Among the many ways HVAC contractors find satisfaction is through the daily opportunities they have to enrich customers' lives through quality home comfort. Greg Miscally, project manager at Environmental Air Conditioning Services, Inc., Jacksonville, FL, company founder Howard Stalls, and the engineers at Indoor Environmental Solutions, Inc. are no exception. They have an overwhelming concern for the customer, and they won't let up until every project is perfect.

It's even more rewarding when the level of customer happiness they bring goes from an ordinary thank you, to an ecstatic, "you're the answer to my prayers" kind of happy.

The EAC and IES teams often work together, and the two entities made it happen again during the summer of 2010, when they participated in a major geothermal retrofit for a luxury home located in Northeast Florida.

The owner of this classic Florida-style home just wasn't convinced that the existing five-year-old geothermal system was providing adequate relief from the Florida heat. The housekeeper provided another important piece of information: the system would trip off unexpectedly, well before the home was fully cooled.

EAC began servicing the home in 2007, and had discovered multiple problems with the existing system. After learning other engineers and contractors couldn't provide a solution, EAC consulted with the homeowner about having Indoor Environmental Solutions conduct an assessment and provide a design strategy.

Steven Griffin, P.E., president of forensic engineering firm, IES, was hired to determine why the home couldn't be adequately cooled, and to design a solution. Having worked with EAC in the past, Griffin enlisted them to help with testing.

They put on their detective hats and began their investigations. Among the signs discovered in the five-story home, was an increase in temperature of about 2F per floor. For a five-story home, that worked out to an approximate 10F difference between the ground floor and top floor.

"With geothermal systems, that's indicative of a high pressure fault," Miscally explains. IES found that temperatures in the water loops of the geothermal system were unusually high, suggesting that they were undersized.

"We ran our load calculations, and discovered that the air conditioning equipment also was undersized," Griffin says.

The existing vertical bore closed loop system consisted of 21 vertical wells, at 200- to 250-ft. deep,which was inadequate. All 12 of the home's air conditioning units became overstressed and damaged because of the extremely high summertime water temperatues of about 130F.

"The system wasn't rejecting enough heat for the air conditioning system to operate properly," Miscally says.

Following their investigation, IES took its data and went into design mode. They devised a solution that would keep as much of the original system in place as possible, to save the homeowner additional expense.

After much analysis and discussion, the team decided on a unique solution. They could make the existing geothermal closed loop system work in conjunction with an open loop and heat exchanger system.

"Occasionally, in cases like this, we can use a cooling tower to augment the heat rejection," Griffin says. "The homeowner's answer to that was an emphatic 'no.' So, that meant there was only one way to reject the heat: a plate-and-frame heat exchanger with a supply and recharge well (open loop) was added to the existing ground loops. You cut the pipes, put the heat exchanger in the condenser water line as it's exiting the ground on its way back up to the air conditioning units, and remove whatever heat the ground loops can’t."

Now, an open loop and closed loop system work together to cool and heat the home as originally intended. Miscally says the innovation has provided some excellent benefits.

"In summer, the open loop and closed loop wells work together. In winter, we don't have to burn energy running the pumps for the open loop wells, because the heat we pull out of the earth is adequate," he says. "We have great heating ability, and we save energy when the other wells aren't running. If anything ever happens with the existing closed loop system, where there is a rupture or piping is damaged, the open loop geothermal system is sized and designed to handle the full load of the home.

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"Redundancy has been designed into the system, including the heat rejection through the plate-and-frame heat exchanger, which can handle the total heat capacity. If there's any failure, we can open and close some valves, and get them going at 100%."

Overcoming Challenges
The large home had little surrounding property in which to drill the two wells, so they had to use the driveway and a section of landscaped property. EAC enlisted Partridge Well of Jacksonville to drill two, 600-ft. deep wells. The well heads were recessed in heavy-duty, marine-grade 4 ft. x 4 ft. vaults, to protect the motors, service valves, and disconnects located at the top of the well head.

Another challenge was time. EAC and IES committed to complete the project within 30 days.

"Originally it was slated to be a two-phase project, in which we would complete the water side of the system, and change out the air conditioning systems at a later date," Miscally explains. But, with the customer expecting a large number of visitors for the Fourth of July weekend, they proposed completing both phases before July 4th in an effort to go beyond customer expectations.

"It broke my heart to know they had lived in that home for five years, and still weren't able to be fully comfortable," he says. "I wanted the homeowner to enjoy the home. I knew we had the resources to get it done, and it required planning and preparation to put the right people in the right places."

Green Light
When you can't bring the home to EAC, you bring EAC to the home. To accomodate the short construction schedule, the 800 sq ft. garage was converted into a makeshift sheet metal shop and staging area. Then, the HVAC technicians, pipefitters, and sheet metal fabricators went to work.

In just 12 days, EAC installed 12 new Florida Heat Pump units, and a direct digital control (DDC) system by W.W.Gay Facility Automation of Jacksonville.

"With any project of this size, there are some small hurdles to overcome. It was a very large project, with many things to complete in a small window of time," says EAC President, Howard Stalls. "We worked Saturdays, Sundays, and 12-hour days to complete the project in that time period. We had to undo a lot of things that weren't correct, and alter the design of the system to a degree. Those were the big challenges."

"The Florida Heat Pumps are a practical, straightforward, simple approach," Miscally says. "We've had great success with them over the years. In addition, the DDC system allows us to monitor performance, to further adjust the system for maximum efficiency and performance."

The control system contains a laptop computer with various components programmed into it, to make all frequency drives, pumps, and valves function efficiently. Each system is built and programmed specifically for each job.

The home was commissioned by Steve Griffin and his team at Indoor Environmental Solutions, which was very crucial to the success of the project, Stalls says. The 12 heat pump units were activated in stages, all functions were tested, and the air and water requirements for the system were measured and analyzed by IES engineers.

Some minor airflow modifications and grille changeouts were made during system commissioning, to improve airflow through some of the rooms, along with a few tweaks to ductwork. The majority of the commissioning involved waterside troubleshooting and testing.

Final commissioning was in progress on the very day the homeowner arrived for the summer.

"It literally went right up to the last minute," Griffin says. "We were sweeping out the garage one last time as the homeowner drove up to the home."

Miscally says the greatest reward was in seeing the homeowner's reaction to constant reliable comfort.

"On the day the homeowner arrived for the summer, we had the house temperature at about 72F. It was great to see a smile on the homeowner's face, and to realize we had made the home cool and comfortable," he says.

The talent and cooperation of the EAC and IES teams were integral to getting the job done.

"The teams deserve a ton of the credit," says Miscally. "This is an elite group that gets things done right."

Steve Griffin says this project was yet another example of what he believes to be a major fault in residential comfort installations: lack of commissioning.

"The absolute number one thing we run into time after time is that jobs aren’t commissioned at all," Griffin says. "People don't pay attention to details, and a great system operates improperly.”

EAC and IES brought their full range of talents together, and worked in an extradordinarily cooperative fashion to make this a successful project.

And now, one more homeowner living in a challenging climate has the quality home comfort they've always wanted.

PRODUCT KEYS TO SUCCESS

  • 12 Florida Heat Pump geothermal package heat pumps
  • 2 Floridian Aquifer Wells at 600 ft depth. with marine-grade vaults
  • 2 Ultra Air Dehumidifiers
  • 2 Grundfoss submersible geothermal water pumps
  • Mastic sealed sheet metal snap lock duct externally wrapped with R-6 insulation
  • 1 Bell and Gossett plate-and-frame heat exchanger
  • 2 Bell and Gossett in-line water pumps
  • 4 Danfoss variable frequency drives for water pumps
  • Spirotherm air separator
  • Belimo water valves
  • Flow Design stainless steel auto-flo hose kits
  • Programmable logic control panel by WW Gay Facility Automation
  • Titus LL-2 linear grilles
  • Honeywell Vision Pro 8000 touch screen programmable thermostats
  • Aprilaire 2200 high-efficiency filters
  • CertainTeed Tough Gard duct liners