Technologies Office (BTO) reported the successful outcomes of  American Reinvestment Act projects.  All were enriched as Dr Xiaobing Liu from Oak Ridge National Laboratory (ORNL) reported insights, and Dr. Yong Tao shared results from DOE funded GSHP studies and projects. 

IGSHPA Baltimore Keynote Breakfast, October 15, 2014

I for one feel fortunate that I was present to see history in the making at IGSHPA, Baltimore.