Geothermal HVAC System

Archaeologist monitoring trenching

In fall 2003 Stratford Hall received a Save America’s Treasures Grant from the National Park Service to upgrade the HVAC system for the Great House–a building that had suffered fluctuations of temperature and humidity for years. After several years of preliminary planning by climate control engineers, contractors and staff, a design for a geothermal system was completed. Archaeologists from Dovetail Cultural Resource Group staked out the well-drilling line across the South Lawn in January 2007 and tested the area for potential artifact disturbance. Finding very little that had not been previously disturbed during excavations in the 1930s, the archaeologists made appropriate recommendations to the Virginia Department of Historic Resources, which subsequently gave the approval to proceed with the well digging. Archaeologists returned to the site at various times during the drilling project in case significant artifacts were unearthed.

In March 2007 Toano Well and Pump Service drilled the twelve wells required for the climate control system. Contractors removed the old boiler and air handling machinery and began to install new equipment. The existing 1930’s ductwork of the Great House was, to everyone’s amazement, found satisfactory to work with the new system.

Testing the 1930s ductwork

Installation of the geothermal climate control equipment by Colonial Webb, under project engineer Curtis Wilsey, continued into April. The old hot water lines were replaced and laid in the trench serving the geothermal piping; the boilers were considered a necessary part of the system to provide supplementary and back-up heat if needed in winter and re-heat capability for humidity controls in summer.

In June 2007 the contractors began testing and fine-tuning the system as it began its work of cooling the Great House. All trenching lines were filled in. Colonial Webb staff conducted training of site staff regarding system operation while Mike Moran of Mid-Atlantic Controls provided instruction on the use of the system’s monitoring computer.

By September 2007 the geothermal HVAC system was complete. Ken McFarland, Director of Preservation while the project was underway, gratefully submitted the final report on a project that will impact Stratford Hall’s main historic building for years to come.