Water-source heat pumps help projects meet sustainability goals
WSHPs help projects meet goals.
As heat pump technology continues to improve, and as tax credits and utility rebates continue to provide incentives for water-source heat pump installations across the U.S., the popularity of this technology continues to grow. The following case studies show how three property owners have implemented this technology in order to save money and energy.
Home gets new Rx for efficiency
Morris Rill purchased this 7,383-square-foot contemporary home in Harrisburg, Pennslvania, from the late Alex Grass estate. Grass was the founder of the Rite-Aid Pharmacy chain headquartered in central Pennsylvania.
Grass built this home in the early 1970s, when oil was the dominant fuel for home heating. The previous system was a commercial boiler/chiller system using pneumatic controls. When Rill purchased the home, he knew he would need to upgrade the heating and cooling system for several reasons, the first being the cost to heat and cool the home averaged $6,000 per month for electricity and heating oil. The complexity of the pneumatic controls resulted in numerous service calls averaging about $700 per call, and the space required for the HVAC system, associated piping, ductwork, and controls in the basement were excessive.
Michael Armstrong, residential sales manager for Morrison Inc. in Duncannon, Pennsylvania, said the proposal was based on a thorough heat loss/gain done on the structure using the original blueprints and then calculating the needs of the customer to design and adapt the existing ducting to provide comfort zones meeting the family’s lifestyle.
“We proposed and installed a system comprising six closed-loop water-to-air Bosch Thermotechnology Corp. SM two-stage geothermal units feeding 11 different air zones,” Armstrong said. “In addition to the water-to-air systems, we proposed and installed a closed-loop Bosch TW036 two-stage water-to-water geothermal unit, which provides the home with all of its domestic hot water. The hot water system was coupled with a 120 gal. in-line storage tank to feed into the home’s existing recirculating domestic hot water piping. The total capacity of the geothermal system was 31 tons with 4,650 feet of closed-loop vertical bore and 9,300 feet of HDPE piping.”
All systems have electric, condensate, wiring, pumping/flow centers, and piping. All Bosch geothermal units have electric supplemental heat coils factory-installed. To save money on the installation, Rill removed the existing central system himself and scrapped the metals, thereby reducing costs of the installation.
“We were able to work in stages to allow a transition from the original system to the new geothermal system,” Armstrong said. “This allowed the family to stay in their home during the entire installation and removal process.”
After nearly a year of being in the home since the installation, the family is extremely happy with their decision to install the geothermal system. The home is now totally electric. Their highest single-month electric bill since the installation was $1,141 last winter — one of the region’s coldest on record.
“Mr. Rill keeps detailed usage records and said he cannot be happier,” Armstrong said. “The comfort level is fantastic, and he loves the fact that he can set the various areas of his home to the temperature that he wants. He is also happy knowing that by using Bosch equipment, he will have peace of mind due to the strong warranty and quality of the Bosch geothermal system.”
To ‘Enfinity’ and beyond
Aging equipment, improved occupant comfort, and energy savings catalyzed the decision to replace the HVAC equipment at this one-story office building in Birmingham, Alabama. Building owner Michael Jared of Jared Properties, a former Daikin Applied representative for more than 35 years, originally specified Daikin ceiling-concealed horizontal water-source heat pumps (WSHPs) when he oversaw the construction of Jared Square in 1985. So when it came time for replacement, Jared confidently selected 32 Daikin Enfinity WSHPs with MicroTech Integrated System controls for optimized performance.
“I had the opportunity to be one of the first users of the new MIS controls with the latest loop water manager,” Jared said. “This is absolutely cutting-edge technology for WSHPs and their control systems.”
The retrofit process was staged over a six-month period to avoid disruption to tenants that occupy 12 offices of various sizes.
“We replaced one unit at a time over a night or weekend,” Jared said. “The 32 ceiling-mounted WSHPs have all operated well.”
In late 2013, Jared Square implemented new Daikin Applied MIS controls technology concurrent with the installation of a new system panel and water-loop manager.
“The system manager consists of an industrial-grade laptop computer mounted in a panel that daisy-chains throughout the building to contact each MicroTech controller and compressor on each unit,” Jared said.
Prior to the controls integration, the units could only be controlled using analog functions. Combining them allows digital precision monitoring down to the unit level — in one building or many.
Jared has 24/7 access to the MIS control’s interface — whether on his desktop PC, iPhone, or iPad — so he can take immediate action on any issue. Small companies typically don’t get such a luxury.
“Jared Square is an excellent example of how you can apply large building controls to a light commercial building of smaller size for efficiency and accessibility, especially for retrofit applications,” said Chad Senger, controls product manager at Daikin Applied. “This is a type of control you only used to see applied to large buildings.”
Jared is particularly pleased with the Energy Efficiency Ratio of the Enfinity WSHPs and said the controls technology enhances an already productive system.
“The system gives you precise control for temperature and operating hours in occupied and unoccupied modes,” he said. “Our tenants appreciate that we can pre-program their in-ceiling units to their office hours and temperature needs. The system turns the loop pump on and off. In setback mode, the entire system shuts down automatically. All contribute to increased energy savings.
“Based on what we have seen so far, the new MIS controls package, combined with the new WSHPs, will result in substantial savings, perhaps in the 20% range over the original equipment. It’s an economical system that is energy-saving and does an awful lot.”
Strive for sustainability
Located in the heart of New York’s celebrated Finger Lakes wine region, Hunt Country Vineyards is a family-owned farm and winery. The 170-acre farm has been home to the Hunt family for six generations; today, the farm includes 50 acres of vineyards where the family grows 13 varieties of cool-climate grapes using sustainable agricultural practices.
In 2015, the New York Geothermal Energy Organization presented its Top Job award to Hunt Country Vineyards and Moravec Geothermal for the vineyard’s innovative geothermal heating and cooling system. Installed in 2012, the system supports the sustainability goals that are so important to the Hunt family.
“It’s all part of trying to optimize our environment for long-term sustainability,” vineyard founder Art Hunt said.
Prior to installing the geothermal system, the winery depended on a combination of propane, fuel oil, and electricity to provide heating and cooling for the wine-making operation. In 2011, Hunt approached Kevin Moravec, owner of Moravec Geothermal in Penn Yan, New York, with thoughts of installing a geothermal system at Hunt Country Vineyards, but it wasn’t until 2012 that all the pieces fell into place, including a $102,000 grant from New York State Energy Research and Development Authority (NYSERDA) that helped fund the system.
Critical to the success of the project was Phoenix Energy Supply in Auburn, New York, which provided piping materials, pumps, and valves. Under the direction of John Manning, president of the company, Phoenix Energy Supply helped with designing the system, laying out the loop field, and doing subassembly work while Moravec Geothermal coordinated the installation of the loop field and the GeoStar equipment that anchors the system.
The loop field is a 20-ton vertical closed loop comprised of eight 375-foot-deep bore holes and approximately 6,000 feet of piping. All this piping comes together in a single manifold that feeds into the tasting-room building. From there, it is distributed to two 4-ton and four 3-ton GeoStar Aston geothermal heat pumps and three GeoStar air handlers that provide heating and cooling to this building as well as the production building and the storage facility.
Moravec said the six GeoStar heat pumps are stacked in pairs, creating two stages of operation for each of the three buildings.
“We did this instead of installing three much larger units whose full load would not be required most of the time,” he said. “This design provides maximum conservation of energy. The more heat pumps that need heating or cooling, the faster the pumping system works.”
The system plays an important role in the fermentation process. Hunt said the winery harvests its red grapes late in the growing season to ensure maximum ripeness and the best red wines. That may mean leaving them on the vine until temperatures drop to 40° F.
“If you think about putting 10 tons of 40° grapes in a tank, that’s a huge thermal mass,” Hunt says. “They won’t ferment until the temperature in the tank rises above 60°, preferably in the 70°-80° range. So, we heat the grapes by running the warm glycol mixture supplied by heat pumps through jackets on the outside of the tanks. Once the temperature in the tank rises to 60°, the yeast begins to ferment, producing additional heat to warm the grapes.”
The tanks are heated a second time to warm wine that has been cold-stabilized to remove tartrate crystals and create a smoother wine.
“If you run ice-cold wine into a bottling line, you’ll get condensation on the outside of the bottle, and the labels won’t stick,” Hunt said. “So we pump the wine into a clean tank and warm it.”
In the case of Hunt Country Vineyards, the system saved the winery $10,000 to $12,500 in annual propane, fuel oil, and electricity costs while providing increased comfort in summer and winter for all the winery facilities.
Additionally, the winery recently installed 348 photovoltaic panels on the roofs of the winery, workshop and tasting room. Hunt estimates the solar panels will supply 70% to 75% of the winery’s electricity needs.
“Sure, it’s important that we take steps to save money and improve profits,” Hunt said. “But as we conserve energy with geothermal systems and solar panels and improve the land we farm, we’re really investing in our future — the seventh generation of Hunts already running around the property — so that one day they, too, can enjoy this land and the lifestyle it supports.”
This article was originally titled “WSHPs help projects meet goals” in the November 2016 print edition of Plumbing & Mechanical.