For ArchitectsPublished with the permission of the Director of Communications, GeoExchange.
Benefits to Architects
Today, architects are concerned with designing a building that is aesthetically pleasing to the senses, meet the owners needs, and facilitates the building's intended function. Integrating design components including shell, gazing, structure, and heating and cooling systems to gain synergies and economies is a major responsibility and opportunity for the architect as the key design professional.
GeoExchange can improve a building's form, function, aesthetics, efficiency, and comfort, adding to owner satisfaction. In addition, GeoExchange is ideal for the restoration of historical properties.
Form and Function
Form and function guide the design of each and every building. Form-the look and feel of a building's exterior and interior spaces-creates a first impression and an atmosphere that visitors unconsciously extend to the occupants of the building. GeoExchange can benefit a building's form by eliminating unsightly and noisy rooftop equipment, such as split systems and cooling towers. Without rooftop equipment, the architect has more freedom to experiment with alternative roof styles-adding flair to the building's form. Eliminating rooftop equipment also reduces the load-bearing requirements of the roof structure.
The use of GeoExchange systems may reduce construction costs in some buildings. Boiler rooms can be eliminated and the size of the mechanical rooms can be reduced. GeoExchange can reduce the size of air distribution ducts and reduce required plenum spaces. This can either allow higher ceilings or simply reduce construction costs.
Where form is the look and feel of a building, function relates to how well a building facilitates the activities for which it was designed. For example, as the design of a performing arts center must allow people to see and hear the performance arts center must allow people to see and hear the performance from every seat, the heating, ventilating, and air conditioning (HVAC) system must be able to handle wide fluctuations in sensible (temperature) and latent (humidity) cooling loads.
GeoExchange systems offer many advantages to architects. Less mechanical space means more productive space and more design freedom. For example, the extra space could be used to improve traffic flow or handicapped access, create well-planned reception areas, or allow more special-use areas.
The function of a building also dictates temperature control requirements of different spaces. GeoExchange inherently supports greater individual temperature control than competing HVAC systems because zones are relatively small.
Comfort
GeoExchange systems offer better occupant comfort than conventional systems by virtue of greater individual temperature control. Since they move heat rather than create it, GeoExchange systems are particularly beneficial in applications requiring cooling in some spaces and heating in others-applications that include most office buildings and other large commercial and institutional facilities.
Reliability/Maintenance
The elimination of outdoor or rooftop equipment improves reliability over conventional systems whose equipment is exposed to temperature extremes and dirt of the harsh out door environment. For this reason, less maintenance is required for GeoExchange systems. And they retain their high efficiency over the years.
Initial Cost
In cases where GeoExchange systems are initially more expensive, case studies how that those costs are quickly offset through energy and maintenance savings. In other cases, an integrated design approach shows that GeoExchange helps control initial cost.
Operating Cost
Low energy operating costs are one of the key benefits of GeoExchange. Numerous case studies document the energy savings of GeoExchange projects.
Flexibility and Unique Applications
The application of GeoExchange to, for example, combination convenience stores / gas stations demonstrates the flexibility of these systems. They integrate space heating, space cooling, and water heating with the convenience store refrigeration cases and ice maker. Many stations also tie in car wash water heating and ice melting to the GeoExchange system. Hybrid systems, combining the benefits of GeoExchange with other technologies, are increasingly being used in industrial applications, where they are particularly advantageous at integrating different heat sources and heat requirements within a facility.
Historic Preservation
Renovation of buildings with historical merit while preserving their architectural values is often challenging. They have a few, small closets, and finished surfaces (including ceiling heights) have intrinsic value and must be preserved. Because GeoExchange installations are so flexible, they are generally the easiest systems to design into an historic building. One successful strategy is to use smaller heat pumps dispersed in closets, basements, and attics to provide space conditioning and ventilation with minimal ducting. Of course, the ground heat exchanger is completely invisible, so there are no unsightly condensers on roofs or in back yards.
Natural Energy Efficiency
Energy efficiency is an important design component for any building. What better way to conserve natural resources than to use the earth as an energy source, and with geothermal systems the earth provides several times more energy than the electric utility
Continuing Education
Utility-sponsored seminars and workshops on geothermal heating and cooling are a great way to stay abreast of this fast-moving field. Also, contact the GHPC and IGSHPA for new geothermal seminar offerings.
Integrate GeoExchange Into the Design Process
To achieve the maximum benefit, geothermal must be integrated into the design process from the beginning. Bring in experts early in the collaborative process while the drawings are still on the board and specifications are being laid out. GHPC and IGSHPA can help you locate suitable experts in your area. The local electric utility can also provide information on available experts and can explain any geothermal rebates or incentive programs, which impact cost analysis.
Establish the preliminary design requirements of the HVAC system so that informed comparisons can be made between geothermal and conventional HVAC systems. Utilize experts to estimate the initial cost, energy performance, and operating/maintenance costs of geothermal versus conventional HVAC periods. Compute and analyze simple payback periods, life-cycle costs, and rates of return of the geothermal system and the competing conventional systems.
Present the results of the cost analyses to your client and obtain their approval to install the geothermal system. Establish the final specifications for the geothermal system by modeling the building with an hourly energy simulation program to determine precise design loads and annual heat transfer balances between the building and the ground loop.
Increasingly, thermal conductivity tests are being used to determine site-specific heat transfer characteristics of the proposed bore field. A test well is drilled, a sample loop installed, and the bore hole is grouted. The loop is then connected to a test set-up consisting of a heat source, temperature and flow sensors, and a data logger. In certain projects, results of thermal conductivity tests have allowed a 20% reduction of the ground loop and its associated cost, compared to designs based on U.S. Geological Survey data.
Indoor air quality is critical issue for today's buildings. Most states have adopted the building Officials and Code Administrators (BOCA) code for ventilation air requirements that mandate 15 cubic feet per minute of outside air for each building occupant. This ventilation requirement results in substantial HVAC energy penalties since much more outside air must be heated or cooled.
However, there are provisions in the code that can reduce these energy penalties. Pre-conditioning spaces prior to occupancy without drawing outside air and using the time lag at the end of the day are allowed by the code. In large spaces, the percentage of outside air drawn into a space can be controlled by CO2 Sensors. It is very important to establish the control scheme for indoor air quality as part of the final HVAC design specification.
Contacts:
Doug Rye, 3 Anthony Lane, Mavelvale, AR 72103, Phone: 501.455.2305
Ross Andrews, Phone: 706.935.6344, Fax: Same
Conceptual Estimates, 107 Greenvale Drive, Easley, SC 29640-7896, Phone: 864.850.9887, Fax: 864.855.7198, Email: lsherman@costanalysis.com
GEORGIA GEOTHERMAL ONLINE CONTROL
Back to - Industry Page
Made a Decision? Go to the Georgia Geothermal Commercial Loop Projects Page, or the Georgia Geothermal Residential Loop Projects Page for more information.
Copyright © 1998 Georgia Geothermal, LLC. Copyright © 1998 Geothermal Heat Pump Consortium, Inc.