Wednesday, May 16, 2018

A Conservation and Comfort Conversion in St. Johnsbury, VT

The house is a two story 4,800 (total) square foot log structure built by its owners several decades ago. The roof is supported by scissor trusses, which creates vaulted ceilings and a small attic space above the ceilings. Originally, there were two boilers providing the heat, a Frank's Wood Boiler and separate oil boiler, both tied into baseboard hot water heat. Both boilers were replaced and substantial building envelope improvements were made.  The owners chose to dramatically reduce fossil fuel heat while at the same time improving their comfort and saftey as much as possible. This post describes the process and results.

The project started with a call to Ed Whitaker at Green Thermal Systems  Ed smartly advised an energy audit before any heating upgrades began.  An energy audit that was coordinated through Efficiency Vermont After the energy audit was performed by Adam Barrett, New England Foam and Coating was hired to insulate the attic and box sills. 

Box sills were spray foamed. Removing fiberglass insulation from the attic was the next step. Thinking about air quality, the owners were keen to remove fiberglass batting that was compromised and soiled from 25 years of mouse intrusion.  After removing the fiberglass, truss bays were vacuumed and foam was then sprayed to a depth of 2-3" on top of the ceiling, along the bottom chord of the scissor trusses. Using spray foam in the roof served three purposes. The foam not only added insulation itself, but also provided a vapor barrier for the 13" insulation that was blown in on top of the foam. The foam also provided an air barrier, which dramatically reduced the chimney effect within the home. Chimney effect describes warm air escaping from the top of a home while at the same time pulling cold air in through cracks lower in the home. Just as a boiler sends hot exhaust up a chimney while cooler combustion air enters the boiler combustion chamber, a house can lose loads of heat due to chimney effect. Chimney effect also can pull gobs of unwanted cold air into a home, making rooms feel cold and drafty.

Foam Sill Insulation

New Spray Foam in box sill

Interestingly, there was another counterintuitive alteration of the building envelope. The home had an unheated, airlocked entry space inside the main door on the bottom level. Because this space was cold and located inside the rectangular footprint of the home, cold air was exposed to the home through two extra walls and a ceiling. Rather than trying to add more insulation and air sealing in the existing interior walls, the exterior door was replaced and the airlock was removed so that the entire heated space was exposed to a single, exterior wall. Doing so reduced leak points as well as the square area of exposed walls.

Along with improvements to the building envelope, the heating system received major modernization upgrades with expert advice and control strategy planned by Ed Whitaker.  Paul Cornell of East Burke, VT did the acutal piping.  Under-floor radiant tubing was installed throughout most of the home. A primary goal was to provide low temperature heat distribution. Low temperature distribution allows greater utilization of most heat sources, in this case, water to air heat pumps, a wood boiler, and a condensing propane boiler. Three out of four heating zones were converted to radiant floor heat. Radiant tubing was stapled under the subfloor. Aluminum heat transfer plates were attached to the tubing and the subfloor. Foil faced bubble wrap was placed 2" below the tubing, then a 3" layer of Rockwool, followed by a reflective plastic barrier.

Radiant floor cross section

Radiant tubing and installation (example)

Radiant Floor Heat Insulation InstalledView of Installed Radiant Floor Heat

Radiant tubing installed in joist bays

The home was already heated with a Solo Plus 60 wood boiler from Tarm Biomass

HS Tarm Solo Plus 60 

Solo Plus 60

To allow the wood boiler to operate more efficiently, three, 300 gallon, pressurized thermal storage tanks were added to the heating system. The three tanks were plumbed together, effectively creating a single 900 gallon thermal storage tank. By batch firing the Solo Plus, the boiler operates more efficiently and with lower emissions.

3X300 Thermal Storage

Three x 300 gallon heat storage tanks are located in the blue foam box.  The tanks are also wrapped in Rockwool.

The tanks also allowed the homeowners to produce heat with their new SpacePak water to air heat pumps during relatively warmer, off-peak hours.

Heat Pump Air to Water Compressors Rear View

Spacepak heatpump compressors

The heat pumps are only allowed to operate if the thermal storage drops below 130 degrees Fahrenheit (F). The radiant floor tubing provides adequate heat with 110 degree F water during the coldest periods.

Heat exchangers air to water heat pumps 

Heat exchangers from exterior heat pumps.  These are connected to the thermal storage, which then feeds the heating supply maniford.

Currently, the radiant floor zones are manually temperature controlled.

Heating Manifold

Heat distribution manifold with manual tempering valves

We encourage the owners to replace their manual tempering valves with active mixing valves, such as the Smart Comfort by LK Armatur These mixing valves and controls will set radiant floor temperature according to outdoor and room temperature.

110,120,130 SmartComfort

LK Smart Comfort mixing valve control

Excess heat made by the heat pumps is stored in the 900 gallons of water for use in the radiant floors after the sun sets and temperatures drop. Using their heat pumps in off peak hours makes it more likely that power being produced by the on-site 13.5 kW Solaflect photovoltaic arrays will be used directly on site, saves the homeowners money by not using power during high demand periods, and reduces pressure on the power grid when the grid is receiving its highest demand. From the standpoint of incentivizing heat pump use, using air to water heat pumps and thermal storage makes a lot of sense.

Solaflect PV Panels

Solaflect tracking photovoltaic panels

A backup condensing boiler was installed as well. The owner confided that at his age, he wanted to make sure that should he be stricken with illness or injury, he would have a conventional means for heating his home regardless of outdoor temperature. Maybe he'll be willing to consider a new Fröling pellet boiler to replace his wood boiler if that day comes.

Manifold and IBC LP Boiler

IBC Condensing propane boiler

Heating vital statistics:

10 Cords = Amount of wood burned per year with Solo Plus 60 before envelope upgrades

4.5 Cords = Amount of wood burned after envelope upgrades

2.5 Cords = Amount of wood burned after thermal storage and heat pumps are added in December 2017.

? = power production and consumption has not yet been tallied.

Stay tuned for more details about system performance.

Tuesday, May 8, 2018

Brian Millette, Steadfast for 29 1/2 Years, Retires from Tarm Biomass

Brian Millette is retiring!  Tomorrow, Wednesday May 9th, will be Brian’s last day at Tarm Biomass. 

Brian started working for Nichols Hardware in September of 1988.  I was still in high school at the time.  Brian was originally a floor clerk in the hardware store, which was owned by my Father Jim Nichols and Uncle Lloyd Nichols.  Possessing numerous talents learned from working on his own home, vehicles, and a wood working hobby, Brian was a perfect fit in a hardware store.  The store had a small engine shop and Brian even filled in making repairs to Husqvarna chainsaws.  By the time we closed the store in 2005, Brian played about every role, from checking in new stock to selling stoves and even helping install stoves and chimneys.  At that time Brian had little role at Tarm Biomass, which we picked up in 1994.  However, when the store closed and we focused only on boilers, there was no question to us that Brian would stay on our staff.  With his quick wit, affability, humble nature, and pride in a job well done, Brian has always made friends with customers and colleagues. 

Brian has suffered through the deaths of Jim and Lloyd Nichols.  He’s tolerated ownership transitions.  He’s worked through business transitions.  He’s taken hold of product line transitions.  He’s handled it all with aplomb.  His quiet assumption of the next duty has seemed as natural as taking a breath. 

For the past 13 years Brian has been the parts man for Tarm Biomass.  Many will know him for his soft, low voice and Northern New Hampshire accent.  What most will recall is Brian’s expert knowledge about spare parts and ability to get parts out the door ASAP.  One of Brian’s unsung traits is making sure that our customers get the parts they have paid for in perfect working order.  Our rate of parcels damaged in transit is almost zero.  There’s an authentic talent there rooted in taking pride in a job well done.

It is hard to know where to find guys like Brian, who show up on time regardless of the weather, regardless of how he feels, or for any other cause.  Heck, even his boss, yours truly, can’t match his on-time record.  When Brian’s been here to work, he works; that’s it. 

If you’ve done business with Brian over the last 29 1/2 years, please drop him a note and wish him well in retirement if the spirit moves you.  We’ll be in communication with Brian from time to time and will pass everything along. Don’t forget to wish us luck.  Brian is a hard act to follow.  

We count ourselves lucky to have been able to know and work with Brian for so long.

Monday, April 30, 2018

Last Day of Spring Sale 2018

Hello folks!  I saw 4 cars with snow on them while heading to work this morning.  Hopefully that’s the last day of frozen precipitation for the year.  We’ve had our share.  While there’s no guarantee with mother nature, we can assure you that today is the last day of our spring sale.  Take $2,500 off the price off residential sized P4 pellet boilers and $1,500 off Effecta wood boilers when purchased with thermal storage.  Call 800-782-9927.

Effecta_Screen_ImageEffecta_Two_tanksp4 pellet 15_schnitt_ab 2008-07

Tuesday, April 3, 2018

Great Technology is Only 1/2 of the Equation

Our local newspaper, the Valley News, recently ran an article about heat pumps titled, "Innovation, or Just Hot Air?". The article references a Vermont Public Service Department report, which found that in 77 studied heat pump installations, "the average annual energy cost savings was approximately $200.00 per heat pump, significantly less than had been assumed before the study."

Rapidly increasing sales of heat pumps have impacted wood and wood pellet boiler sales, so it would be easy for Tarm Biomass to pick a fight based on the Vermont study. Yeah, yeah. Not this time. It was clear to us long before the study was published that heat pumps are being over-sold. We've been waiting for the other shoe to drop for a couple years.

Rarely has there been an appliance that is so easy to sell as cold climate heat pumps. Heat pumps are like a magic box that heats and cools. Large savings are advertised. It's, "Hey, you can cut your heating bill in the winter and in the summer you'll have air conditioning that is almost like a central air conditioner." Installation is also relatively simple. We even have heard that heat pumps are renewable energy sources. Of course that isn't any more accurate than concluding that your refrigerator is a renewable energy source. That false attribute is so easy to twist into a sales presentation. Heat pumps are power consumers.

The problem with heat pumps isn't the technology itself. Heat pumps are brilliant technology. No, the problem is a multi-faceted human problem. Homeowners are hungry for inexpensive ways to save money and conserve energy, to do the right thing. The words "heat pump" just sound miraculous. The folks who are selling and installing heat pumps aren't doing so with energy conservation as the primary goal; or, if they are, they are failing. Energy incentive program managers are not carefully reviewing proposed installations to know that incentives are working toward their conservation goals. The well known truth is that heat pumps don't provide efficiency and conservation benefits in every application.

This problem with sales and installation in the energy world is not unique to heat pumps. We see it in the renewable wood heating world. We see it in the fossil fuel heating world. it is a BIG problem. Propane and natural gas boilers are sold with the promise of 90+% efficient operation, but that is impossible with most heating systems. Unless those boilers condense exhaust, efficiency remains in the low 80s. Oil boilers are almost always over-sized with many producing twice the necessary output, which leads to less efficient operation. Wood boilers are installed with pipes that are too small to send adequate heat to the heating manifold and they smolder instead of burning cleanly. We know a PV installer who tried to get someone to install 40 panels on a roof facing due west at 4/12 pitch. The power output reduction due to the orientation of the panels was around 25% right off the bat. The company that man worked for was huge at the time and later declared bankruptcy. The promise of clean, green, renewable energy can be a sham if it isn't backed by people with integrity who know their trade.

At Tarm Biomass we are committed to improving the reputation of wood burning. We don't advocate selling wood heat for every application. We spend a huge amount of time on educational materials and training. The boilers we sell self-monitor and are among the cleanest wood burning devices on the planet. As Bob Walker from Vital Communities so smartly said in reference to cold climate heat pumps and pellet boilers in his letter to the Valley News Forum, "These systems can help save money, increase home comfort, and reduce climate change impacts. Central to that is making sure you choose the most appropriate system and that it is professionally installed. "

Cheers, Bob!

Wednesday, February 28, 2018

Froling PE1 Pellet Boilers are EPA Approved, 30%+ Cleaner than Similar Boilers

Froling has received EPA approvals for PE1 20 and PE1 35 pellet boilers.  Results will soon be posted on the EPA Hydronic Heaters List, which can be found here:

The PE1 20 has an emission rate of .049 lbs/mmBtu/hr. and an annualized emission rate of .425 grams/hr.  Annualized efficiency is 78%.  The PE1 35 has an emission rate of .053 lbs/mmBtu/hr. and an annualized emission rate of .678 grams/hr.  Annualized efficiency is 80%.  Both boilers pass the stringent 2020 EPA emission threshold of .1 lbs/mmBtu/hr.

Very few pellet boilers on the EPA list have been tested using test methods required for meeting strict 2020 emission levels.  The Froling PE1 was tested without the use of thermal storage AND at the very difficult test operating range called Category I, which draws < 15% of the boiler’s rated output.  This means that the PE1 is not only legal for sale without thermal storage, but it also operates cleanly in very low load operating conditions.  With an added abillity to de-tune the boilers using the controls, clean outputs as low as 15,500 Btu/hr. are possible, which makes the PE1 20 a great choice for central heating in very efficient homes.

PE1 boilers still ship standard with intelligent storage tank management controls.  Though it is not required, Tarm Biomass encourages the use of thermal storage, especially when thermal storage can double as a domestic hot water source. 

PE1 boilers arrive with an internet connectable 7” touch screen.  Froling is in the process of rolling out a significantly improved and much more powerful version of its free “Connect” service, which will include not only historic monitoring capabiltiy, but a handy application for smart phones and tablets.  All boilers with touch screens, even those previously sold, will be adaptable to the new Connect sevice after a software update.  Stay tuned for more information about the new Connect. 


Friday, December 15, 2017

Advanced Wood Heating Can Flatten The Duck Curve

There is a pattern of power use and renewable power production that is putting pressure on electric utilities.  When power demand is highest- through the evening and overnight hours to morning- renewable electrical production is often at its lowest.  Power demand, when plotted over a 24 hour period can look like the silhouette of a duck. The graph below from the U.S. Office of Energy Efficiency and Renewable Energy illustrates power demand in California on a single day (March 31st) over several years. In the example it is possible to see the deeper "belly" and steeper "neck" that is caused by increased deployment of solar power and increased electrical demand in the evening. March 31st has a particularly steep "neck" because air conditioning is not greatly demanded during that season and solar power production is high. So, why does a steep duck neck put pressure on electric utilities? The utilities have a difficult time ramping up so steeply to meet evening demand. Further, during some days it is even possible to have too much power ("over-generation").

Scientists and planners often mention the need for electricity storage, better grid distribution of power, and altering consumer power consumption habits as means for "flattening" the duck.


The duck curve at this time is most impactful in California and Hawaii because of their high percentage of renewable power generation. Solar power contributed 40% of Californian power generation on March 31, 2017.

Forty percent of Vermont power is now also produced with renewables. What is interesting about Vermont and other New England States is that despite the known grid challenges created by renewable power generation and increasing nightly power consumption, state energy policies and the electric utilities that work with state incentive programs seem to be encouraging behavior that will only exacerbate the duck curve problem.

Consider cold climate air source heat pumps. Many tout these heat pumps as a renewable energy source, which of course they are not. They are basically highly efficient reverse refrigerators. Heat pumps can add heat in the winter and add cooling in the summer. Heat pumps are electric power consumers. The colder the air is outside our homes, the more power that air source heat pumps use. Also, what most people don't speak about is how much additional electrical demand will be created by air source heat pumps when those who previously had no air conditioning discover that a heat pump can also cool homes. Cold climate heat pumps promise to increase the duck curve whether in summer or winter. However, given reduced solar power production in winter the impact on the duck curve should be greater during cold months.

Advanced wood heat is a solution for the duck curve in the Northeast U.S. because wood heat is available any time of day. We tend to overlook the elegance of trees as solar storage. When burned in advanced wood boilers, decades of stored solar energy are released in a chemical conversion process that releases 80% or more of that stored energy into heat. By deploying advanced wood heat instead of heat pumps, States would not only flatten the duck's head, but reduce total power consumption and offset the use of other fossil fuels such as gas and oil.

Particularly in Vermont, which has been presented with a carbon tax plan called The ESSEX Plan (an Economy Strengthening Strategic Energy Exchange), the potential for exacerbating the duck curve has not been well addressed. The Essex Plan proposes to tax common fossil fuels such as gasoline, diesel, heating fuel, and propane and to use the tax income to lower electric rates, help with weatherization programs, encourage electric vehicles, and fund rebates through Green Mountain Power's Energy Assistance Program. Here is the problem: The ESSEX plan is completely electric power-centric. It seeks to encourage more heat pumps, more electric vehicles, and more conservation. These are reasonable goals, but why not encourage more biomass? Funds generated through the carbon tax should incentivize all forms of renewable energy.

It is amazing how much focus is put on renewable power and electric heat when advanced wood heat is being deployed now and helps solve several problems created by power-centric planning, such as the duck curve. Nature's solar battery is in ample supply. We know how to use it efficiently and in a way that supports not only the wealthy but also low income and rural populations. In fact, utilizing wood is an excellent tool for helping rural economics. Not only does wood harvest and processing produce jobs, but it increases land values and funds rural land owners through timbers sales. Let's not forget all of the benefits of advanced wood heat.

Thursday, July 27, 2017

Featured T4 Installation at the Marsh-Billings-Rockefeller National Historical Park

Boilers: Fröling T4 150 (500,000 Btu/r) wood pellet/wood chip boiler.
Previously installed Garn WH1500 (177,000 Btu/hr) with a water capacity of 1,420 gallons.
Thermal Storage: The Garn’s water capacity is used as the thermal buffer tank.
Fuel Storage: 20’ shipping container modified for fuel storage
Fuel Delivery: Modified P4 cyclone (day hopper) suction device.
Sold and Installed By: Sunwood Biomass of Waitsfield, VT | 802.583.9300 |
Location: Marsh-Billings-Rockefeller National Historical Park | 54 Elm Street | Woodstock, VT 05091 |

There is a mandate to invent an entirely new kind of park. It must be one where the human stories and the natural history are intertwined; where the relatively small acreage serves as an educational resource for the entire National Park Service and a seedbed for American environmental thought; and where the legacy of American conservation and its future enter into dialogue, generating a new environmental paradigm for our day. (John Elder, author and Middlebury College Professor Emeritus, From a speech at the opening of the Marsh-Billings-Rockefeller National Historical Park, June 5, 1998).

Tarm Biomass has had the privilege of providing two boilers for Marsh-Billings-Rockefeller National Historical Park, in Woodstock, VT. We applaud the National Park Service for its efforts to prove the value of an environmentally sustainable National Park System. This post is about the most recent installation of a Fröling T4 150 automatically fed and fired wood pellet boiler for heating a 30,000 square foot mansion at the park.

There are two boilers housed in the Mansion’s garage, which are used to heat approximately 30,000 sq. ft. The Garn wood boiler was installed a few years ago and reduced the Mansion’s oil consumption by about 50%. With the new Fröling T4 150 boiler installed, there is no fossil fuel consumed at the Mansion. Previously, the Mansion consumed 33% of the oil used at the park.

There were two unique challenges with the installation of the new T4 150. Both challenges were caused by a lack of space for bulk wood pellet storage and for a thermal buffer tank in the garage. Yet, the Park Service could not allow for the construction of additional buildings.

With the help of National Park Asset Management, LN Consulting, and the installing contractor, Sunwood Biomass, a plan was developed. A portable 20’ cargo container was chosen for the wood pellet fuel storage. The storage container ingeniously includes sloped floors, a Fröling suction screw auger system, fuel level sensors, fill connections, and all necessary safety devices. Because the Park Service also did not want the wood pellet fuel container visible during the busy summer season, the wood pellet fuel container is removed between early spring and late fall. To remove the wood pellet container easily, quick disconnects for both fuel and electrical were installed. Normally the Fröling T4 150 is not equipped for pneumatic delivery of wood pellets, but a hybrid fuel delivery system was created using portions of the fuel delivery system from a Fröling P4 pellet boiler. Pneumatic fuel conveyance through small, flexible hoses makes disconnecting the fuel lines a snap. The fuel storage container was even painted forest green and adorned with Park Service emblems.

During the summer, the Garn wood boiler is used for domestic hot water and any small heating needs.

The second challenge, including an adequate thermal buffer tank to improve boiler performance, was met by utilizing the built-in water storage of the Garn wood boiler. The Fröling T4 operates best with approximately 1000 gallons of buffer, so the 1,500 gallons in the existing system was a perfect solution.

There is one other Fröling boiler installed in the park. In 2013, a Fröling P4 32/38 wood pellet boiler was installed in the Double Cottage building, which includes two staff housing units. The P4 replaced an aging oil boiler and furnace. The building is now entirely free of fossil fuel.


The Marsh-Billings-Rockefeller Mansion


Alternate view of boiler house and pellet container

A view of the Mansion’s garage that houses the boilers and the pellet fuel container

Pellet container being moved

Pellet container being off-loaded

Combination of container images

Three views of the pellet container showing fill and building connections

Photo of inside of pellet container

Inside view of the pellet container

Full view of boiler house with door open showing boilers

Front View of garage housing the boilers

Front view of boiler and feed system, Garn in background

A closer view of the Fröling T4 Boiler

Close up of cyclone on feed auger

A close-up view of the pellet suction and day hopper

Tuesday, February 14, 2017

Hydronics for High-Efficiency Biomass Boilers Training

Update! The correct date and information for the upcoming NYSERDA boiler training. It seems our email subscription feed hiccuped and sent out an old post from 2015.


Friday, January 6, 2017

Featured Installation: South Main Apartments-Waterbury, VT

36 State Drive, Waterbury
The historic Ladd Hall in Waterbury, VT has gone through a huge makeover. The building was sitting vacant since August 2011, when Tropical Storm Irene hit and flooded the basement. The original  building was bult in the 1890’s with a wing added in the 1950’s to house nurses working at the state hospital. The building was then later used for offices for the state.

Building Information:

The original front brick building was converted into 2 3-bedroom apartments and a one bedroom apartment on the third floor. The 1950’s addition was totally demolished and replaced with new construction to house 23 more apartments (twelve1-bedroom and eleven 2-bedroom). The new wing is where the new heating system is located and is built to high energy efficient standards. The total square footage is 28,000 Sq. Ft. Building owned and operated by Downstreet Housing and Community Developement located in Barre, VT.

ladd-hall1  Architectural Rendering
                                   Waterbury South Main Apartments
                                                                                                   Completed View of New Construction Wing 
Heating System:  IMG_3071
The new heating system comprises of two 350,000 Btu/hr Fröling P4 pellet boilers with 900 gallons of heat storage. Heat storage allows allows efficient heating of Domestic Hot Water year-round and efficient boiler. The building has NO fossil fuel back-up boiler. The pellet boilers are estimated to offset approximately 10,000 gallons of heating oil annually. The boilers are connected to a 20 ton interior pellet store room. Each boiler has it’s own suction auger delivery device.
Heating System was designed by Trevor Parson, Engineering Services of Vermont, and Sunwood Biomass. Installed and manitained by SunWood Biomass, Waitsfield, VT. 802-583-9300

Viewing window for the pellet store room. The squeegee looking device is actually using a magnet to keep the glass free from dust.
Pellet fill connections.
We like the placards.
The original building.
The new wing housing 23 apartments of Affordable Housing.

Thursday, October 13, 2016

Announcing The Fröling Turbomat 500


The first Fröling Turbomat 500 (TM 500) has arrived in the USA! The TM 500 is a 1.7 mm Btu/hr. boiler capable of burning wood chips up to 45% moisture content or wood pellets. The boiler weighs over 18,000 pounds, in large part due to its heavily bricked firebox, which is necessary for wetter wood chips. The TM 500 uses a unique vertical heat exchanger that separates and drops out ash rather than allowing for ash to sit on horizontal heat exchanger surfaces. The TM 500 is designed to run 24 hours per day with no shutdowns for cleaning or re-fueling. The special alloy walking grate system needs no hoeing or scraping. The new TM 500 replaces another wood pellet boiler installed at Peoples Academy in 1982. The existing wood pellet boiler burned approximately 130 tons of wood pellets/year. The fuel feeding system is very simple for this installation. It consists of an exterior silo connected by flex auger to a surge bin above the boiler's feed auger.

The TM 500 will be replaced in the off shoulder seasons by a Fröling P4 100 pellet boiler when heat demand is lower. The P4 100 feeds itself by vacuum from the same silo that supplies the TM 500.

Both pellet boilers were sold and installed by Sunwood Biomass of Waitsfield, VT (802) 583-9300,

Below are some photos showing the assembly process.


The heat exchanger and the combustion chamber are joined together at the heat exchanger flange.


Neccessary components are installed before insulation and jacket assembly.


Insulation batts are installed.


Jacket frame assembled.


Boiler jacket panels installed.


Draft fan and stoker feed components assembled.


Flue gas recirculation, ash containers, door switches, air actuators, electical panel, etc installed.



Inside the combustion chamber (bottom). Here is good view of the moving grate and the fireclay bricks. Amazingly, all of this was asembled at the factory before it was shipped (approx. dimensions 3’x7’.


Combustion chamber (top).


The combustion chamber is almost large enough to lose someone.


Below, is a cross section view of the combustion chamber.

TM 500_Schnitt_2015-01-04 copy

A Fröling P4 80/100 boiler (350,000 Btu/hr) was also installed for use during the shoulder heating season. This TM 500 will be burning wood pellets. An intermediate surge bin (pellet hopper) was installed to bridge between the silo’s auger and the the boiler’s stoker fuel auger system.


The buffer tank and external fuel (wood pellets) silo.


Front view of Peoples Academy High School. The main building was built in 1928.


Which would you choose?