Geothermal Designs Arise as a Stormproof Resource

Advocates for geothermal energy say that the path of destruction cut by Hurricane Sandy, which unearthed fuel tanks, ravaged cooling towers and battered air-conditioners, has already persuaded some building owners to switch to geothermal systems that use underground pipes to harness the earth’s energy for heating and cooling buildings.

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The long-awaited Pinellas County Safety Complex goes geothermal!
Thanks to the efforts of Lend Lease, Engineering Matrix, and EggGeothermal, the $81 million project will be lean and green. Drilling is underway for the 2600 gallon per minute geothermal project. READ MORE

DOE Hot and Humid Report: Egg Geothermal Contributor and a Sponsor

It has been widely recognized that the energy saving benefits of GSHP systems are best realized in the northern and central regions where heating needs are dominant or both heating and cooling loads are comparable. For hot and humid climate such as in the states of FL, LA, TX, southern AL, MS, GA, NC and SC, buildings have much larger cooling needs than heating needs. The Hybrid GSHP (HGSHP) systems therefore have been developed and installed in some locations of those states, which use additional heat sinks (such as cooling tower, domestic water heating systems) to reject excess heat. Despite the development of HGSHP the comprehensive analysis of their benefits and barriers for wide application has been limited and often yields non-conclusive results. More

The"Renewable Energy Portfolio Standard - Renewable Energy Credits -Geothermal Heating and Cooling" bill (SB 652 and HB 1186)is the first of its kind in the United States.

TheMaryland RPS stipulates that electricity suppliers (all utilities andcompetitive retail suppliers) use renewable energy sources to generate aminimum portion of their retail sales, to a level of 20% by 2022. Electricitysuppliers demonstrate compliance with the standard by accumulatingRECs.

Amongmany industry and agency stakeholders, the Geothermal Exchange Organization(GEO)—that national trade association for the GHP industry—lentsupport and written testimony that were crucial to the success of the measure.

MarylandEnergy Administration Geothermal Program Manager Doug Hinrichs noted severalreasons for including GHP's in the Maryland RPS

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When Sussex County was faced with a failing geothermal system in their 4 year old emergency operations center (EOC) last June, it didn’t take long for the finger pointing to start. Steve Hudson, Sussex County’s director of engineering didn’t panic or finger point.

“I knew that we had to get the problem fixed, and there was no time for the blame game.” Hudson and his trusted #2, David Wootten went right to work looking for answers.

The geothermal cooling system was suffering incoming water temperatures approaching 100F. They knew that if the temperature hit 105F, the entire operation, and millions of dollars of computer equipment would be in jeopardy. The county commissioners approved an emergency budget to get a cooling tower put in. What about the geothermal system? A cooling tower would make the geothermal system a high maintenance, water consuming HVAC system.

Hudson and Wootten didn’t like it, so they looked a little further, and found there might be a better way. The Sussex geothermal design was like thousands before it: a series of wells are drilled into the earth, in this case 600 feet deep. Twin polyethylene pipes connected at the bottom by a ‘U’ bend that are inserted deep into the hole, and the hole is backfilled or pumped full of a cement type of material called ‘Grout’ that hardens and seals the hole, providing a good bond between the earth and the pipe. In total, there were 24 holes to provide for a 110 ton cooling load.

The problem is the Sussex EOC, like so many other commercial buildings, needs cooling 24 hrs a day, 7 days a week…even when the temperature outside is below freezing. So the heat from the building is pumped into the ground continuously for 4 years until: you guessed it, the ground could take no more. Steve found that this was not an isolated case.

They talked with one of the authors of the McGraw-Hill book, Geothermal HVAC, Green Heating and Cooling by Brian Howard Clark and Jay Egg. Jay Egg explained that this type of problem has been going on for some time. He began experiencing this is the early 90’s in the hot and humid climates of tropical Florida. Jay explained that in cooling dominant loads such as the EOC, the earth suffers thermal retention, and is unable to recover. However, there is a better way.

Properly engineered, geothermal systems can use a method called pump and injection. In this method ground water is pumped through an exchanger and injected back into the aquifer from which it was pumped. An aquifer is a body of water underground. The characteristics of aquifers vary widely. However, they are perfect for heat exchange.

At this point, Hudson’s team knew that they had found the answer. Now Hudson had the task of convincing the county commission that they could keep their geothermal system, but that they needed to spend money to properly engineer it. Steve said to Egg at one point, “I don’t know; It’s going to be a monumental task to convince our commissioners that we should spend a quarter million dollars and put in a geothermal system to fix our geothermal system.”

Hat’s off to you Mr. Hudson…6 months later, he pulled it off! Fast forward to Friday the 13 of January, 10am. In the conference room at the Sussex County EOC, there are 8 individuals in attendance. Among those in attendance are Hudson, Wootten, Sussex County Engineer Michael Izzo and Egg, and handful of county commissioners and employees, and David Hoffman of Gipe Engineering. David Hoffman’s firm has designed more than 600 geothermal systems for everything from homes to high schools. But he’s not too sure what to make of Jay Egg yet. Two hours later, Egg and Hoffman are like long lost family, enjoying lunch and some good stories about the early days of geothermal.

“It’s time we start engineering these systems right!” says Hoffman to Egg. There is no argument from Egg.

“The fact is, a properly engineered pump and injection geothermal system will cost one third that of a closed loop system; it will use almost no space, and the performance will improve.”, says Egg.

So why is the industry still doing closed loop? Well, we’re not quite sure. If you ask Hoffman now, he thinks the days of closed loop geothermal systems are numbered. “These guys have gone from $1500 a hole to $3000 a hole. I hope they’ve been saving their money, because they’re not getting any more of mine.”

Jay Egg has been going around the country listening to stories of woe from people who have abandoned expensive geothermal loop fields because they have “worn out”. Balderdash.

Joe Potter of Lend Lease, one of the world’s largest integrated project management firms is right there with Egg and Hoffman. “I think this is the way of the future, and the future is right now.” says Potter.

Lend Lease supported Egg’s first book. “We’ve been sustainable since before people knew what sustainable meant”, Potter said. “To us, this is just business as usual”.

Lend Lease’s Washington DC office is moving toward the EggGeothermal way of designing geothermal now. “This design will save the schools and taxpayers millions of dollars. I’m glad to see this improvement in system design” said Potter.

Hoffman and Egg are not stopping here. They have taken notice of a new advance in geothermal design. Geofinity, winner of the prestigious Building Automation Award from AHRI for 2012, is squarely in their sights as a preferred geothermal equipment line. The Geofinity product line now features a new controls platform called the ORB. The reason the ORB is so important has to do with the way it addresses the challenges within the geothermal HVAC industry.

Put simply, the ORB modulates and optimizes energy consumption within the components of the HVAC system the way a good hybrid vehicle controller operates the systems within the vehicle. Additionally, the ORB self diagnoses any issues that may surface before they become a problem. Finally, the ORB comes out of the box ready to communicate with your home computer, your iPod, or your smart phone; complete with full controls and diagnostics at your fingertips.

The Geofinity heating and cooling system will always be properly installed. Anything less will be noted by the ORB controller for immediate correction.

In larger applications, the iWorX commercial control system by Taco Electronics is the answer. The iWorX controllers can do for an entire building full of heating and cooling equipment, pumps, valves and controllers what the ORB does for your individual applications.

Whether you have an Emergency Operations Center like Sussex County, a summer home, or a good old American high school filled with 2000+ kids, geothermal is the way to go.

Tampa Bay — When a large mansion was under construction here seven years ago, the local paper announced that it was being built for Oprah Winfrey. It was an easy mistake to make, given the home’s trendy location. The street is famous for its many celebrity homes. Stephen King lives just a few doors down.

“All it takes is a rumor for misinformation to catch fire,” said the owner, chuckling. His fortune doesn’t stem from hosting a talk show. Rather, his background is in engineering, and so it was that his professional interests spurred him to pursue the most comprehensive controls systems available for his vacation home.

The home sprawls across 30,000 square feet, most of which are heated and cooled. A 70,000-gallon indoor swimming pool is located near the center of the mansion. Although the roof over the pool is all glass, with a bridge crossing the middle, there’s more to the arrangement than meets the eye.

The pool serves as a giant heat sink and source for the home’s extensive geothermal system. Through load sharing and geothermal technology, the carbon footprint of the gargantuan residence is dramatically reduced. Integrating the entire environmental system is Taco’s new iWorx controls system.

Out with the (not-so) old

Originally constructed seven years ago, the mansion’s HVAC needs were met by 13 four- and five-ton air-source heat pumps. It wasn’t long before the units had deteriorated noticeably, with oozing rust and decreased operational efficiency.

“It’s not uncommon for air-to-air systems to fail in four or five years around here,” said Jay Egg, president of Egg Geothermal Inc. in Tampa. “The salty air just tears apart outdoor equipment.” The owner of the mansion contacted Egg after talking with neighbors who had their systems replaced.

With 16 technicians at the original Tampa location, Egg Geothermal has been doing ground loop installations for the past 20 years. Recently, locations have opened in California and Georgia, managed by Jay’s brothers. The company designs and installs state-of-the-art systems. “We prefer to stick to commercial and high-end residential projects,” said Egg, “Of the 50 systems we installed last year, only a handful were installed in standard homes. For this large project, the homeowner came to us, not only looking for a more efficient system, but also for a system that wouldn’t deteriorate in the harsh atmosphere.”

Seven years into a 10-year warranty on his existing equipment, the homeowner was even willing to sacrifice three years of warranty to replace the aging equipment with new systems.

“’Just tear ‘em out and give me the best of what you’ve got,’” was pretty much what the owner said, added Egg.

Btu swimming free

“The homeowner stipulated that he wanted the new system to revolve around a load sharing concept, knowing that his swimming pool could be used,” continued Egg. “After all, he was right – a lot of Btus can swim in 70,000 gallons of water.

“In fact, it’s a fully-accessible, 400,000-Btu heat sink, right in the middle of the house,” he added. “The biggest challenge for us would be tying the ClimateMaster geothermal heat pumps together with the swimming pool, and the ground loop. We knew it had the potential of being a controls nightmare.”

Following the replacement of air-to-air heat pumps with geothermal gear, the house now has a total of 50 tons of heating and cooling capacity, a load shared by the swimming pool and well field. Each of the 17 geo­thermal heat pumps is on the closed condenser loop. The system is prioritized to take advantage of the heat source, or sink, that seasonally optimizes energy efficiency, regardless of user demand.

The well field is an open loop, vertical well system. It has one well for supply, and another for return. The South Florida climate isn’t well-suited for the use of closed loop systems due to thermal retention in the ground surrounding the wells.

“The owner, being a techie himself, wanted to have full control of the system,” said Egg. “He wanted to have the convenience of controlling the system in the Tampa vacation home while he was away, and he also wanted to see minute-to-minute energy usage and related data.”

It’s rare, admitted Egg, that homeowners seek that level of insight or to have full control of such a large, complex system.

Highly recommended

“iWorx was brought up on several occasions during conversations I had with some other industry professionals, and they told me to give the system a try,” said Egg. “As it turns out, and because of its incredible flexibility – with modules that easily expand or limit its use, full scalability and wide open protocols – the iWorx control platform was a slam dunk for use at the big home.”

Taco’s new iWorx system is a web-based building management, monitoring and control system. Designed for the light commercial market and hi-end residential markets, it serves buildings up to 50,000 square feet.

“What makes iWorx different from other systems,” explained Tom Polansky, technical service engineer at Taco, “is that you don’t need special tools, software or computers to do the installation or commissioning.” Once wired, programs are resident in the controller. By manipulating control parameters for the specific HVAC equipment on the LCI (Local Control Interface), engineering time is eliminated, and installation costs drop significantly.

System details at a glance

There are four pool heat pumps that provide about 400,000 Btu in heating capacity. They’re designed and prioritized to operate in a load match configuration with the cooling load of the home. Additionally, there’s a 900,000-Btu titanium plate-and-frame heat exchanger that provides passive cooling for many of the geothermal heat pumps. As Btus are fed into the pool to keep it warm, the end result is that 70°F to 72°F water is used as the first source of cooling for the geo units. Only if additional cooling is needed – typically in extreme summer conditions – are the open loop-supplied, geoexchange fluids circulated and tapped.

“We needed to use a titanium heat exchanger for the load-sharing,” said Egg. “The chlorine in the pool water is brutal punishment for even the best stainless steel units. We spent twice as much on a titanium system, but will never need to worry about it again.”

The geo units are scattered throughout the sprawling floor plan, ranging from 24 to 64 MBH in size. Some are outside; others are tucked away in closets. A VPU2 iWorx module controls the VFD-driven differential circulators for the closed loop portion of the geothermal system.

The well loop is powered by a submersible, 150-gpm pump as well as an external pump supplying the heat exchanger with pool water, both operated with VFDs. “In fact, all circulators and pumps at the home are driven by VFD’s,” added Egg. “The iWorx system controls the VFDs for all heating and cooling functions. With the DXU3 iWorx module, the pumps can run at 10 or 20 percent when we only need a fraction of the flow, saving a lot on operating costs.”

Equipped with desuperheaters, eight of the geothermal heat pumps meet all domestic hot water needs within the mansion, though – just to be safe – four 80-gallon electric water heaters serve as backup heat sources.

With the iWorx touch screen LCI, the homeowner can control the system on-site. If he’s at home, or at another vacation property, he can alter the control parameters for his Tampa Bay mansion online.

It’s rare that a home this size has such a small carbon footprint. Typically, it’d Sasquatch-sized. But, with technology that’s readily available off the shelf, it’s able to fit in a much smaller shoe.