The rolling mountains of northeastern Pennsylvania make a beautiful setting for a home. The area is deep green in the summer, ablaze with color in the fall, and covered in a thick blanket of snow in the winter. The four seasons climate, however, means comfort challenges, and the owners of this home desired the ultimate in comfort, indoor air quality (IAQ), and efficient system operation. To get that, they entrusted the mechanical systems work at their new home to Quality Home Comfort Award winner T.E. Spall & Son, Inc.

“Most mechanical contractors do a good job of basic design and installation. But this home isn't suited to a ‘cookbook’ type of formula,” says John Dziedzina, the owner of this beautiful 8,291 sq.ft. home. “Tom Spall approached this job the way an engineer would. His system design really impressed me, and his crews did a very professional job on the installation.”

Dziedzina, who had been involved with energy audit work in the 1970s, was aware of his options when he selected T.E. Spall & Son.

“We knew we wanted a geothermal system because of the comfort, quiet operation, and energy efficiency geothermal offers. We also knew that in order for the system to work the way it should and provide the energy savings that it should, it would have to be designed right,” Dziedzina says. “Engineering expertise is critical for a complex system like this, with seven zones, combination hot air and radiant flooring, and a back-up boiler system. We knew of the contractor's ability to provide good engineering design.”

Thomas E. Spall, president of T.E., Spall & Son, was happy to provide the expertise.

“This project took four-plus years from its conception, design, installation, and final completion,” Spall says. “We were part of the design team from the start. The customer was an Energy Saving Service Plan customer of ours, and from positive experiences with us, named us as the proprietary HVAC company to the job.

“The homeowner stressed the importance of comfort, indoor air quality, and efficiency. That's why he decided on geothermal. He accepted nearly all of the design recommendations that we presented to him — not all upfront, but by completion, most were accepted,” Spall adds.

Architecture and aesthetics were of major importance on this project. The homeowner did not want to see or hear the home's mechanical systems. Spall calculated net free area requirements, and had woodworkers build custom supply and return grilles to blend in with the custom woodwork. In many areas the returns were built into the custom-made furniture units. Because of the use of the home for entertaining on occasions the homeowner asked that each of the second floor bedroom suites be zoned for use as needed.

The basement area required ductwork, piping and related wiring in an area where space was at a premium. After performing Manual J 8th edition load calculations and Manual D duct sizing calculations, Spall custom designed the duct systems and piping to meet design air and water flows, and verified the performance with system balancing and testing upon completion of the project.

Three Ground Loop Systems

The landscaping requirements led to the decision to use vertical geothermal earth loops. The loop design was performed with WaterFurnace loop and pressure drop design software. Spall's team installed three independent ground loop systems serving six geothermal heat pumps, with each having its own flow center to the earth loop.

“Transitional weather seasons, the spring and fall, can find a home in the Northeast needing heating in the morning and cooling in the afternoon, and we had a concern about possibly overheating the radiant spaces due to the fact it had ductwork as well as floor warming,” Spall says. “To overcome this, we chose to use tekmar temperature controllers to control floor temperature and also take outdoor air temperature into consideration and utilize warm weather shutdown.

“We embedded a piece of 3/8-in. copper into the mortar bed below the tile. This was accessible from the basement and allowed us to insert the sensor into the tubing and accurately sense floor temperature. The controller will not allow the floor to warm when the outdoor air temperature is above 72F. When the outdoor air temperature is below 72F, the controller will maintain the floor temperature of approximately 84F,” Spall explains.

The homeowner wanted an emergency backup generator system. This posed two major issues with our system: the requirements to run the compressors increased the size of the generator dramatically, and the requirements for the electric resistance supplemental/emergency heat also did the same.