What Is The Appropriate BTU Rating For a Propane Gas Fire Pit?
How many BTUs do I need for a fire pit for larger flames and more heat? Does a higher BTU rating mean larger flames and more heat? These are common questions among many buyers of gas fire pits and many resources will tell you that the higher the BTU rating of fire pit the larger the flames and heat generated. Well, I’m going to go ahead and say NO. A higher BTU rating in a fire pit does not necessarily mean more heat or taller and robust flames. I will be explaining why this is so shortly.
BTU standards for British Thermal Units and one way to describe this in simple terms is the unit that measures the heat generated by the burner or you could also describe BTU as the heat value of fire pit fuels- Propane, natural gas etc. So if we were to go with these definitions then ‘the higher the BTU rating the bigger the flames and the more the heat generated’ holds true and usually, propane is the preferred gas because it gives of more heat per pound (higher BTU rating) than natural gas or ethanol gas. True when holding all other factors constant.
See I underlined ‘holding all other factors constant’? I did that because for most of the time the higher the BTU rating of a fire pit, the more the heat it is supposed to generate. You see however, this may not always be the case because there are other factors that will also determine the heat generated and the fire pit flame height, hence why I said that a higher BTU does not necessarily translate to larger flames and more heat.
Ever wondered why your fire pit with a BTU rating of 58,000 does not seem to generate enough heat or has weak flames? A high BTU rating is good and all, but there are these other factors that will determine whether the fire pit will be able to operate at its optimal with the given BTU rating. A high BTU rating is only effective if the burner is able to work efficiently to generate this heat. You see there are other factors that facilitate this process so that your fire pit burner so that your fire pit can operate optimally and generate the required heat.
If you have two fire pits, one with a BTU rating of say 30 and the other 100 it is expected that the two operate at different gas pressures in order to generate heat as they should. Obviously, the one with the BTU of 100 will need more gas pressure. So in this case, the BTU rating indicates how much pressure will be required in the gas burner so that the burner can operate at maximum with the rated BTU. The more the BTU the more the pressure you need. So sometimes when your fire pit has a high BTU rating but you find that you’re not getting enough flames or heat, know that the problem might not be the fire pit but rather, the pressure with which the gas gets into the burner.
If there is enough pressure at the source (from LP tank) all the way into burner, then your fire pit should be able to generate enough heat to keep you warm. Keep in mind also that there are also other factors can affect the gas pressure for example the distance traveled by the gas because of the length of the hose pipe and the number of corners the gas has to cut before finally reaching the burner. So it goes without saying, the shorter the hose pipe the higher the pressure and the more the pressure at the source (LP gas tank) the better.
Orifice size and amount of air mixing with the gas
Another factor that will determine how efficient the chosen BTU burner is the fire pit orifice and how much air mixes with the gas to produce flames. The larger the orifice the better and the more the air allowed to mix with gas in order to produce optimal heat and flames with the burner with the given BTU rating, assuming the factors such as pressure are good of course.
Design of the burning system
Another reason why your fire pit may have a high BTU rating but your flames are not robust and there isn’t enough heat generated is because of how your fire pit’s burning system is designed. There are fire pits that designed with the gas ports hidden underneath the burner pan so that heat is trapped beneath the burner before it can finally get over the top to get you warmed up, so much of the heat is lost in the process. So to avoid this, go for fire pits with the gas ports extending out over the burner pan so no heat is lost beneath the burner pan.
So you see why I said when all other factors are constant a higher BTU rated fire pit is supposed to give off more heat? From this, you can see that a higher BTU rating does not automatically mean your fire pit will generate the amount of heat you need it to in order to keep you warm. A high BTU rating in a fire pit is only effective only if the other conditions are efficient.
If your fire pit has a high BTU, design is good-no gas ports hidden beneath the burner pan, gas pressure is good, orifice size okay, then you can expect your fire pit to generate enough heat to keep you warm during those cold chilly nights.
Since most outdoor propane fire pits are designed while taking most of these other factors into consideration, best go for a fire pit with a higher BTU rating if you’re looking for a fire pit solely for warmth. And you can get the general idea of whether said fire pit generates enough heat by going through customer reviews and seeing what others have to say about it.
Remember, the higher the BTU of the fire pit burner, the more the fuel it will consume which means the higher it will cost you to run the fire pit. If this option proves to be too expensive if you’re looking for an everyday fire pit to keep you warm, you could incorporate another source of heat such as a heater with your gas fire pit or go for a wood burning fire pit. But if you’re looking for a fire pit with high a BTU rating, Here Are Some Popular Options.
Feel free to leave us any questions or comments you may have in regards to this below and we will be more than happy to get back to you.