January 7, 2019

What is the most efficient wood to burn in my fireplace? Do some types of wood burn better than others? How can I maximize my wood fire? How can I generate more heat from my fire? How can I make the wood burn slower and last longer? 

These are great wood burning questions that we get from our customers. Since Acucraft has been engineering, designing and building wood burning fireplaces for over 40 years, we’ve learned a lot about wood burning fireplace efficiency and performance.

How To Maximize Your Wood Burning Fireplace Performance

1. Wood Quality and Burn Efficiency

The quality of wood is so important for an efficient wood fire. This means that the wood needs to be cut, split to less than six-inches in diameter, and stored in a dry location  until the moisture content is between 18-22%. The only way to truly know the moisture content of the wood is to measure it with a wood moisture meter. Burning dry wood will maximize your heat output, keep your glass clean, and produce less creosote buildup.

The type of wood you burn in your fireplace impacts your heat output as well. Dry hardwood, such as oak or maple, are great choices.

The wood you use in your fireplace impacts your heat output. Use dry hardwood, such as oak or maple, with a moisture content between 18-22%.

2. Combustion Air Settings and Heat Production

The outside combustion air to the firebox regulates the amount of fire and heat your wood will produce. The combustion air enters your Acucraft firebox at the top of your door opening. Combining the right combustion setting with choosing to burn quality wood will keep your fireplace glass clean.

More combustion air will be needed when you start a fire or if you are burning wood with a higher moisture content.  If you do not have enough air to the firebox your glass may darken.  

3. Damper Down to Lengthen Burn Time

The damper settings control the length of burn time in your firebox. The lower your damper settings, the longer the burning time. However, if you damper down too often, the downside is that there will be more creosote buildup in your flue, which can be dangerous if your flue system is not professionally maintained.

Acucraft highly recommends that you have your flue professionally inspected and cleaned every year to remove creosote buildup and to ensure that your fireplace is performing safely.

The most common causes of creosote buildup are burning soft, moist, or wet wood, and using newspaper as a fire starter. Safer choices for fire starter are using wax and sawdust fire starters or small, dry sticks and twigs—they work great with kindling.

If you use your fireplace often, use a creosote spray a few times per wood burning season to minimize creosote buildup between chimney sweeps. A creosote spray will not replace the need for an actual chimney sweep with a brush, but will help to maintain a cleaner fireplace and chimney system.

4. Outdoor Air Temperature & Its Impact on Fireplace Performance

If you live in a climate with outdoor air temperature shifts from one season to another, you’ll noticed that your fireplace will perform differently unless you make changes to the Combustion Air Controls to adjust burn time and heat production.

For instance, if you last used your fireplace on a summer evening and then started a fire in the middle of winter, you’ll notice that your fireplace will burn hotter and faster than it did the last time you used it. What happened?

Outdoor air temperature impacts chimney drafting and how well your fireplace performs. Cold outdoor air is lighter and travels faster, and warm outdoor air is heavier and travels slower, so fireplaces burn hotter and faster in cold weather.

Knowing this, you’ll  need to adjust your Combustion Air Controls to help your fireplace perform to its best. During warmer seasons, open your Combustion Air Controls more fully, up to 100%, to allow more air in. During colder seasons, close the Combustion Air Controls to about 50%. This will reduce airflow to your fireplace and help keep your fireplace glass cleaner.

Not all chimney systems draft exactly the same. So when you notice your fireplace burning too fast or not enough, just adjust your Combustion Air Controls to discover what settings work best for your wood fireplace.

Outdoor air temperature affects chimney drafting. Open your combustion air controls more during warmer weather and close to about 50% during cold weather.

Looking for the perfect fireplace for your space? Connect with one of our expert Fireplace Advisors today! (888)317-6499 or [email protected] 

Click Here to request a copy of our Wood Fireplace Catalog.

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