Finalists Announced for International Stove Competition

Finalists Announced for International Competition to Build Cleaner Wood Stove

Pool of inventors, universities and manufacturers will compete in first-ever Wood Stove Design Challenge

Judges announced today the 14 finalists for the Wood Stove Design Challenge, the first international competition to build an affordable, cleaner-burning wood stove for residential heating. The finalists' stoves will be tested and judged on the National Mall in Washington, D.C., in November 2013. The winner will receive $25,000 cash.

The Wood Stove Design Challenge was launched by the Alliance for Green Heat, an independent non-profit, to bring more innovation to a popular, widely used renewable energy device. In selecting finalists, judges looked for designs that could produce ultra-low emissions, high efficiency, in addition to innovation, affordability, and marketability.

[quote from Nathan Russel]

Among the 14 designs are stoves controlled by microprocessors and connected to smartphones, as well as ultra-efficient stoves based on 17th century Scandinavian designs and several state-of-the-art hybrid stoves that are already on the market. Six are from Europe.

Judges examining testing equipment last week at Brookhaven National Lab

The nine judges

met last week at DOE's

Brookhaven National Laboratory and include leading experts fromPopular Mechanics, the New York State Energy and Research Development Authority (NYSERDA), the US Forest Service, Washington State Department of Ecology, DOE BrookhavenNational Laboratory, The Biomass Thermal Energy Council, the Osprey Foundation, the Masonry Heater Association and UC Berkeley.

The EPA requires most new wood stoves to be far cleaner than the unregulated stoves of the 1970s and 80s, which were notoriously polluting. Even so, the wood stove has not been embraced as a clean energy technology by most policy makers or the public, in part because low emissions are only achieved if consumers operate the stove correctly. Many don't.

"We need stoves that incorporate best practices in combustion engineering to maximize efficiency and drastically reduce particulates and carbon monoxide. Then, wood stoves will be able to meet even more of our residential heating needs," said Mark Knaebe, one of the judges and a Natural Resource Specialist at the USDA Forest Service.  

The 14 winning teams are: Dragon Heat, The Firemaster, Helbro Stoves, Hwam, Intercontinental, Kimberly, Ofenbau & Feuerstein, SmartStove, Travis Industries, Tulukivi, University of Maryland, Walker Stoves, Wittus and Woodstock Soapstone. 

"The competition brings together innovators - whether established manufacturers or backyard inventors  - to improve America's most widespread residential renewable energy device, the wood stove. We've seen how technologies like oxygen sensors and catalysts have made today's automobiles far less polluting. We're excited to help encourage a similar technological revolution in wood stoves," said Jim Meigs, judge and Editor-in-Chief ofPopular Mechanics.          

Most of the teams represent established wood stove companies, but five are independent inventors and engineering students who have never brought a stove to market. Some are looking to sell their inventions to manufacturers and others are looking for recognition so they can ramp up production.

The Grand Prize and second and third place winners will be selected during the Wood Stove Decathlon, held on the Washington National Mall and open to the public in November 2013.

For more information, visitwww.forgreenheat.org/stovedesign.html.

Masonry Heater Workshop Oct. 26-31 or Oct 28-31, 2012

Masonry Heater Workshop Oct. 26-31 or Oct 28-31, 2012

  

Masonry Heaters are clean-burning heating appliances that use the renewable resource of wood for fuel. They are site built, with a core that is hand-built or pre-cast.  Masonry heaters use no electricity, gas, fans, or duct work, and work by storing heat in a thermal mass, then emitting radiant heat to the living space. Find out why Masonry Heaters are the best heating option today! Masons, skilled homeowners, and contractors interested in learning new skills will want to attend this intensive training session. 

  

The Heater Mason Development Program(HMED) has proven to be an excellent tool to learn more about masonry heaters. The curriculum is designed as an introductory course for masons or homeowners who want to know more about the heating appliance. This course may be used as a "professional credential" good towards the Certified Heater Mason program.

  

The workshop is being held October 26 - 31, 2012 near Sullivan Missouri, near St. Louis. Workshop participants will learn how masonry heaters work, and participate in the the basics of heater building,  hands-on heater core building, and hands-on oven core installation. A heated bench and wood-burning cook stove are also part of the program. This workshop is an approved HMED program for those wishing to become Certified Heater Masons.

  

The class schedule is as follows:

October 26-27: Intensive classroom training with HMED approved credit towards Certification (Certified Heater Mason). Heater builders who wish to be Certified Heater Masons can apply credits for this course. Other builders are encouraged to attend in order to learn the basics of Masonry Heaters which is extremely important! 

October 28-29: Hands-on workshop- build a contra-flow masonry heater with bake oven and heated bench.

October 30 -31: Hands-on workshop bonus- Build a wood-fired cook-stove!
.

Those wishing to stay longer to assist with the exterior finishing work are welcome.

  

The project instructors are Jerry Frisch, owner of Lopez Quarries in Everett, Washington, Gary Hart, owner of Aaron's Ltd. Alternative Energy in High Ridge, Missouri, and Gene Padgitt, Vice President of HearthMasters, Inc. in Kansas City, Missouri. All three are Certified Heater Masons. Jerry Frisch is a master heater builder.

  

Cost for the four-day HMED workshop is $795 for MHA Members and $900 for non-members, plus bonus two-day cook stove workshop.  ALL 6 days!

Or 

$400 for non-HMED participants: attend any four days from Oct 28 - 31!

  

CEU's have been approved for CSIA and NFI. 

Visit www.mha-net.org or call Richard Smith, Executive Director, at   520-883-0191 for more information or to register for the workshops. Get your motel reservations in now! E-mail mha.association@yahoo.com  

When the Wind Blows - its Cold: The indoor wind chill factor

By Doug Hargrave
Mid-Atlantic Masonry Heat

Everyone has experienced the cooling effect of a strong wind or breeze while engaging in some outdoor activity. The extent of the cooling effect is determined by the speed of the wind and the temperature of the air. For example, a warm breeze has to be significantly stronger than a cool breeze to produce a cooling effect. The cooling effect of wind can be moderated by the use of insulation and/or a wind breaker. Someone is more comfortable wearing a wind breaker in a strong breeze. In a strong winter breeze one would have to add a sweater (insulation) under the wind breaker in order to achieve the same relative comfort. When weathermen talk about outdoor temperature condition they often refer to the wind chill factor. The wind chill temperature is always lower than the air temperature. The movement of air indoors is not generally referred to as "wind", however, the effect of air movement indoors is the same as outdoors - it has a cooling effect - it does not make you warmer. Air movement is often introduced into indoor living areas in a number of different ways; a few of the prime examples are as follows: Outdoor air infiltration that causes noticeable drafts through leaky doors, windows and other openings. Forced air systems and fans that mechanically move the air Natural convection of air from a hot radiator surfaces in the primary living areas. The most uncomfortable type of indoor air movement (draft) is outdoor air infiltration that causes noticeable drafts. Just as you would wear a wind breaker for comfort in windy outdoor conditions you want the shell of your home to act as a wind breaker for indoor comfort. No amount of insulation will help if you have drafts from the outside blowing in around it. The only way to counteract the effect of this type of indoor wind chill is massive amounts of hot air which will mask the effect of the infiltration. However this is accomplished at a high energy cost and only marginal improvement in personal comfort. The first line of defense in any home heating plan is reducing the air infiltration so that drafts from the outside are not noticeable. Only after this problem is fixed should someone turn their attention to other issues in the home heating plan. In the United States the use of forced air heating systems is so pervasive that it is difficult for most people to imagine any other way of heating their home. The fact that these systems produce indoor wind chill is accepted as a necessary evil. These systems typically force heated air into a room at the outside walls (usually under the windows) and then extract return air from locations high on interior walls. This forced air ducting arrangement results in relatively strong drafts at the ceiling level while minimizing drafty conditions at floor level. In a room with standard eight foot ceilings the movement of the heated air at ceiling level mixes fairly well with the cooler air lower in the room but there is always a marked temperature difference between the warm ceiling and the cold floor. In rooms with higher ceilings (especially vaulted ceilings) the mixing results of warm air near the ceiling and cooler air near the floor is compromised by the greater separation and larger volume. In order to compensate for this, more heated air is required and more mixing of air is required. This results in more air movement and more indoor wind chill. It is not unusual for someone seated in a vaulted ceiling room during cold weather to wrap a blanket around them self as a shield from this intensified indoor wind chill. Hot radiators cause air movement through natural convection which is then felt as indoor wind chill. The best known example of this is the wood stove where surface temperatures often run between 400 - 600 °F. At these temperatures when the air in the room makes direct contact with the stoves surface it expands dramatically and quickly rises to the ceiling. Other air follows behind creating a draft at floor level in the direction of the stove. This draft is quite cool because it comes off the coolest surfaces in the room usually the least insulated window areas. The wind chill effect from the combination of hot stove surfaces combined with cold window surfaces is very noticeable. Less noticeable wind chill is felt from electric resistance or hot water radiators placed on outside walls (usually under windows). These radiator heat systems send heated air up along the cooler surfaces in the room to the ceiling level. Cooler air to replace the heated air is drawn along the floor toward the radiator but it comes from warmer areas of the room resulting in less indoor wind chill than with a wood stove or other centrally located radiators that would tend to draw air from the outside walls and windows. The question is often asked, "Wouldn't it be a good idea to use a ceiling fan to blow the hot air near the ceiling down to the floor or reverse the fan and draw the cool air up to the ceiling?" On close examination, this solution, could come right out of the pages of Alice in Wonderland. When the ceiling fan is used in the winter time to "blow" the warm air down you almost always can see the slowly turning fan blades, which means it is not really blowing the warm air down but rather just stirring it up at the ceiling level. If the fan were actually run at a high enough speed to blow the air down (or draw the air up), the wind chill factor in the room would increase substantially and your comfort would decrease. On the other hand, in the summer time, when you have hot air at the ceiling and relatively cooler air at the floor, you can turn on the ceiling fan, force the hot air down on you and the indoor wind chill will make you feel cooler and more comfortable. The fan cools in winter and it cools in summer - period.

Types of Heat Transfer

By Doug Hargrave

Mid Atlantic Masonry Heat
radianthomeheating.org

Radiant heat is transmitted from a warm object to a cooler object through infrared radiation. This is the same type of heat transfer that takes place when the rays of the sun shine on the earth. The distance between objects, their surface area and their temperature difference affect the rate of the radiant heat exchange. A good example of radiant heat transfer is the warmth you feel when you sit close to another person. Another example would be the way a radiant heater warms the surfaces and objects inside a home rather than the air.

When the distance between two solid objects of differing temperatures goes to zero and they come into direct contact, the heat exchange between them is then called conduction. Conduction between solid objects results in a faster rate of heat exchange than that of radiation. A good example of this difference is the amount of heat one would feel holding their hand just above a hot stove (radiation) versus actually touching the stove (conduction).

Heat transfer within solid objects is accomplished through conduction. The heat storage capacity and the transfer rate will vary with different solids. For example, the higher density of soapstone allows it to absorb and then radiate more heat per unit volume than common brick which has a lower density. The heat transfer rate within metals is much faster than the transfer rate within masonry materials.

Heat transfer within gases is quite different from heat transfer within solids. Gases have relatively little mass (weight) and very little density (weight per unit volume) when compared to solids. Unlike solids gases can dramatically expand or contract their density. Their density expands when they are heated and contracts when they are cooled. Warm gases that are expanded are lighter than cool gases that are contracted. The difference in weight causes warmer gases to rise and cool gases to fall creating movement within the body of gas. This movement is called convection. The speed of the convection (movement) is largely determined by the how much and how quickly heat is introduced into the body of gas. For example, a 600 degree wood stove causes much more convection (air movement) than a 200 degree masonry heater in the same living area.

PRICIPLES OF RADIANT HOME HEATING

By Doug Hargrave
http://www.radianthomeheating.org 

 

Graphic courtesy of Valor

Understanding the differences between conduction, radiation and convection heat transfer is relatively easy. Understanding how they relate to each other in a radiant home heating situation is much more complex. To some degree conduction, radiation and convection exist in all types of home heating systems; however the proportions of each can be quite different from system to system. This difference in proportions will affect the comfort within the home and the efficiency (cost) for heating the home.

TYPES OF HEAT TRANSFER
Radiant heat is transmitted from a warm object to a cooler object through infrared radiation. The distance between objects, their surface area and their temperature difference affect the rate of the radiant heat exchange. A good example of radiant heat transfer is the way in which the sun warms the surface of planets in the solar system. Another example would be the way a radiant heater warms the surfaces inside a home.

When the distance between two solid objects of differing temperatures goes to zero and they come into direct contact, the heat exchange between them is then called conduction. Conduction between solid objects results in a faster rate of heat exchange than that of radiation. A good example of this difference is the amount of heat one would feel holding their hand just above a hot stove (radiation) versus actually touching the stove (conduction).

Heat transfer within solid objects is accomplished through conduction. The amount of heat applied to the surface of the object, the amount of mass (weight) the object has and the density of the mass (weight per unit volume) affect the rate of conduction within the solid object. For example, the higher density of soapstone allows it to absorb and radiate more heat per unit volume than common brick of a lower density.

Heat transfer within gases is quite different from heat transfer within solids. Gases have relatively little mass (weight) and very little density (weight per unit volume) when compared to solids. Unlike solids gases can dramatically expand or contract their density. Their density expands when they are heated and contracts when they are cooled. Warm gases that are expanded are lighter than cool gases that are contracted. The difference in weight causes warmer gases to rise and cool gases to fall creating movement within the body of gas. This movement is called convection. The speed of the convection (movement) is largely determined by the how much and how quickly heat is introduced into the body of gas. For example, a 600 degree wood stove causes much more convection (air movement) than a 200 degree masonry heater in the same living area.

RELATIONSHIPS BETWEEN TYPES OF HEAT TRANSFER

Home heating systems employ some type of heated surface which is used to transfer heat into the home. The heated surface may take different forms and be in different locations.

For example:

• Forced Air Furnace - located outside the primary living area with a heat exchanger that heats air which is then circulated via ducts to rooms in the primary living area. The air enters the primary living area from the duct work under pressure and is forced to return to the furnace through another set of ducts.
• Hot Water Baseboard Furnace – located outside the primary living area with a heat exchanger that heats water which is then circulated via pipes to rooms in the primary living area. In the primary living area the heated water runs through a baseboard heat exchanger warming room air which then circulates by natural convection.
• Electric Baseboard Heat – located in the primary living area with a heat exchanger that heats air which then circulates by natural convection.
• Hot Water Radiator Furnace - located outside the primary living area with a heat exchanger that heats water which is then circulated via pipes to rooms in the primary living area. In the primary living area the heated water runs through a radiator. The radiator must have enough mass to store the heat from the incoming water. The heat in the radiator dissipates into the room through a combination of natural radiation and convection. The proportion of radiation versus convection is dependant on the size, design and location of the radiator in the room.
• Hot Water Radiant Floor Furnace - located outside the primary living area with a heat exchanger that heats water which is then circulated via pipes to rooms in the primary living area. In the living area the heated water runs through a network of pipes imbedded in the floor giving up its heat to the mass of the floor. The floor gives up its heat to the room largely through natural radiation and some conduction to the objects in direct contact with the floor. Convection from the floor is minimal in comparison to heat transfer by radiation and conduction.
• Electric Radiant Floor Elements – located in the primary living area with heating elements embedded in the mass of the floor. The floor gives up its heat to the room largely through natural radiation and some conduction to the objects in direct contact with the floor. Convection from the floor is minimal in comparison to heat transfer by radiation and conduction.
• Wood Stove – located in the primary living area a heat exchanger (firebox) heating relatively little thermal mass. The heat dissipates into the room mostly through natural convection and some through radiation. The proportion of radiation versus convection is dependant largely on the temperature which the stove is operated.
• Masonry Heater – located in the primary living area with a heat exchanger (firebox) that heats its substantial thermal mass. The heat stored in the thermal mass dissipates into the room mostly through natural radiation and some through convection. The proportion of radiation versus convection is dependant on the size, design and location of the masonry heater in the room.

In the descriptions of home heating systems enumerated above I have given some general indication as to the proportions of the various heat transfer types for each system. I would now like to group these systems in some general proportional categories.

• Convection - Forced Air Furnace, Hot Water Baseboard and Electric Baseboard heat predominately by convection.
• Convection/Radiation – Wood Stoves heat predominately by convection with radiation accounting for a smaller amount.
• Radiation – Hot Water Radiant Floors and Electric Radiant Floor Elements heat predominately by radiation with a small amount by convection and very little by convection.
• Radiation/Convection – Hot Water Radiators and Masonry Heaters heat predominately by radiation with convection accounting for a smaller amount.

 Tulikivi brand Gemini Fireplace

The common element that is present in category 3 and 4 heat systems and is missing in those of category 1 and 2 is the presence of significant thermal mass for heat storage. The thermal mass present in large radiators, floors and masonry heaters significantly lowers the temperature of the heated surface area that transfers heat into the home. When these surface area temperatures stay in the 75 to 150 °F range heat transfer by radiation will predominate. Between 150 to 300 °F range heat transfer by radiation and convection will even out. Above 300 °F heat transfer by convection will predominate.