Nelson Mechanical Design Martha's Vineyard Green Contractor
Copyright ©2005-2013
Nelson Mechanical Design
All rights reserved.

Nelson Mechanical Design is Martha's Vineyard's "green" mechanical contractor.

We started out in 2005 as a two man shop - after 10 years we have grown to a 9 person team.

To celebrate, we are having a summer long heat pump promotion - see below for more information.

We install, design, and service renewable and conventional heating, cooling, and plumbing systems.

NMD's new website will be uploaded soon! Below is our current contact info:


Nelson Mechanical Design (NMD) has a new phone system! After dialing 508 696 3120, please use the following extensions:

For Service Manager please press 1 to reach Colin Ouderkirke. His email is
Colin handles all service scheduling and invoicing at NMD.

For Bookkeeping please press 2 to reach Clara Matherly. Her email is
Clara handles all bookkeeping and financial statements at NMD

For New Construction please press 3 to reach Dave Sprague. His email is
David handles all new construction projects at NMD

For New Construction Project Coordination please press 4 to reach Noelle Nelson. Her email is
Noelle handles the coordination of new construction projects at NMD

For Human Resources and Marketing please press 5 to reach Sandy Webster. Her email is

For Financial and Accounting at NMD please press 6 to reach Jen Adamson, Chief Financial Executive at NMD.
Her email is

For Service invoice and statement queries, please press 7 to leave a message for our accounts receivable department.
The direct email is

For Brian Nelson, please send him email at

Our mailing address is NMD, Inc., 8 North Line Road, Suite B, Edgartown, MA 02539

NMD celebrates 10 years of service to Martha's Vineyard

Nelson Mechanical Design (NMD) was started in 2005 by David Sprague and Brian Nelson with a vision to offer the Vineyard a comprehensive menu of cutting edge "green" technology including geothermal, solar hot water, heat pumps, and hybrid heating and cooling systems; conventional fossil fuel powered heating and cooling; and residential and commercial plumbing and gas piping. Over the past 10 years NMD has grown to fulfill this vision - from the original team of David and Brian to our current staff of twelve techs in the field:
Matt Rivers, Keon Derrick, Brian Nelson, Mariah BenDavid, Dan Jenkins, Nate Kohler, Michael "Ollie" Olivera, Mike Mercadante, David Sprague, Noelle Nelson, Tom Neadow, Nick Rivers, Paul Vertiefuelle (kneeling) and service manager Colin. Office is Jen Adamson, Clara Matherly, Sandy Webster

NMD recent project - chilled water cooling system retrofit - June 2015

Nelson Mechanical Design (NMD) recently completed the first stage of the retrofit of a chilled water cooling system in a elegant residence in Oak Bluffs. The retrofit resolved air conditioning performance issues and reliability concerns while reducing operating costs. This was done through a thorough analysis of the existing installation and a re-engineering of the air conditioning system as a whole. The end result was a system that offered better cooling while using less electricity to operate.

More details and pictures to follow shortly!


NMD's Brian Nelson will be one of the "FAB FIVE" at World's Largest Hvac Show - January 2014

Nelson Mechanical Design (NMD) is pleased to announce that Brian Nelson has been chosen to be one of the "FAB FIVE" speakers at the 2014 Mechanical Town Hall Forum at the AHR Show in New York City. The AHR show is the world's largest exhibition of heating, cooling, geothermal, solar, renewable, and refrigeration technology.




From the Mechanical Town Hall website:

"Join us for the second annual Mechanical Town Hall, featuring five of the best speakers in the industry. This Q&A session will lend itself to audience participation as each speaker will lend their stories, experiences and expertise to the room. These speakers have been together on numerous panels in the past and have a unique comfort sharing the spotlight and stories with each other, and to the audience. Don't miss this chance to learn from the best... seating is limited"

Brian will share the stage with four other industry veterans and discuss new technologies, renewable energy, social media, and how to operate a HVAC company in today's market.

For more information click here

NMD installs the new Daikin 8 Zone Multi Split heat pump - December 2013

Nelson Mechanical Design (NMD)
recently installed Daikin's latest heat pump offering: a single outside heat pump connected to up to 8 inside units. In this residential project in West Tisbury, NMD connected one outside unit to 5 indoor units. Previously, a system like this would need two outside units - now the same inside equipment can connect to one outdoor heat pump.















For more information visit the Daikin webpage on this new heat pump - please click here

Innovative heat exchanger projected to save Mansion House hotel $17,000 a year in DHW fuel bill - November 2013

Nelson Mechanical Design (NMD) recently commissioned a 2,000,000 Btu/hr plate and frame heat exchanger at the Mansion House Hotel in Vineyard Haven that will reduce their annual fuel oil bill by a projected $17,000. This innovative heat exchanger system will use waste heat from the inside building loop/geothermal system to preheat potable water before it is heated by the boiler for domestic hot water use.

For ten months of the year, water coming in from the town water supply at 55 F will be heated up to 95 F by this heat exchanger - using free heat from the air conditioning system. A sophisticated control system optimizes the speed of the circulator that pumps building loop/geothermal water through the heat exchanger to make sure that all available energy is used to preheat the potable water.

NMD using PEX for hot and cold water lines in plumbing systems - October 2013

Nelson Mechanical Design (NMD)
has been using Wirsbo PEX plastic water lines (made by Uponor) for hot, cold, and hot recirculation lines in residential plumbing systems. This expands our offerings beyond traditional copper water lines.

A big advantage of using the PEX approach is the ability to use "homeruns" from each fixture to a central manifold - this permits easy draining and isolation of any fixture for service or replacement without disrupting the rest of the residence.

PEX is also extremely forgiving and can easily survive freezing weather. This makes it a valuable alternative to copper in homes that will be used seasonally.

NMD integrates Daikin Altherma with existing radiant floors and gas boiler - August 2013

Nelson Mechanical Design (NMD)
recently installed another Daikin Altherma heat pump/hot water system in a Vineyard residence. This particular installation includes the Daikin domestic hot water tank and the motorized valve to connect the Altherma system to the existing propane boiler and radiant floor system.

In a fashion similar to our West Tisbury Altherma pilot project (see below), we developed a way to integrate the Altherma with the existing propane boiler so that operation of the heating system is automatic. The Altherma looks at the outside temperature and turns off when it gets really cold. Then the boiler is turned on and the radiant floors don't even know the difference.

Integrating the Altherma in this way reduces the initial cost of the system as we do not have to heat the house when its load is the largest - when the weather is very cold. This means that we can heat the house 95% of the time with just the one Altherma and use the boiler for the 5% of the heating season.

NMD adds well drilling and water treatment services - May 2013

Nelson Mechanical Design (NMD)
is pleased to announce the addition of water treatment and well drilling services to its broad range of plumbing, heating, air conditioning, and green renewable offerings by partnering with J.A. Serusa Water Well Company.

Serusa logo How will this affect you, as customers? All communication - telephone or email - will now come from Nelson Mechanical Design (NMD). You will be speaking to our office manager Megan Lizotte. To make the transition a smooth one, we'll be asking for your contact information to ensure that our records are correct. We look forward to continuing the expectations you have come to rely on with Jeffrey.

By adding water source and treatment capabilities, NMD can now offer complete coverage of a home or business; from drilling the well, to treating the water, to heating the water with fossil, solar, or geothermal sources, to providing water throughout a home with plumbing, and to heating and cooling a home using conventional and green approaches.

NMD picked by Daikin to launch their national ad campaign- March 2013

Nelson Mechanical Design (NMD)
has been selected by Daikin (the global leader in heat pumps and air conditioning equipment) to kick off their national ad campaign "Likin' Daikin".

Brian Dave Daikin VODDaikin makes the air source heat pumps that NMD installs - Daikin mini split ductless and ducted heat pumps are as efficient as geothermal heat pumps (both typically reduce annual heating and cooling bills by 50%) but at a much lower installation cost (the Daikin heat pumps use air not the ground as their heat source so there is no geothermal loop).

NMD was selected by Daikin to be the first contractor "Success Story" because of our leadership in the "green" world - promoting and installing heat pumps as energy efficient alternatives to fossil fuel - and our single-minded pursuit of the best equipment and approaches to heating and cooling.

See NMD on the Likin' Daikin website

Read NMD's 7 Secrets of Success from the Likin' Daikin site

View the full NMD Likin' Daikin ad

The Daikin ductless "mini-split" heat pump - February 2013

Nelson Mechanical Design (NMD)
has been installing the Daikin "mini-split" ductless heat pumps since 2004 but we have noticed that their popularity has greatly increased in the last several years. While the technology they use has been successfully used in Europe and Japan for the last decade, these heating and cooling machines are just beginning to take off here in the U.S.

First some explanation of the terminology - a "mini-split" is a heating and cooling system that is divided into an outside unit (typically called the "heat pump") and an inside unit (the fan coil that moves, heats, cools, and dries air in the room) - hence the "split".

It is "mini" because these units are available in room-sized increments - a single small mini-split can heat or cool a single room while a larger one can heat or cool an entire floor. Because these systems are smaller that the typical American whole-house AC systems, they are called "mini".

The "ductless" term refers to the configuration of the inside unit - it has a fan that moves room air over a coil but there is no duct work - the inside unit is mounted on the wall close to the ceiling. This means that each room can have one of these units resulting in amazing individualized control room by room.

The "heat pump" part refers to the idea of using refrigerant - in this case ozone-friendly R410 - to move heat either into the building in the winter or out of the building in the summer. Amazingly enough, in the winter the outside unit gets cold enough that it can pull heat out of the outside air (even down to 5F outside!) and use this energy to heat air to 110 F - resulting in very comfortable winter heating.

These units are so popular because they are extremely efficient (the same as geothermal - about half the cost of propane to run throughout the year) - which is why they are used in all of the "passive houses" and the most energy efficient buildings being constructed today - and very affordable - a system can be bought one room at a time making it very easy to expand to include other rooms in a home.

Daikin makes the air source heat pumps that NMD installs - they are very well made units that are highly efficient.


Innovative pool heating heat exchanger cuts fuel oil use at the Mansion House - January 2013

Nelson Mechanical Design (NMD)
installed an innovative heat exchanger at the Mansion House hotel in Vineyard Haven that is projected to reduce their fuel oil use by more than $13,000 gallons annually. This savings is developed by a plate and frame heat exchanger that takes waste heat (essentially solar energy that has heated up guest rooms) and uses it to heat the swimming pool. The result is that the fuel oil fired boilers will run much less, the pool will be heated indirectly by the sun, and the carbon footprint of the hotel will shrink dramatically.

West Tisbury geothermal / wind turbine project works seamlessly - December 2012

Nelson Mechanical Design (NMD)
completed the installation of the "Geo Balls" in a West Tisbury residence and commissioned the geothermal system they installed. This home will be the third "net-zero" residence in West Tisbury and the third completed by NMD - each of these houses features a wind turbine and a geothermal system. This project also features the innovative Honeywell indoor air quality ventilation control as well as the new Honeywell display thermostats.

Innovative "desuperheater" system reduces propane use - November 2012

Nelson Mechanical Design (NMD)
installed an innovative domestic hot water preheat system called a "desuperheater" that preheats water before it is heated by a propane fired boiler. This system uses that waste heat from geothermal heat pumps as the source of heat - essentially the solar energy removed from the residence's warm rooms by the heat pumps in their cooling mode.

Geothermal "rescue" prevents a system from failing due to aggressive water - October 2012

Nelson Mechanical Design (NMD)
successfully "rescued" a geothermal installation from aggressive water that was threatening to dissolve the heat pumps and piping from within. Over the past several years since the system was installed, the water has gotten more and more acidic and system pumps and pipes have started to fail. NMD installed a plate and frame heat pump to isolate the inside geothermal system from the aggressive water outside while permitting energy transfer.

Variable speed pumping retrofit of heating system cuts propane use - September 2012

Nelson Mechanical Design (NMD)
used a "smart" variable speed circulating pump to reduce the annual propane use of a large heating system. The existing system had constant circulation of hot water to four large air handlers (blower units with hot water coils connected to duct work). This meant that the propane fired boiler was running all the time to keep the constantly flowing water hot at all times. NMD replaced the existing constant circulation pumps with a new Grundfos Magna variable speed circulator and installed motorized zone valves on heating pipes going to each of the air handlers.

Viessmann propane boiler domestic hot water control upgrade - August 2012

Nelson Mechanical Design (NMD)
installed an innovative control system to "fool" a Viessmann propane boiler into turning off the domestic hot water function in the winter when the seasonal home was unoccupied. By "speaking" Viessmann, the new control system was able to shut down hot water production in the winter months and reduce the use of propane.

Solar hot water system with innovative "active" energy collection - July 2012

Nelson Mechanical Design (NMD)
installed an innovative solar hot water system at Brian Nelson's personal residence to test a brand new energy collection strategy - the use of motorized valves and four different storage tanks - each at a different temperature. The use of a cascading control scheme and constant flow circulation through the solar hot water collectors is aimed towards maximizing the solar energy collection throughout the year.

Daikin Altherma heat pump installed in Edgartown for a radiant system - June 2012

Nelson Mechanical Design (NMD)
installed the Vineyard's second Daikin Altherma air to water heat pump in Edgartown. This innovative unit uses the stored solar energy in the air to heat water in a "buffer" tank for use in a radiant floor heating system.

Safeguarding a control system from the Island's erratic power supply- May 2012

Nelson Mechanical Design (NMD)
constructed an override system for a large residence on the Vineyard to protect the geothermal heating and cooling system from the erratic power provided by the power lines - especially during storms.

Internet based control system for Vineyard estate with four homes- April 2012

Nelson Mechanical Design (NMD)
installed an internet based control system that linked four buildings on the property and assisted the caretaking staff in reducing propane use by 30%.

Daikin Altherma Air to Water Heat Pump Pilot Project in West Tisbury - March 2012

Ted Bayne and Lea Delacour
live on Martha's Vineyard in a 3,000 square foot home heated by radiant floors and a Viessmann propane boiler. Their goal was threefold – to find a heating source that would make their existing 90% efficient heating system more economical to run, would not involve destroying their extensive gardens with a geothermal installation, and would use electricity to operate – making their home ready for the “all-electric” island that Martha's Vineyard will become in the near future.

Until the arrival of the Daikin Altherma, there was no realistic or cost effective way to meet these goals. The Daikin Altherma provides geothermal levels of efficiency at a much reduced installation cost and can operate all winter long. They contacted Nelson Mechanical Design (NMD) to design, engineer, and install an innovative heating system that would meet their three goals. NMD recommended the Daikin Altherma as the solution that uses electricity, operates at geothermal efficiency levels of 200 to 400%, has a tiny outside footprint, and heats water for the home's radiant floors and domestic hot water system.

Read more, schematics, plans, etc. are here!
Contractor Mag's 2010 Contractor of the Year
Contractor of the Year Award

Nelson Mechanical Design, Inc. (NMD) was recently selected "2010 Contractor of the Year" in a national survey by the Penton Media Group, a publishing firm that serves 50,000 mechanical contractors across the United States.

Penton publishes CONTRACTOR Magazine, Green Mechanical Contractor, Radiant Living, and Heating, Plumbing, and Air Conditioning Engineering. This national award is recognition for NMD's work this year on several "green" mechanical projects across the Vineyard, according to a press release.

For the rest of this article in the December 2010 issue of Contractor Magazine please click here. More also here: "Tough Customers need to save energy, too"

Green Mechanical Contractor Cover article

NMD's work at the Mansion House is the cover story in the latest issue of Green Mechanical Contracting. Bob Mader, Editor-in-Chief, described NMD as "a perfect combination of technical know-how and a creative mindset.”

Nelson Mechanical Design’s work on the Mansion House – converting groundwater issues into “geothermal gold”, reducing the carbon footprint through advanced controls, and helping the hotel become the “greenest hotel in Massachusetts” is the focus of the Winter 2010 issue of Green Mechanical Contractor.

Full text of article is here.

David Sprague and Brian Nelson
E-mail Brian Nelson E-mail David E-mail Colin