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Pond-based Geothermal

pond_residential_color

An Intro to Pond-based Geothermal Systems

There is a vast quantity of free, clean, and renewable energy in our ponds, oceans, and the waters that surround the Vineyard. Through the use of geothermal heat pumps, we can collect and concentrate this low grade stored solar energy into high grade energy to heat and cool our buildings. This energy is available 24 hours a day all year long.

Because the Sun is storing this energy for free, a geothermal heat pump can typically collect 2 to 4 units of free energy for every unit of energy put into the heat pump. The end result is an efficiency ranging from 300 to 500%! In comparison, boilers and furnaces are fast approaching their limit of efficiency (currently some of them have 98% efficiency) of 100%.

Because geothermal systems are 3 to 5 times more efficient than the best fossil fuel systems, their operating costs are about half. In other words, the annual cost for electricity to run a geothermal system is half the annual cost of propane or fuel oil to run a furnace or boiler.

We proposed our ocean based geothermal system in November 2006 and our pond based approach in September 2007. The following sections will have additional details about the ocean and pond approaches as well as an introduction to some ecological and permitting issues.

Pond-based Geothermal System

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32-ton Slim Jim Heat Exchanger

We wish to describe a geothermal system that will use the stored solar energy in a pond (or any sufficiently sized body of water) to heat and cool a building – we call this system “pond based geothermal”.

This system will consist of a plate type heat exchanger (SlimJim brand) submerged in a pond (held in a vertical position and mounted to a skid resting on the bottom), a geothermal heat pump and circulator pump located inside the structure, and supply and return pipes buried at a 4 foot depth connecting the heat exchanger in the Pond and the heat pump.

A First for The Vineyard:

We believe that there have been no geothermal installations on the Vineyard that have used ponds (or other bodies of water) for their source of stored solar energy. While this pond based geothermal will be the first use of this geothermal concept on the Vineyard, there are many successful installations of this type around the world.

In Chicago, the Coast Guard Marine Safety Station uses a SlimJim heat exchanger under their pier to provide all of their heating and cooling. Even in the middle of last February with two feet of ice on Lake Michigan, the Coast Guard station was warm and toasty with heating provided solely by the stored solar energy in the 37 F lake water.

The largest manufacturer of geothermal heat pumps in the world, WaterFurnace, heats and cools their entire factory from the stored solar energy in a man made pond in front of their headquarters in Indiana.

The Concept: Pond Based Geothermal:

The geothermal process uses energy from the Sun that is stored in the Earth, the oceans, or the bodies of water on the surface of the Earth. As we receive more energy in 10 seconds from the Sun than mankind uses in an entire day, this is an essentially limitless supply. The geothermal process connects this abundant yet low grade energy to a heat pump which is able to concentrate the energy and raise it in temperature to a more useable form. Through the use of a heat pump we will be able to use the solar energy stored in a pond to heat a building.
slimjimheatexchanger1

How Does This Geothermal Process Affect a Pond?

This geothermal concept will use a small fraction of the available solar energy stored in the pond’s water. Sizing software will allows us to project

the amount of solar energy available in this pond. The available energy is basically a function of the pond’s area and its volume of water.

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The amount of energy we wish to “remove” from the pond to heat a residence will be minute compared to the constant input of solar energy into the pond – our analysis indicates that for a properly sized installation, there will be no measurable effect on the pond’s temperature.

The Installation: Plate Type Heat Exchanger

The heat exchanger (herein called the SlimJim) is a stainless steel or titanium welded plate type device used to exchange heat between the pond water and a closed geothermal loop. The SlimJim is formed by welding and pressing two plates of stainless steel or titanium together – each assembly is pressure tested and fitted with inlet and outlet pipe connections. Nominal dimensions of a 5 ton capacity (60,000 Btu/hr) unit are 4’ in height, 8’ in length, and ½” thick with a weight of 100 pounds. This heat exchanger plate may then be suspended under a pier, suspended below a float, or mounted on skids for pond-bottom locations. There is an absolute barrier between the pond water and the closed geothermal loop – the system is designed to be leak free over its entire life expectancy of 50 years (or more).

A typical installation would involve placing the SlimJim in the deepest part of the pond – it is recommended that at least two feet of unfrozen pond water be above the SlimJim at all times.

The Installation: Geothermal Heat Pump

The geothermal heat pump will be located in a mechanical room and will be connected to the buildings heating and cooling system. The advantage of a geothermal system is that it replaces direct use of fossil fuels and has an efficiency on the order of 400% – for every unit of electricity put in the system outputs 4 units (because the sun has given us three units for free into the pond). This means that typical operating costs are up to 50% of a gas or oil system. Once a geothermal system is coupled with electricity generated by a renewable source, as wind or solar PV, the carbon footprint of the project shrinks to zero.

The Installation: Supply and Return Pipes

The pipes that connect the SlimJim to the heat pump with be black polyvinyl (HDPE) well water tubing of 2” in diameter. They will be buried at a 4 foot depth from the house to the SlimJim. The pipes can be installed with a trenching machine to reduce disturbance of foliage to a minimum.

*Covid-19 Policies*

Given the ever-increasing impact of COVID-19, we have worked hard to determine the best way to continue to serve our customers while keeping both them and our staff as safe and healthy as possible. For us this means practicing the guidelines set in place by the Boards of Selectmen and Health. This includes a ZERO-TOLERANCE policy requiring any employees who are, or…

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About Nelson Mechanical Design (NMD)

NMD is Martha’s Vineyard “green” mechanical contractor, designing and installing just about anything to do with heating, cooling, domestic hot water, water treatment, or controls: geothermal systems, heat pump systems, fossil fueled systems, air conditioning, solar hot thermal, plumbing, well water service, water treatment, ventilation, and internet accessible control systems. In the residential world, they designed and installed the mechanical systems for…

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About Your Equipment and System

About Your System: Each of these menu topics describe the components of  the various heating, cooling, ventilation, and plumbing systems that we install and service.  Our goal is to make this part of our website a resource to better inform our customers about their equipment and systems.  When you call for service, we hope the information will assist you in describing what…

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Air Conditioning 101

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Contact Us

If you are a new customer in need of service, click here to expedite the process by filling out our online service intake form. If you are building a new home or renovating your existing home, click here to expedite the process by filling out our online new construction intake form. Nelson Mechanical Design (NMD) has a new phone system! After dialing 508…

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Contractor HVAC Fillable Form

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Daikin Altherma Heat Pump Installation

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Emergency Services

Our emergency services are for our loyal customers of record.  If you are not a customer, please call us during our business hours to become one. Emergency contact: 508-696-3120 (24 HOURS A DAY OUTSIDE OF BUSINESS HOURS) Emergency hours:  after 4 pm Monday- Friday, anytime outside of business hours Saturday & Sunday Master Technician, $180.00 Technician, $165.00 Holiday hours: National Holidays (observed)…

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Equipment Installation Examples

These pages provide installation examples of the many different types of equipment we install in businesses and homes on the Vineyard.

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Featured System Installations

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Frequently Asked Questions

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Furnaces & Ductwork Installation, Service, and “Rescue”

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Geothermal – Radiant – Rescue Team

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Geothermal System Installation, Service, and “Rescue”

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Heat Pump & Mini-Split Installation, Service, and Rescue

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Heat Pumps (Mini-Split)

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Homeowner HVAC Fillable Form

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HVAC

This page will redirect to either ‘HVAC – Homeowner Team‘ or ‘HVAC – Contractor Team‘

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HVAC – Contractor Team

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HVAC – Homeowner Team

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Info Sheets

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Installation of Water Treatment Systems

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Installing a new plumbing or HVAC System?

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Interested in Mini-splits?

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Internet access to your home

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Island iron issues

Click on the image at left to scroll through some examples of iron issues commonly found on the Vineyard.

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Mini Split Team

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Mini Split Team Test

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Mini-split Case Study: One inside wall unit to one outside unit

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Need HVAC or Plumbing Service?

Are you in need of service on your HVAC system or plumbing?  Please fill out the form below and our service manager will contact you.  Thank you!

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Need HVAC Preventative Maintenance?

Have we installed a heating and cooling system (ducted or mini-split) at your home but haven’t provided you with preventative maintenance to keep it in top notch condition?

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Need Water Treatment Service ?

We offer extensive water treatment service options.  Please visit our water treatment pages on this site for more information. Thanks!

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New Construction Design Process – Heating, Cooling, and Ventilation

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NMD Showcase

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Plumbing Fillable Form

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Plumbing Team

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Preventative Maintenance

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Preventative Maintenance Flat Rate Pricing

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Privacy Policy

Nelson Mechanical Design, Inc. does not share client contact information or information about their properties.  We respect our client’s privacy and the security of their personal information and homes.

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Products

Our role is to install and service the most reliable and modern heating, cooling, ventilation, air quality, plumbing, and water treatment equipment available.  We serve as an essential filter for our customers – determining what innovations are worth pursuing and what new products we can stand behind.  This requires a constant commitment to training the NMD team so that we know how…

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Projects for Non Profits and NMD Concepts

We support the efforts to build affordable housing here on the Vineyard.  We have donated time and money to the various housing groups to aid their important work to create long term stability through affordable housing.  Some of our recent affordable housing installations are shown below. Over the years, we have developed some concepts that merit further investigation.  As we move towards…

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Resources

Frequently Asked Questions: The menu topics are representative of questions we have answered about the equipment and systems we install and service.   While the laws of physics haven’t changed lately, technology is evolving constantly, and our role at NMD is to understand how this evolution affects our systems and customers.  We are constantly learning about new techniques and approaches to HVAC…

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Service Fillable Form

Are you in need of service on your HVAC system or plumbing?  Please fill out the form below and our service manager, Marlon Dwyer, will contact you.  Thank you!

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Service Team

Our service team is ready to help our customers service their HVAC, plumbing, water treatment, ventilation, and control systems around the clock.  Our normal service hours are from 8 am to 4 pm.  After that we have on-call personnel to attend to our customers’ emergency needs.  If you have a need for service after our business hours, please call 508-696-3120 and follow…

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Services

Installation, Service, and “Rescue” We offer installation, service, and “rescue” for practically anything and everything involving heating, cooling, ventilation, indoor air quality, plumbing, water treatment, and internet access in your home or business.  We have installation teams that focus on new construction projects (new air conditioning, heat pumps, ducted furnaces, boilers, mini-splits, etc., etc.,),  we have service teams that are able to troubleshoot,…

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Solar Hot Water Installation, Service, and “Rescue”

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Terms & Conditions

Please review the following items about our billing process, payment, service teams, and other important aspects of NMD.  Once you accept these Terms and Conditions (by clicking Submit at the bottom), we will be able to assist you with your service needs or a new plumbing and HVAC project.  

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Test Page1

  Service team training Service team in action Brian Nelson in action! Service Team Adventures! Service team specialized tools Service team battles rodents!

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Thank you for your inquiry!

We appreciate your interest in our services and installations!  We look forward to working with you towards meeting your HVAC and plumbing needs.  Our goal is to respond quickly to your query – we try to respond via phone or email the same day for service queries and within a few days for new construction projects.   If you are inquiring about…

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The History of Water on Martha’s Vineyard

Living on Martha’s Vineyard comes with many wonders and struggles.  Water quality can be one of those struggles.  The water on the Vineyard varies tremendously based on the different layers of rock and sediment left by the receding ice sheet 10,000 years ago.  So levels of iron, manganese, and other minerals as well as acidic or basic water can vary dramatically from…

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Water Softener Systems (Brine Tanks)

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Water Treatment Installation and Service

We are starting our Water Treatment Promotion!  Learn more.… The History of Water on Martha’s Vineyard Living on Martha’s Vineyard comes with many wonders and struggles.  Water quality can be one of those struggles.  The water on the Vineyard varies tremendously based on the different layers of rock and sediment left by the receding ice sheet 10,000 years ago.  So levels of…

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Water Treatment Preventative Maintenance

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Water Treatment Promotion Page

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Water Treatment Systems for Acid Neutralization (Low pH)

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Water Treatment Systems for Iron Removal and Reduction

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Water Treatment Team

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What We Test for in your Water

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Who We Are

Check here for all that is new at Nelson Mechanical Design.  You will find our latest promotions, Constant Contact emails, articles about us that have appeared in local and national press, articles about our team members, and features on our innovations in the HVAC and plumbing fields.

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Why Choose NMD for your HVAC project with a contractor, builder, or architect?

When you call the HVAC-Contractor team at NMD for a quote on a new heating and air conditioning system for your new home or renovation project, the follow steps happen: Matt Rivers and David Sprague will arrange a site visit to your property or office to review the plans for the project and discuss and what the client needs are in terms of…

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Why Nelson Mechanical Design?

David Sprague and Brian Nelson started Nelson Mechanical Design in 2004 with a commitment to Martha’s Vineyard – we will provide the best service to our customers,  provide stable, long term careers to our people, and support the fabric of our island home.  

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