Fire pits are a great addition to every yard, but we have all, on occasion, wished they were just a little bit hotter. In this article, we will explore the various ways you can turn up the heat in your outdoor fire pit.
Hardwoods Burn Hotter for Longer
The wood you choose will greatly impact the heat output of the fire you produce. Generally speaking, hardwoods such as oak, birch, and maple have denser fibers and will produce more heat and burn for a longer period of time per log than their softwood counterparts.
Conversely, softwoods such as pine and cedar will burn for a shorter period of time and produce less heat overall. That said, a softwood fire will typically have larger sparks and flames than a hardwood fire.
There are other factors to consider when you next set out to buy firewood, such as how much smoke they produce or even the sound of the crackle. You can read our guide to choosing wood for your fire pit here.
A Quick Word On BTUs
Heat output can be measured in British Thermal Units or BTUs, and that is the standard measurement unit for firewood, coal, natural gas, and other types of fuel commonly burned for the purpose of heating an area. Put simply; a single BTU is the measure of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
Here is an example: A cord of hickory wood produces 28 million BTUs of heat. A cord is 128 cubic feet of tightly packed wood, usually in a 4' x 4' x 8' stack or similar.
Similarly, one ton of anthracite coal produces around 26 million BTUs.
Here are a couple more examples of both hardwoods and softwoods and their BTU values per cord.
Apple - Hardwood, 27 million BTUs, few sparks, fragrant.
Birch - Hardwood, 20 million BTU's, few sparks, medium smoke, slight fragrance.
Pine (Ponderosa) - Softwood, 16.2 million BTU's, many sparks, some fragrance.
Cedar - Softwood, 13 million BTUs, medium sparks, fragrant.
A helpful resource for checking the thermal properties of various firewoods can be found here.
Excellent Choices For A Hot Burn
Any well-seasoned, dry hardwood with a decent BTU value is going to be an excellent choice for a hot burn.
Preferred firewood used by veteran fire enthusiasts is pinion, a widely available hardwood that provides 27 million BTUs, with many sparks and crackles. Pinion is sometimes referred to as the hardwood of softwoods, as it possesses the excellent thermal properties of hardwood with some of the great attributes of softwood such as crackles and sparks. It's also great for repelling insects.
Wood Typically Burns Hotter Than Gas
It's worth noting that wood fires typically burn hotter than gas pits, especially when using the correct fuel. This information shouldn't have you changing your pit, but if you are thinking of installing one in your yard and you crave heat, it's worth noting.
Getting Oxygen in Your Pit
Oxygen is an essential element in the combustion process in a fire. Increasing the airflow inside your pit, thereby adding oxygen, will have an immediate and noticeable impact on your fire. This is the same effect that occurs when you gently blow on an ember in your kindling.
Strong ventilation in the construction of your fire pit will help provide airflow, as long as they are not covered with ash and debris from a previous fire.
Somewhat comically, you can also employ a set of manual or electronic fire bellows that will pump air into your pit.
Building the Correct Structure
As we just talked about getting more oxygen in your pit, an excellent way to do this is by building a structure that offers superior airflow.
One such build is the classic Teepee. The Teepee is a cone-shaped leaning structure that allows airflow between the pieces and enables the operator to add more wood as needed.
To provide for even more airflow, try stacking your wood as loosely as possible. Tightly packed fuel can prevent oxygen from reaching the center of your fire and prevent its maximum heat potential.
When you have exhausted your options for raising the temperature of your fire pit, and you still are not satisfied, it's time to think about keeping the heat in and around the pit area to increase warmth.
Using a fire pit deflector, which sits above your fire and pushes heat down and out to the sides, you can effectively direct the flow of heat from the fire. Rather than the heat going up into the cold air directly above the fire, a deflector will guide the heat towards you and your guests.
A fire pit deflector won't make your fire hotter and could even enhance the beauty of the fire, depending on your personal opinion. Still, they are sure to make the heat more useful and provide more of a warming effect to your guests.
Sunken or In-Ground Fire Pits
Again, this one probably isn't the best tip if you're reading this on a cold winter's night with an above-ground fire pit already roaring in front of you, but it's worth thinking about.
An in-ground fire pit is one that, as the name implies, is built within the structure of the ground below. That means the heat generated from the pit will rise to the bodies of your guests rather than needing to be directed towards them.Aside from the heat, sunken pits are generally a little safer. The fire is contained in cold, hard ground or surrounded by fireproof material depending on the construction, meaning it has little to nowhere to go. In-ground pits also tend to be a little smaller, as the amount of heat needed to warm your guests is reduced as it is more efficiently used.