Building a DIY propane fire feature, whether it be a fire table or a fire pit, can be both a lot of fun and a bit intimidating when starting your project. Not to worry, Celestial Fire is will help guide you through the entire project. We are available both online and by phone to support you and your project. On this page we’ve put together a lot of information we believe you should know going into your project. By having a good understanding of the fundamentals and how they apply to constructing a fire feature will help ensure you build a fire feature which not only looks amazing but operates safely.
CAUTION! Installing gas appliances can be dangerous. We advise working with a certified Gas Installer.
Propane is Heavier than Air – Design for safe and proper ventilation
The most important thing to remember as you move ahead with your design—propane is a very heavy gas. Propane is heavier than air and will always settle downwards. It can fill your burner pan with gas before igniting, leading to a large initial combustion/flame. It can also fill the enclosure under your burner pan with gas, which is another potential danger. For this reason, you need to have adequate ventilation of at least 200 square inches, in the lowest parts of your enclosure in case of a leak. This will allow any escaping gas to flow down and out. The design we recommend for propane enclosures is to eliminate the floor and have the structure raised an inch or two off the ground. If you plan to have your propane tank inside the enclosure, you will need a support shelf for the tank to keep it off the ground and out of sight.
PROPANE has 3 carbon atoms and 8 hydrogen atoms (C3H8) – NATURAL GAS has one carbon atom and 4 hydrogen atoms (CH4). 50% more carbon in propane makes it heavier than air while natural gas remains lighter than air.
Propane Burns Dirty – How to minimize the soot left behind by propane
When propane burns, not all of its carbon molecules are consumed. This unburned carbon is soot, a black coating on the burner and fire glass. In contrast, natural gas has less carbon so it burns more completely. It’s a “cleaner” burn and results in very little sooting. There are two things you can do to limit how much soot is generated by your propane burner. The first is to add air to the propane by installing an air mixer just prior to the burner. This will introduce more oxygen into the mix and help the gas burn hotter and cleaner. The second thing you can do is add a glass flame guard around your burner. The wind guard protects against breezes that blow the flame around. This could accidentally result in an unwanted fire and it also requires more gas to sustain the flames because the burner has to work harder. If you see soot on the edges of your burner pan, this is a sure sign that you need to add a glass flame guard.
Even with these measures, you will eventually see some sooting with your propane fire feature, but don’t worry – it’s easy to clean. You could gently lay your fire glass or lava rock in the grass and spray it with a hose. Most of the soot should come off. Or you can gently rinse all the soot off using a 50/50 mixture of water and vinegar in a bucket.
YELLOW flames burn ambient air, BLUE flames burn air which is mixed with the gas.
Gas Fittings – Tapered Thread vs Flared
There are two common type of fittings for gas; NPT (National Pipe Thread – or also referred to as National Pipe Taper) and flared (compression). The two fitting types are very different and cannot be connected directly together without a coupling to make the conversion; however, it is common to have a mix of flared and NPT components used in fire features.
NPT uses a tapered thread to provide a seal. Since the threads are tapered, the more you tighten the fitting the tighter the seal becomes. Because the seal is made by the threads, you need to use Teflon gas tape on the threads. Gas-rated Teflon tape is usually a yellow color.
Flared fittings have a flared surface on the tip of the fitting which is pressed against a matching inverted flare to provide a seal. The seal is formed where the two flares meet. The threads do not contribute to the seal. With a flared fitting, the function of the threads is only to apply pressure to the flare. The threads themselves do not contribute to the seal. Therefore, you should not apply any Teflon tape or other sealant to the threads of a flared fitting.
NPT sizes are loosely based on the inside diameter of the gas pipe. As such, 1/2” NPT threads actually measure 0.840”.
Burner Options – Selecting the best type of fire pit burner for your project
Depending on your project, you’ll want to choose the burner option that best matches your needs. Typically, there are two options to choose from; a stand-alone burner ring or a burner and pan kit.
Stainless steel burner rings are a great option for gas fire pit projects where you don’t require a pan under the burner to support the fire glass or lava rocks. A good example of this is converting a bowl into a fire feature. If the vessel is small, it won’t take much fire media to fill it and the burner can sit atop the fire glass or lava rock. Celestial burner rings come in a reversible design. They can be installed with the holes facing upwards or downwards. You should always have the holes facing upward if using propane because it’s heavier than air and by nature, it wants to flow downward. Get it started in the right direction by facing it up toward the sky.
Drop-in burner pans are an easy option for DIYers because the burner is already installed in the pan. All you have to do is drop it in. And though it’s simple to do, it looks as if it’s been professionally installed. The lip of the pan provides support and the weight of the pan holds it in place. There’s no need to fasten the pan to the tabletop. When planning for the burner pan installation, the cut-out for the burner pan should be about 1” larger than the drop-in portion of the pan (the portion that sits below the surface). For example, a 24” x 8” burner pan should have a 25” x 9” opening to drop into. This will allow the pan to easily fit into place and for temperature expansion and contraction. For smaller pans such as the 24” x 8” you can get away with an opening which is only 1/2” larger than the pan (24-1/2” x 8-1/2”) because the pan won’t expand much when heated. With longer pans the expansion is more significant, such as the 48” x 6” pan. Here we recommend the full amount of 1” for the length (49” length opening).
For an easier installation and safer operation, we recommend installing a CSA-certified burner kit. CSA (Canadian Standards Association) burner kits are complete kits. They are safety-certified for both mechanical and electrical operation. These kits are tested as a complete system with all the components installed. So all you have to do is attach it to a propane tank. They include the burner, pan, igniter, thermocouple (flame sensor), hoses, regulator and control knob.
Some key factors to know when considering a CSA burner kit:
- CSA certification is required for commercial installation
- CSA certification may be required by local licensing and permit offices (we highly recommend for shared use such as Airbnb and VRBO rental properties)
- CSA burners have a lower BTU rating as the flame height is limited for safety
A THERMOCOUPLE is a safety feature on CSA burners which will turn off the gas if it senses the flame is no longer burning. It can be identified as a metal rod inside a cage and will have a single flame directed at it.
Propane Gas Hose Options
There are several hose options for your fire feature. Most connection kits will include the hoses, which will be either a rubber hose or stainless-steel flex hose. If the hose will be located where it may be cut or damaged, such as by a weed trimmer, then you should opt for a flex hose. If the hose will be in a cabinet or an area where there’s no danger of it being cut, rubber is sufficient. But beware that not all flex hoses are equal.
- Standard Flex Hose – Standard flex hoses should be avoided. These hoses have ribs which are evenly spaced along its length which can cause a whistling noise. This is because the even spacing of the ribs causes an oscillation effect, which results in a high-pitched whistling sound.
- Whistle-Free Flex Hose – Whistle free flex hoses prevent the whistling noise often heard in flex hoses by changing the rib spacing at various lengths along the hose. The change in rib spacing prevents sound from oscillating and creating a whistling sound.
- Rubber Gas Hose – The most common type of hose is a standard rubber gas hose. These won’t whistle, since the inside of the hose is a smooth surface without any ribs. Rubber gas hoses typically come with most propane regulators and connection kits.
Most DIY burners have 1/2″ NPT fittings, the hoses used for these projects are usually 3/8” with a flared fitting. This is not a problem as a 3/8” hose can deliver more than enough gas to operate your fire feature.
Regulators and Gas Pressure
A regulator is required to reduce the high pressure of your propane tank to the much lower pressure the fire feature requires for operation. Broken down to a simplistic overview of how a regulator works, a regulator contains a spring-loaded diaphragm which will adjust the size of the gas input based on the line pressure. As the pressure rises in the output line to your fire pit, the diaphragm will push back on an input valve restricting the amount of gas entering the regulator. As the line pressure in the regulator drops, the diaphragm opens the input valve from the tank keeping the pressure at the desired level.
Most propane fire features use what’s called a single stage regulator. A single stage regulator drops the gas pressure from the tank in a single step. Single stage regulators are affected greatly by drops in supply pressure (tank pressure). This isn’t usually a problem with fire pits as it’s easy to access and adjust the control valve occasionally to keep the flame at the desired height. Two-stage regulators reduce the tank pressure in two steps. They are much better at maintaining the line pressure as the tank pressure drops, eliminating the need for periodic adjustments of the flame height.
The pressure required for propane fire features is between 7” WC and 11” WC (water column). Water column is the amount of gas pressure required to raise water in a vertical tube a given distance. As a frame of reference, 28 inches WC is equal to 1 PSI. The pressure required for propane fire pits is higher than propane BBQ grills, so want to purchase the correct sized regulator for your project.
Propane fire pits require a pressure between 7” WC and 11” WC. If your flame height is low you likely have a grill regulator. Upgrade to a high-pressure regulator to fix the flame height.
Options for Connecting to Your Propane Tank
There are two common ways to control the flame height; with a key valve or with an adjustable regulator. If you want a basic installation where you control the flame at the propane tank, you can install a high-pressure adjustable regulator which goes from 0 to 20 psi. This is the quickest and easiest installation.
If you want to control the flame without having to open the cabinet and access the propane tank, you can install a “key valve.” A key valve is a gas ball valve which comes with a key to turn the valve on and off and to adjust the flame height. Key valves are installed in the wall of your structure for easy access. We recommend that you purchase a connection kit which includes the key valve, regulator, air mixer and hoses. This will provide everything you need to connect your burner to the propane tank.
If you’re installing a CSA-certified burner kit, you don’t need to purchase anything to connect it to your propane tank. Everything is included—the regulator, air mixer, spark igniter, thermocouple, control valve and hoses.
CELESTIAL SUPPORT
We’re here to help you with the installation of your Celestial DIY fire pit components. Available by phone M-F, 8:00 AM to 5:00 PM Eastern Time or by email.
(301) 245-7755
Support@CelestialFireGlass.com
