1. January / February 2017
10 SPECIAL REPORT
I
n 2010, the multinational con-
sultancy and engineering com-
pany Amec Foster Wheeler
faced a critical design challenge
with one of its American clients,
the National Park Service (NPS).
The NPS is an agency of the
US government that manages
all of the country’s national parks,
national monuments and other
conservation and historical
properties.
One of its most recognised
historical venues, the Longfellow
House in Cambridge, Massachu-
setts, was suffering from a failed
geothermal system and costing
the agency exorbitant amounts
to operate auxiliary heating and
cooling systems.
GEO SYSTEMS
There was much at stake for both
the NPS and Amec. The venue
is an all-wood structure of mid-
Georgian architecture, which
houses priceless historical docu-
ments and artefacts, all of which
depend on precise, dependable
humidity- and climate-control
systems for preservation.
The original geothermal system
designed to provide and sustain
these critical functions was an
open or ‘pump and dump’ type
system. Because open systems
circulate groundwater directly
through the heat pump, they can
be very efficient, allowing direct
access to the groundwater’s
thermal energy. Unfortunately
for the Longfellow house,
however, its groundwater con-
tained high concentrations of iron
and manganese that fouled the
pumps and pipes feeding the
system – a common problem for
open systems in that area.
The open style was originally
selected because there wasn’t
enough available space on the
grounds to install a closed-loop,
U-bend system. Closed systems
are made of polyethylene plastic,
which is impervious to harsh
groundwater, but require more
wellbores and land space to
compensate for the material’s
poor heat transfer characteristics.
For a geo system to feasibly exist
on this site, the Amec consultants
needed a new technology.
NEW DESIGN
Senior Amec project manager and
engineer John Peterson led the
design and geo implementation
for the Longfellow site. He had
learned of a new composite-based
closed-loop system, which had
only been commercially available
for a few years.
Rygan Corporation, a material
sciences company from Tulsa,
Oklahoma, had developed a
low thermal resistance fibreglass
composite system that had
been successfully used on other
projects. After representatives
from the two companies met,
Amec decided to conduct a
test utilising the new composite
system in one of the existing
open wellbores.
The performance Peterson
witnessed from the test bore
resulted in a new design for the
Longfellow house based entirely
on the Rygan composite system.
According to Peterson, the
Rygan technology provided
the NPS with a sustainable,
geo-based solution, which would
have otherwise been impossible
due to land space constraints and
archaeological restrictions.
“The site grounds presented
numerous constraints and archaeo-
logical barriers to drilling or land
disruption. A traditional polyethyl-
ene U-bend type system would
have required drilling and trench-
ing for 20 wellbores, which was
impossible for the site. The Rygan
system allowed us to provide
a high-performing yet closed
system, impervious to groundwa-
ter elements and with minimal
drilling and disruption,” he said.
Peterson also stated that the
performance they’ve seen on the
Longfellow house “isn’t achiev-
able with traditional systems,
open or closed”, and that the sys-
tem has enabled solutions they
Rethinking
geothermal
Rygan Corporation’s
ground-heat
exchange system
helps heat and cool a
historic US landmark
Pipework for the
Rygan system,
with the
nose piece at
bottom right
Left to right:
Rygan system
well heads
with laterals; the
Longfellow House;
cross-section
of Rygan HPGX
10-11_Rygan_GDI1701.indd 10 03/02/2017 09:33

2. 11
January / February 2017
FEATURE NAME 11SPECIAL REPORT
couldn’t have conceived of seven
years ago.
URBAN PROJECTS
Since the commissioning of the
Longfellow house in 2011, the use
of Rygan-based geo systems has
grown with government, commer-
cial and residential jobs across the
US, often in areas that could not
accommodate another geothermal
system due to space restrictions.
“Most of our projects happen in
urban and metropolitan settings,
says Rygan co-founder and chief
operating officer Lane Lawless.
“Our material with its coaxial
configuration greatly reduces
thermal resistance between the
formation and the heat pumps on
the surface. Because we’re more
efficiently and effectively exchang-
ing heat with the ground, we
usually need half or less of the
drilling and land space required
for traditional polyethylene
U-bend systems. This ultimately
means we can deliver geo-based
solutions to the more densely
populated urban areas that have
traditionally been ineligible for
geo due to space constrictions.”
When asked if Rygan has plans
to move beyond North America,
Lawless says the framework for
that is now in the works.
“We have several potential
projects we’re looking at in the UK
and Scandinavia. The key is having
a good indigenous partner who
will exert quality control over
design and installation. We’ve
been fortunate to work with
superb designers and installers in
the US, and now we believe we’ve
found that same quality of partner
in the UK. Regardless of your
technology, it takes quality-
minded people to deliver a quality
geo solution.”
Rygan Energy Solutions has been selected as the approved
partner for the UK market. It will deliver the Rygan technology as
a turnkey, mechanical solution, with a full design and installation
service. “We have our first commercial installation in the UK in
March this year,” says Lee Hormell, director of Rygan Energy
Solutions, “and have several projects in the pipeline. Due to the
success of Rygan-based systems in the US, a repeatable
template has already been established that we can utilise here.”
UK calling
The most efficient, proven
ground source system
available, which is being
widely installed on projects,
exceeding expectations
Turnkey design, consultancy and
installation service at the forefront of
providing the most advanced and efficient
ground source systems for projects ranging
from small to large scale commercial
Contact us for advice
and feasibility on your
next project
Tel: (01909) 724286
Mobile: 07540 635 766
e-mail: info@rygan.co.uk
www.rygan.co.uk
Below left:
installation of the
Rygan system
showing the
nose piece
10-11_Rygan_GDI1701.indd 11 03/02/2017 09:33