A Note About New Super-Efficient Wood Stoves

26 May 2021      

Wood stoves have evolved over the years from being smoldering, chimney clogging, (massive amounts of) wood burning slobs ‐ to being a clean end efficient heat source that is a nearly net zero carbon environmentally friendly, cost efficient home heating energy source.

A wood stove in its primitive form is a steel, cast iron or stone box with an air intake hole and an exhaust connection. Unlike a furnace, the firebox has no moving parts and is given its breath passively, by utilizing chimney heat exclusively. Hot air rises, creating draft, and the more air flowing (draft) through the stove and chimney, the more vigorous light off and apparent lively combustion is. However, the chimney is powered by wasted heat only. The firebox designs of the 21st century is moving to efficiencies never imagined 25 years ago. Suppose there is less wasted heat?

HearthStone’s family of TruHybridTM technology stoves and inserts comprise the best efficiencies and cleanliness available today. Congress has rewarded these “best of the best” products with the 25D tax credit starting in 2021. HearthStone’s high quality, Uber‐Efficient classics will burn fuel at true efficiencies up to 81 %. You will be eligible for a full 26% Tax Credit for the entire installation!

It is more important than ever that chimneys are up to standard and ready for these uber‐ efficient stoves of today.

If an old school stove operates at 45% efficiency, 55% of the energy is going up the chimney in the form of heat and creosote. An 80% efficient heater only has 20% of the heat available to drive the chimney. It must burn slower to allow for the heat to pass to the room. You will use less fuel.

We need to consider the best chimney design, the best methods for burning wood in these stoves and inserts and well‐seasoned, dry fuel.

1. A good Chimney must be insulated and of sufficient height to create a draft adequate with minimal heat loss.
   1. Draft can be measured. Your chimney professional is able to measure actual draft reading. (“0.08”‐0.10” H2O is a minimum range draft for a super‐efficient stove)
   2. An insulated stainless liner is best for a masonry chimney. Exterior masonry chimneys require a heat up process which may take a little patience.
   3. Elbows are a restrictor. Each one adds the need for more vertical height (4’ of additional chimney for each elbow more than 1)
   4. Horizontal runs must have slight upward slope, never down.
   5. Use a “packed” insulation type chimney for new work. Air‐cooled triple wall chimney will not get hot enough and should not be used.
   6. If Santa can fit down it, it will not work!
2. Make a fire. Starting a fire is best done with a “top‐down” method for two reasons:
   1. . You will spend less time in front of your stove fussing with it. As little as one match will do it.
   2. You will quickly establish higher temperatures in the top of the stove and get the chimney working more quickly.
      (There are many videos on YouTube describing this method: search “top‐down fire” or go to: (https://www.youtube.com/watch?v=NtUUwZE YHBo )
      (https://www.youtube.com/watch?v=CgKCBnx m3ig )
3. Use only seasoned wood. Unseasoned or wet wood will not provide enough heat to drive the chimney as the heat is wasted cooking off the water in the wood. This is what seasoned, dry firewood looks like. 

In summary, whether you are new to wood heating, or are replacing an old‐school stove with a modern one, it is important to have the right chimney, the right methods, quality fuel and the right expectations.

Stay warm and know that you are making a good choice for your budget and the environment by burning the most renewable energy source there is: WOOD

Thank you for choosing a Quality Clean and Uber‐Efficient HearthStone heater!

Source: https://www.hearthstonestoves.com/