Wood Stove Innovation: A Blaze of Progress

Published by Christy Reed on

Wood Stove Innovation: A Blaze of Progress

Noel Putaansuu

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For centuries, wood stoves have provided warmth and comfort in homes around the world. Just like any other technology, wood stove design and efficiency have continuously improved. While the current certification process in the U.S. could benefit from increased transparency, there’s no doubt that ongoing advancements in technology are leading to wood stoves that are cleaner burning and more efficient.

For centuries, wood stoves have provided warmth and comfort in homes around the world. Just like any other technology, wood stove design and efficiency have continuously improved.

One such initiative driving innovation is the Cooperative Research and Development Agreement (CRADA) project funded by the U.S. Department of Energy Bioenergy Technologies Office (DOE BETO). This program fosters collaboration between the government, higher education, and the private sector to develop cutting-edge wood stove technologies.

Who’s Involved?

Several companies with promising technologies entered a recent CRADA competition, but only a handful secured funding. The complete list of entrants is unavailable. This lack of transparency highlights the difficulty new technologies face in securing resources. Unfortunately, due to privacy concerns, specific details about participating companies might not be publicly available. We do know the published information, which specifies that HPBA, ISB Marketing (in conjunction with Stove Builder International), NESCAUM, One World Resource (in conjunction with OekoSolve AG), and Smokeless Chimney each won a grant to work with a national laboratory to further develop technology. The two national laboratories are Lawrence Berkeley National Laboratory and Brookhaven National Laboratory.

I reached out to the companies in the peer group. Two responded, and the other statements are from publicly available information sources.

One World Resource Management

Below is a statement from Tom Walter at One World Resource Management, whose project involves researching U.S. market viability and controlling particulate emissions from residential biomass wood heaters with ESPs.

“In efforts to address particulate emissions associated with residential wood heaters (RWHs), this project proposes the integration of electrostatic precipitators (ESPs) as retrofit particulate control devices. ESPs have demonstrated high efficiency in removing fine particulate matter, especially in the PM2.5 size range, across various RWHs. The team will test and analyze the ESPs’ effectiveness with the goal of developing a body of work to give early adopters confidence in the efficacy of the ESP technology on appliances available in the U.S. market. The results of this project could also lead to a national emission testing protocol for ESPs, which could be recognized by the EPA and applied to all testing institutes in the U.S. There is strong justification that this technology, as well as these scientific tests under a very controlled environment, will advance or even accelerate commercial readiness of the technology on wood heaters, resulting in drastically reduced air emissions caused by domestic wood burners as well as industrial biomass boilers.”1

ISB Marketing (Associated With SBI)

The second project summary comes from Guillaume Thibodeau-Fortin at SBI, who has been working on a thermal storage solution for wood stoves that provide constant heat output in an ideal thermal range.

“Wood Stove Latent Heat Transfer Design is a technology development project to evaluate and determine the best thermal storage solution to operate a batch-loading, single burn-rate, steel wood stove with optimal combustion parameters while providing constant heat output in the ideal range for thermal comfort. By integrating a cutting-edge thermal storage unit, this new wood heater technology will solve the problem of room overheating and the problem of poor combustion that can cause safety hazards. This unit is pivotal in achieving a controlled, steady release of heat over extended periods, thereby maximizing energy efficiency. Less wood will be consumed, which leads to fewer emissions and is less expensive to operate. The simplicity of its construction will make it a more affordable, high-efficiency heater, allowing more low-income families to upgrade their stoves instead of relying on older conventional products.”2 

Smokeless Chimney

The next project summary comes from Smokeless Chimney, which is my company. We have been working on the optimization and validation of an opacity emissions sensor to inform a wood stove air supply controller. Here is a summary of the project.

“Today, Smokeless Chimney unites hearth, health, and planet by creating cleaner, more sustainable ways to enjoy the flames of fire. Join us on this journey towards a brighter future, one flame at a time. This project explores a novel approach to managing wood and pellet heaters. Our advanced light opacity technology measures smoke emissions, seeking the root cause of smoke and informs the user and/or the stove control system. Partnering with Lawrence Berkeley National Lab, we’re revolutionizing wood burning, tackling smoke head-on, and transforming every flame into a beacon of cleaner air.”3

HPBA (Project 1)

The Hearth, Patio & Barbecue Association (HPBA) is working on two CRADA projects. The first is the development of a wood stove draft prediction tool to guide manufacturers and installers on wood heater or chimney parameters.

“In wood heater design and emission testing, draft has always been the major confounder that no one in the wood heater community knows how to address. As a result, heaters are all designed for a single-story venting system in a 70°F lab. Designing heaters for these laboratory conditions may ensure successful certification testing, but draft and emissions from the heaters are different when operating in homes. Through this project, the Hearth, Patio & Barbecue Association and Lawrence Berkeley National Laboratory will work collaboratively to develop the draft prediction tool that can guide manufacturers and installers in adjusting heater or chimney parameters that address less-than-optimal draft conditions and help ensure optimal wood heater emissions performance.”4

HPBA (Project 2)

The second CRADA project by the HPBA involves the evaluation of the performance of particulate matter sensor technologies to cost-effectively quantify emissions from wood heaters in the lab and in-situ.

“For approximately 40 years, residential-scale wood heater certification methods in North America measure particulate matter (PM) emissions using an EPA dilution tunnel and gravimetric sampling approach. While this system has proven to be reasonably repeatable, it only provides time-averaged results for the entire operating sequence and is not amenable for estimating varied sequences or high-emission events. Real-time PM monitors have been proposed as a potential solution to this challenge; however, only one PM monitor has been advanced for this purpose. This collaborative project between Hearth, Patio & Barbecue Association and Lawrence Berkeley National Laboratory aims to launch the process for identifying and evaluating suitable PM monitoring technologies for measuring wood heater emissions in the lab and in homes (in-situ).”5

NESCAUM

NESCAUM’s project involves the development and verification of a portable flue gas sampling dilution system for use in the field to assess wood heater emissions.

“This project aims to identify, develop, and verify a portable flue gas sampling dilution system for use in the field to assess residential wood heater (RWH) emissions. To assess portable diluter performance, the team shall use a direct mass-based measurement to obtain particulate matter emission rates comparable to those obtained with a dilution tunnel in the lab. Developing a verified in-situ dilution system creates the capacity for industry, researchers, and regulators to directly compare emission rates between lab conditions versus field conditions, helping manufacturers explore innovative combustion technologies to improve RWH performance. Verifiable field data can demonstrate emission reductions from new RWHs under actual operating conditions. Long-term project goals include fostering new technology development, identifying opportunities for performance improvements, and advancing new wood heater technology innovations, with the co-benefits of increased energy efficiency for consumers, more sustainable biomass energy for communities, and cleaner air.”6

A Brighter Future for Wood Stoves

There’s no doubt that the CRADA project, along with other research efforts, will lead to significant advancements in wood and pellet stove technology. These advancements can translate into several benefits:

  • Cleaner Burning: New technologies could significantly reduce harmful emissions from wood stoves, improving local air quality.
  • Improved Efficiency: More efficient stoves will get the most heat out of every unit of wood fuel, saving users money on firewood and pellets.
  • Retrofit Options: The project may explore solutions to upgrade existing wood stoves with cleaner burning technology.

These advancements promise a brighter future for wood stoves, ensuring they remain a viable and environmentally responsible heating option.

This article is brought to you by Associated Energy Systems.

The availability of new technologies with these benefits depends on several factors, including the research timeline and commercialization process. The time is coming for field measurement on installed wood stoves. While specific dates are difficult to predict, the CRADA project focuses on short-term projects (12-18 months), suggesting potential developments within the next few years.

Stay tuned to The Fire Time Magazine for further updates on the CRADA project and other wood stove innovation initiatives. These advancements promise a brighter future for wood stoves, ensuring they remain a viable and environmentally responsible heating option.

Footnotes

  1. Electrostatic precipitators are a well-established smoke abatement technology that lowers smoke by capturing smoke particles.
  2. Many wood stove users stack bricks or metal parts on or around the wood stove to increase the heated thermal mass. SBI is looking at options to increase the thermal mass of a wood stove and anything other than bricks or steel parts would be more decorative and possibly more effective.
  3.  Measuring smoke is the first step in reducing smoke. Developing this technology is valuable to evaluating other smoke-reducing technologies in the lab as well as the field.
  4.  Draft is a major factor in wood stove performance. Structures are much tighter and restrictive to airflow. Draft models and measurement procedures will take the mystery and guesswork from wood stove installation.
  5.  Smoke that hangs in the air is measured by small particulate meters. These meters are great for air health and quality. It has been said that one puff of smoke can compromise a meter. Can they be used for wood and pellet emissions?
  6. This project appears to be taking the lab out to the field and using laboratory techniques to measure smoke from installed wood stoves in the field.
Noel Putaansuu

Noel Putaansuu

Noel Putaansuu is the Owner of Smokeless Chimney. With more than 35 years of experience in the fire sciences, he has participated in the industry from the research and development perspective, and he has also managed a large portion of the U.S. fire claims for insurance companies. He believes in warm homes and clean air for everyone.

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