LOADS

LOADS DATA for GLD

GLD integrates smoothly with a number of commercial and residential loads calculation programs that are available on the market. This section reviews:

• Commercial Loads Requirements
  
• Commercial Loads Program Integration
  
• LEED 8760 Hour Analysis
  
• Residential Loads Programs

Accurate Loads Data are Essential

Accurate load calculations are the foundation of a good geothermal heat exchanger design. Historically, engineers have been conservative in their loads analyses and have oversized loads. With traditional HVAC equipment oversizing is not particularly expensive. With geothermal systems however, oversizing is prohibitively expensive because ground loops are costly. Consequently, it is well worth the effort to calculate an accurate loads profile that takes internal gains and building diversity into account.

Commercial Loads Requirements

At a minimum, peak hourly loads (kBtu/Hr or kW) and annual loads (total kBtu or total kWh) are required for accurate design work with GLD. This is because as heat is rejected to and withdrawn from the soil, the soil temperature changes. Modeling this temperature change accurately is essential to designing a stable geothermal heat exchanger. Energy/annual loads calculations may be unfamiliar to commercial designers new to the geothermal field. Read this pdf to learn more:

• General Loads Information

Commercial Loads Program Integration

Below please find information about common loads programs that provide the peak and energy loads data that GLD requires.

• Trane Trace 700/System Analyzer (Interfacing Trane Simulations with GLD)
  • Hourly Data in Trane Trace
    
• GLD Carrier HAP  (Interfacing HAP Simulations with GLD)
  
• GLD IES <Virtual Environment> (IES Website)
  • Video Demo of IES working with GLD

GLD IES Ltd. is a European-based software company that develops the <Virtual Environment>, a leading European building modeling analysis tool.

LEED Certification and Loads Data

Hour by hour analysis is essential for calculating points for LEED (Leadership in Energy and Environmental Design) certification. GLD can model the system hour by hour for any vertical loopfield design to determine hourly loopfield temperatures and energy usage. Below is a sample hourly energy usage analysis calculated with GLD:

Designers may also use 8760 hour data from other loads programs. Any program that can export a file such as .csv, .xls or .txt file can supply data to GLD.   

Residential Loads Programs

Residential designs require peak hourly (kbtu/hr or kw/hr.) and energy/annual loads (total kbtu or total kw). In GLD, this energy/annual load is formatted as a run time fraction. Most residential load programs output peak data while very few output energy/annual load totals. LEAD PLUS, a program that calculates peak and energy loads, integrates effortlessly with GLD. For more information on LEAD PLUS and GLD Residential version, click here.