If you’re like me, then you love spending time outdoors cooking food on a bbq smoker. There’s nothing quite like the taste of smoked meat.
But, whether you’re just looking into buying a smoker or building your own firebox, you need to know how big your firebox should be.
The size of the firebox will affect how long it takes to cook your food. So, it’s important to get it just right.
On average, the smoker’s firebox should be 1/3 of the total volume of your smoker. A very large offset smoker is an exception; then the firebox should be 1/2 the size of the smoker.
Of course, the size of the firebox also depends on the type of smoker you have.
The bottom line is that you need to know the size of your smoker in order to determine the appropriate size for your firebox.
With a little bit of planning, you can ensure that your smoker works perfectly and that your food comes out tasting great.
Follow these tips and you’ll be sure to find the perfect firebox for your smoker.
In this post we'll cover:
- 1 How big does the firebox need to be on a smoker?
- 2 Is firebox size important for smokers?
- 3 Building your own firebox and/or smoker
- 4 What does a firebox do on the smoker?
- 5 What if the firebox is not the correct size?
- 6 Takeaway
How big does the firebox need to be on a smoker?
There’s something you ought to know about the size of a firebox on a smoker. There are many different models, so it’s important you know how big your firebox should be.
A good rule of thumb is that if the size of your firebox is smaller than the capacity of your smoker, then it will take longer for food to cook.
If you have a larger firebox, it will cook the food faster. But, be careful not to make the fire too big, or else you’ll risk ruining your food.
The size of the firebox will also affect how much wood you’ll need to use. If you have a smaller firebox, you’ll need less wood. If you have a larger firebox, you’ll need more wood.
In general, your firebox should be about 1/3 of the size of the smoker. This ratio ensures that the fire will be hot enough to cook the food, but not so hot that it will ruin the food.
Or think of it like this: the size of the firebox should be about 20-30% of the total size of the smoker. So, if you have a smoker that’s 30 inches long, the firebox should be about 6-9 inches long.
Keep in mind that the size of the firebox is just one factor to consider when choosing a smoker.
You’ll also need to decide on the type of smoker, the material it’s made from, the fuel it uses, and the size of the smoker.
But, if you keep these things in mind, you’ll be able to find the perfect smoker for your needs.
Just remember to keep the rule of thumb in mind, and you’ll be sure to find the perfect firebox for your needs.
What about different types of smokers?
There are many different types of smokers, and the type of smoker determines the size of the firebox.
The firebox size should correspond to the smoker size, whatever shape it may be.
Generally, the same rule goes for any type of smoker: the firebox should also be 1/3 of the total size of the smoker whether it’s a horizontal smoker or any other type of charcoal smoker (except larger offset smokers).
There are exceptions to the rule, however.
For example, large offset smokers have larger fireboxes because they need to accommodate more wood.
If you’re using an offset smoker, then your firebox should be 1/2 the size of your total smoker.
Reverse flow smokers are a type of smoker that has a firebox located at the side of the smoker.
The size of the firebox on a reverse flow smoker should be about 20-30% of the total size of the smoker.
Is firebox size important for smokers?
The size of the firebox will also affect how much wood you’ll need to use.
If you have a smaller firebox, you’ll need less wood. If you have a larger firebox, you’ll need more wood.
A good firebox requires good oxygen and has room to build a fire with 5 to 7 wood chunks.
This firebox creates a warm environment for food and keeps the temperature in the cooking chamber steady.
The size of the box has no relationship with the food chambers. Why? It’s possible that even 4-5 chunks could sustain temperatures in a 1000 gallon smoker.
Some suggestions on the web have been made for making the firebox correspond to the proportions of food inside – it simply doesn’t work that way.
Where is the firebox located on a smoker?
The location of the firebox will depend on the type of smoker you have.
- On a reverse flow smoker, the firebox is located at the side of the smoker.
- For an offset smoker, the firebox is located beneath the food chamber.
- For a barrel smoker, the firebox is located at one end of the smoker.
These are the three most common smoker types, but there are many other types of smokers as well.
In general, the location of the firebox will not affect how much wood you’ll need to use.
Building your own firebox and/or smoker
If you’re a DIY person, you probably want to try making your own backyard smoker, or at least make your own firebox.
Here’s what you need to know:
Fireboxes usually are small. Wood contains more BTUs than charcoal or briquettes, therefore even small flames produce sufficient power.
I build firebox models using cardboard. It helps save time and money.
Start with a fire holder that measures 50 cm long, 50 cm high, 70 cm deep (20 inches wide x 20 inches high x 20 inches deep).
These sizes can accommodate a lot of backyard smoking machines.
Once again, keep in mind that those very large offset smokers work best if the firebox is 1/2 the size of the smoking chamber.
What does a firebox do on the smoker?
The firebox on a smoker is responsible for two things: generating heat and smoke.
The firebox is where you’ll build your fire. The heat from the fire will cook the food, and the smoke will add flavor.
You can also add wood chips to the firebox to make a great bbq.
You can use any type of wood in the firebox, but some woods are better than others.
Keep in mind that the firebox directly affects the heat distribution and heat airflow. Size also affects how fuel-efficient your smoker is.
What if the firebox is not the correct size?
If you have an undersized firebox or an oversized one, your smoker may not get hot enough, or it can end up being too hot and ruin the cooking process.
As you know, you have to smoke food at a lower temperature than grilling.
If your firebox is too small, it will take longer to cook the food. And, if it’s too big, the food can get overcooked or even burnt.
So, the rule of thumb is that you need a firebox with a one-third volume of your smoker size.
There is no one size fits all answer for how big should a firebox be on a smoker. It depends on the size of your smoker.
The general rule of thumb is that your firebox should be 1/3 of the total dimensions of your smoke – this ensures it can produce enough heat and smoke to cook your favorite smoked meats.
Smaller smokers require a smaller firebox. If you have a larger smoker, then you will need a larger firebox.
It is important to choose the right size firebox for your smoker so that you can get the best results when smoking meats.
Next, check out my complete guide on BBQ smoker baffle plates & how to tune them