Concrete Gas Fire Pits

There are various pros/cons of Liquid Propane (LP) and Natural Gas (NG). The difference between LP and NG Warming Trends burners are the “jets”. If, down the road, you need to convert from LP to NG or vice-versa, you can do so by purchasing replacement jets from us at $25 each. 

Propane – pros

• • Flexibility/portability
  • Opens up new location possibilities
  • Sometimes NG is not available

Propane – cons

• • More expensive to burn than NG
  • Heavier than air, so it sinks down. This makes ventilation more important.
  • Requires refilling the tank
  • Hiding the propane tank can present new aesthetic challenges
  • Black soot tends to build up faster on fire media such as ceramic logs and cannonballs (it can be cleaned off)

Natural Gas – Pros

• • Cheaper to burn; you probably won’t even notice an increase in your gas bill. Clients of ours have reported $0.25 – $0.75 per hour
  • You won’t run out, so burn to your heart’s content without the dreaded “we’re out of gas”
  • Since it’s lighter than air and rises, there’s less likelihood of unwanted fuel accumulation in the vessel
  • Slightly cleaner burning; less soot build up

Natural Gas – Cons

• • Limited to what’s available in your area
  • May require upgraded meter or larger diameter fuel lines to provide adequate BTUs
  • The volume and pressure can be affected by other appliances
  • Might require a longer gas line, depending on where your fire feature will live  
  • Would be difficult to change the fire feature’s location after installation
  • Check the side of your gas meter for a BTU rating. Most commonly they are rated at 250K BTUs

Even though the standard key valve inlet is 3/4″, you may need a larger gas line to span long distances.

In order to get the proper volume and pressure of fuel, you need a gas line that is large enough in diameter to carry it sufficiently. For the most accurate assessment, consult a fuel professional. For a rough estimate, utilize our gas line sizing charts below. 

*Make sure the BTUs from your line can supply at least 60-70% of what the burner is rated at. (At 60% capacity, your flame height may be more like 18″ high vs. 24″+ at full capacity.)

Propane Gas Line Sizing Chart

Natural Gas Line Sizing Chart

Gas line sizing variables

• • Using angled couplings can reduce the volume/flow of fuel
  • Adding a 90 degree angle in your line adds the equivalent of 5 feet of distance
  • Running different sized lines over various distances is acceptable, but for maximum fuel volume, run larger lines over long distances
  • Number of appliances, whether it’s a dedicated line or not; all these factors play a role in volume and pressure
  • Pro Tip: if you haven’t installed your gas line yet, consider running it in conduit so that if you ever need to repair or change it, you won’t have to dig it up

You can have great gas pressure, but if your line is too small, you may not get the desired flame. Think about it like filling up a swimming pool. If you reduce the nozzle size significantly, you may have a ton of pressure, but it’s going to take longer to fill up the pool. You need both pressure and volume to get a great flame. This is why the size of the gas line is so important. 

Now that you understand the importance of volume (BTUs), let’s talk pressure. 

Optimal Pressure for Crossfire burners:

• LP: 11″ water column (w.c.)
• NG: 7″ water column (w.c.)

Water Column is the term used to measure pressure. There are 27.7 inches of water column pressure in 1 PSI of pressure. So 7″wc is about 1/4 PSI. This is the normal pressure that household natural gas is delivered.

The device used to measure pressure of this type is called a Manometer

Pressure too High? You may experience unwanted noise, usually a hissing sound. You might also find it difficult to dial in the desired flame height using the key valve.

Pressure too Low? The flame will not be as tall and hot

Location of Gas Stub

• Most commonly the gas stub is positioned underneath the fire feature so that you don’t see it
• It can be off-center or on-center, depending on the size of your fire feature
• You may want to go off-center if you’re using electronic ignition
• The key valve is generally located on the side of the fire pit, so if it makes sense for your build, place the gas stub off-center to reduce the distance of gas stub to key valve
• Most often, the plumber will use hard pipe to connect from the gas stub to the key valve. However, if they decide to use a flexible line, most lines are 36″ long, so it makes sense to try and keep the gas stub within 36″ from the key valve location
• Instruct the contractor to keep the gas stub as low as possible to make room for electronic ignition, or in the case that the plate sets fairly low
• On some builds, the plate sits only 8″ off the ground

You DO NOT need an air mixer with any of our burners. Air is mixed at each jet. 

LP Regulators

• • For optimal regulation for burners over 250K BTUs, contact a local propane supplier
  • For regulators 250K BTUs or lower, purchase our REGULATOR KIT
  • From the tank, propane is HIGH PRESSURE, so it must be regulated down, because the burners are low pressure
  • For longer gas lines, we often use a high pressure (10psi) regulator at the tank end, and a “2nd stage” regulator on the other end of the line to bring the pressure to 11-13″wc

NG Regulators

• • Consult a professional (plumber/HVAC)

Standard 20lb Tank

• A standard 20lb/5 gallon BBQ propane tank can be used for burner systems 180K BTUs and under
• The Canyonlands Fire Table is a complete unit that can have a self-contained propane tank
• Burn time varies from 6-12 hours, depending on how hot you run it
• Results may vary, and it is common for the fuel to “freeze up” with burners 180K BTUs and up. What that means is that after 45 minutes or so, the flame only goes to about half. Remedy this by using two tanks connected together

40lb Tank

• This is a better option for most of our burners from 100K to 200k BTUs
• It will give you longer burn times
• Still relatively small and easy to move

High Volume Tanks

• Contact your local propane supplier

Hiding the Tank

• You can always run a larger diameter line and hide the tank in an inconspicuous location
• You can purchase 20lb propane tank covers that make hiding the tank a cinch

Gas Consumption

• All of our burners burn with incredible efficiency due to the engineered jets. They mix fuel and oxygen at the flame which makes it taller, brighter, and hotter using less fuel
• Read all about how much fuel you might be burning at full capacity – Learn More

Compliance with the following standards:

• ANSI Z21.97/CSA 2.41 Outdoor Decorative Gas Appliances
• The burner system is certified nationally, however, it is up to the customer or contractor to verify local requirements

Certified Burners

Massachusetts

Effective May 5, 2021 over 100 Warming Trends CROSSFIRE burners will be approved for use in Massachusetts. 

All gas products approved for use can be found on the Massachusetts Consumer Affairs and Business Regulation (OCABR) website: Office of Consumer Affairs and Business Regulation (OCABR). To confirm the approval of a product, simply:

1. Visit the OCABR website.
2. Select “Product Information” from the drop down, then click “Go.”
3. Enter Product information.
   1. Select “Gas” 
   2. Manufacturer: Warming Trends, LLC
   3. Model Number: Enter the burner type and BTU output (i.e. CFB180, CFBT290, CFBO140) If you do not have the model information, you may search using only the manufacturer name to bring up all Warming Trends burners that are accepted. 

Click “Find Products” and see the listing of accepted products. 

Canadian Customers

Most metropolitan areas in Canada will require an automatic shutoff for fire pits over 65K BTUs in order to get a permit or certification.

• Our Premium Electronic Ignition system has the proper fuel and flame censors to automatically shut down the fire when needed. Combine it with a dial timer to increase safety and ease. 
• You can still purchase higher BTU burners without the premium ignition, and we will ship it with a fitting that limits the burner to 65K BTUs in the case that you’d like to have it certified.