For Best Price
Call: 1-800-201-1193
 
Products Navigation Menu Ceiling Fans Guaranteed Lowest Prices All types of Lighting for your home Fireplace Gas Logs Fireplace decor, screens and accessories Firemagic Barbecues Furniture and Decor
Hansen Wholesale on Facebook Hansen Wholesale on Twitter Now accepting PayPal
NEW Eco Fans!The Most Efficient Ceiling Fans
Tell us your Ceiling Fan ideas!
Bookmark this page!

Why Do Ventless Gas Logs Smell?
A discussion about the odor produced by burning vent free gas logs.

December 14, 2009
By: Greg Tillotson
Gas Log Expert & Webmaster for Hansen Wholesale


Similar Pages: Gas Log FAQs page! Vented vs VentFree Gas Logs

We have so many visitors reach our site that already own ventless gas logs and are asking why they produce a smell, how to get rid of the smell or other similar questions. Not only is this page meant to answer that question, but to provide valuable insight to those who are considering purchasing vent free gas logs now or in the future.

Keep in mind that this discussion DOES NOT apply to Vented Gas Logs. Vented gas logs are burned in wood burning fireplaces with the damper fully open, so the smell that is produced goes up the fllue. So unless you have a poorly drafting fireplace, you will not have the odor problem described below if you install vented gas logs.

So...on with the details!

For the sake of this discussion, I will be referring to Natural Gas. Although Liquid Propane and the additives used in its production have a different chemical makeup than Natural Gas, the basic premise below applies to both gases.

Ventless logs do in fact produce an unmistakeable odor. There is no way of preventing this, it is simply the nature of burning natural gas in your home without exhausting the fumes up a chimney. In a perfect world, the natural byproduct of burning "pure" natural gas is water vapor and carbon dioxide, and many people believe that burning natural gas in your home should produce no odor...so they think there is something awry with their ventless logs when they produce a smell.

The chemical formula that describes the combustion of Methane Gas (natural gas in it's purest form) shows how Methane gas is made up of Carbon and Hydrogen molecules. When burned, the Carbon combines with Oxygen producing carbon dioxide and the Hydrogen combines with Oxygen to produce Water Vapor. Both of which are odorless non-toxic gases. If the gas does not burn completely, then some of the carbon molecules remain as carbon (soot) and some of them combine with a single oxygen molecule and produce Carbon Monoxide (which is still an odorless gas). The final byproduct of the reaction is the production of heat (-890 kJ/mol). Here's the formula:

CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) -890 kJ/mol

Side note: If you see soot accumulating on your logs, then you can assume that carbon monoxide is also being produced.

Unfortunately, we do not live in a perfect world and the natural gas that is supplied to your home is not perfect. It contains small amounts of impurities and additives, one of which is the rotten egg smell which is added so that you can smell a gas leak if it occurs (again, natural gas in its raw state is odorless). The most common rotten smelling additive is Methyl Mercaptan. The byproduct of burning Mercaptan is Sulfur Dioxide, which smells more like burnt matches mixed with rotten eggs. Include other odors produced by impurities in the gas supply and you have the distinct smell ventless logs produce.

Furthermore, Sulfur dioxide is an irritant to the eyes and respiratory tract in a more concentrated amounts. Although, gas suppliers claim that the amount of Mercaptan added to natural gas is so minute that it poses no health risk, many people do experience discomfort when burning ventless logs...particularly eye irritation or coughing spells.

What can you do if you have vent free logs and simply cannot live with the odor?

  1. Do not burn your ventless gas logs...or
  2. Open the damper in your fireplace (if you have a fireplace with a chimney...and/or
  3. Open some windows (and let fresh cold air in while you are trying to warm your house)...and/or
  4. Replace your ventless log set with a vented one designed to be burned with the damper fully open.

Bottom Line: We highly recommend that you purchase vented gas logs. You will be much happier with flame that they produce and less likely to experience discomfort from odors or irritation. We only recommend ventless logs when maximizing the heat output outweighs all of the other negative aspects.


Related Articles:
Have a Question About? Ask an Expert!

Talk To A Live Expert!
Call: 1-800-201-1193

or...Ask Your Questions Here!
(500 characters max)

*Name: 
*Email:  
Phone:  
Your information is kept private. Leave your phone# if you wish to speak directly to an expert (recommended)!

(We only respond to questions about brands that we sell)

Answers to Recent Gas Logs Questions Posted To This Page
  1. Question #9479 - Posted: 4/8/2014 1:36:59 AM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/vented/model.asp?StyleCode=RDP&FPType=Standard&GasType=NG&Na...

    QUESTION: I am looking for Peterson Model # SDPG46-18-17, but I do not see it on your web site. Do you carry it?

    ANSWER: Yes, we do carry it. Here is a link: Peterson SDPG46-18-17 Split Oak Designer Plus

  2. Question #9475 - Posted: 4/8/2014 1:29:42 AM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/default.asp

    QUESTION: On a RH Peterson burner, what is the difference, or pros and cons from a G45A Burner and a G45 Triple T Burner? Is it just the certification or is there a performance difference as well?

    ANSWER: The G45A has a manual safety pilot that is factory installed and tested to meet ANSI approval. The G45 is a match-light burner with no safety pilot. If you purchase a G45 and add a safety pilot it will not be installed and tested at the factory. Otherwise, both burners are identical and both are Triple T. Many cities and states require ANSI approval, so if in doubt, it is best to purchase an ANSI approved burner.

  3. Question #9474 - Posted: 4/7/2014 1:30:01 AM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/model.asp?SetModel=PL-CHASG10-16&FRONTWIDTH=32&BACKWIDTH=20&...

    QUESTION: I have a zero clearance fire place that had the chimney removed when the house was re-roofed. I never intend to burn wood in it again. It never worked very well burning wood. Ventless is an option, but what are my options for a vented log? I would not want to take the vent through the roof. Can it be vented to a side wall? What are the limitations for running vent horizontally (how long)? I live in St. Louis, MO. Firebox can handle a G10 18

    ANSWER: There are no options to vent a previous wood burning fireplace out a side wall, it must be vented through the roof as it was before in order to burn any gas logs, vented or ventless. Please do not burn anything in your fireplace without having he chimney installed as it was before...it will not be safe.

  4. Question #9467 - Posted: 4/3/2014 7:53:00 AM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/installers.asp

    QUESTION: I am looking at model HRG45-24-P-SS. the gas line comes into the fireplace from the left side (looking forward at the fireplace). Will this burner-log set work? When I looked at the instruction manual, the diagram shows the gas line on the right.

    ANSWER: You can easily reroute the gas line to the left side using a longer flex tube or black pipe. Often times, depending on the location of your gas line, the flex tube that comes with the burner will reach the other side. If it does not, then you can purchase a longer flex tube from us or from a hardware store or home center.

  5. Question #9455 - Posted: 2/17/2014 9:10:47 AM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/vented/24-inch.asp

    QUESTION: Cn I just order the burner since I already have a 24 " split oak log set? My existing burner is leaking. Am looking at the G46-24 SPK.

    ANSWER: Yes, if you already have Peterson logs, we can supply you with the correct burner that is matched to them. The G46-24-SPK is one of the burners that is compatible with your logs. Give us a call and we will process your order over the phone. Call: 1-800-201-1193.

  6. Question #9454 - Posted: 2/17/2014 9:09:00 AM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/why-ventless-gaslogs-smell.asp

    QUESTION: Hello, Thank you for taking my question. We have install installed a ventless fire place Patterson.. The unit was complete but had no logs supplied. Bought new logs. Can any ventless log be used with the burner. Or are the logs and burner sold only in sets?

    ANSWER: Warning: Do not use any logs other than those designed for the particular burner you own. The logs are in fact specific to the burner. It is critical that you get the right logs because if the flame hits the logs differently than the original design it can cause the gas to burn incompletely. Incomplete combustion of gas results in the additional byproducts of soot and carbon monoxide (lethal and odorless), which will be introduced directly into your home.

  7. Question #9449 - Posted: 2/1/2014 3:26:13 PM

    Gas Logs Question

    http://www.hansenwholesale.com/answers.asp?ProdType=LOGS

    QUESTION: I have a Peterson 18" gas log set I'm installing myself. The installation manual shows a right hand gas supply. My fireplace has a left gas supply. Can I just disassemble the burner pan and convert it to a left gas input and put the cap on the right? Or do I need to run a lot more pipe all the way from the left side to the right side? Thanks

    ANSWER: If you have a matchlight system (one without a safety pilot) then you can switch the plug and orifice from one side to the other to convert it to left gas input. If you have a safety pilot, it depends on the pilot system you have: some of them can and other cannot be reversed...it will be obvious because the pilot mechanism would be upside down when reversed. If such is the case, then either get a longer flex tube from a home center, or reroute the gas line using black pipe and elbows.

  8. Question #9448 - Posted: 1/30/2014 9:12:57 AM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/why-ventless-gaslogs-smell.asp

    QUESTION: We have a "Fire-Gear" vent-less propane fireplace. It gives off a noxious odor. We had it service but to no avail. We are thinking of replacing it w Peterson brand. Will this take care of our problem?

    ANSWER: Fire Gear is not a top quality brand like Peterson, so it is quite likely that replacing them with a better quality vent free gas log from Peterson will help reduce the odor. But it is important to be aware that ALL ventless appliances produce some odor because all of the byproducts of burning the fire are introduced into the room. Propane can be particularly worse than natural gas because the quality of the propane varies from supplier to supplier. The more impurities there are in the propane, the more potential there is for smell coming from burning a ventless gas log. Although we would love to sell you a new gas log set, we cannot guarantee that it would eliminate or reduce the odor. The only way to find out would be to install them. At least in that manner, you would know for sure whether it is the log set causing the problem, or the gas you are being supplied. Read more about what causes vent-free gas logs to produce a smell:

  9. Question #9447 - Posted: 1/30/2014 8:46:17 AM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/vented-vs-ventfree.asp

    QUESTION: My daughter has vented gas logs in her bedroom which is about 24x36. It is her primary heat system. Recently we noticed that the ceiling and top part of her walls were becoming covered in black soot. Why would the logs start this and is it dangerous to them. They have a 1 month old that sleeps in that room as well. I have noticed that some of the baby toys that are plastic have the black on them also. I am very nervous about this. Would it be better for them to get ventless with a heatalator?

    ANSWER: Please stop using the gas logs immediately, it is dangerous to use them if they are producing soot. Where there is soot, there is also carbon monoxide, which as you know is a lethal odorless gas. You need to have your gas logs serviced or replaced because they are no longer burning cleanly as vent free gas logs should. Some Heating and AC companies are qualified to service ventless appliances, so use your local yellow pages to call around. Or, you can use the resource on this page to locate a professional who is qualified to service your gas logs: Locate a Gas Log Service Professional.

  10. Question #9446 - Posted: 1/26/2014 3:14:39 PM

    Gas Logs Question

    http://www.hansenwholesale.com/gas-logs/ventless-btu-calculator.asp

    QUESTION: I have a Peterson real fire vented gas log system 18inch in my fireplace for several years and am very satisfied. I would like to change just the burner to make a vent free system for more heat. Is this possible. Thanks

    ANSWER: Unfortunately you cannot change just the burner in order to create a ventless gas log set. The burner and logs must be designed to work together, so you will need to buy a complete setup. The reason is that ventless gas logs must burn in a very controlled manner in order to burn cleanly. Any disruption to the way the flame burns, such as touching the logs in the wrong place, will cause the gas to burn incompletely and produce exhaust...including carbon monoxide and soot. So the flames cannot touch the logs in any manner in which the system was not designed...which means you must have the correct logs and they must be stacked exactly as described in the owners manual.

THE END

R.H. Peterson Gas Logs
(Go to: Gas Log Homepage)
R. H. Peterson Gas Logs Logo

FIREPLACE TYPE
Indoor Outdoor
Natural Gas Propane
Standard See-Thru

What is Standard or SeeThru?

SHOP BY LOG SIZE

Help me choose!


Gas Log Size Calculator

Front Width Back Width Depth
" x " x "
(numbers only round to nearest inch)
Advanced options...
(How do I measure?)
CONTROL TYPE

Help me choose!

HELP
Gas Usage Calculator

Enter the BTU rating of any gas log set to find out how much gas it uses!

BTUs
(number only - no commas)

About this calculator

Gas Log Installation

Locate an Installer

Energy Star Ceiling Fans and Lighting Energy Star Products Energy Star Ceiling Fans Energy Star Lighting
Ceiling Fans - Lighting - Remodeling and Home Design

Consumer Sales
Product Info and Ordering
Phone: 1-800-201-1193
Phone2: 1-562-594-1249 (outside USA)
Fax: 1-562-626-8270
Email: Information Request
Mon-Fri 7am-6pm, Sat 7am-5pm, Sun 8am-6pm (PST)

Customer Service
Questions About Pending Orders
Phone: 1-800-607-2665
Phone2: 1-562-594-1249 (outside USA)
Fax: 1-562-626-8270
Email: Customer Service
Hours: Mon-Fri: 7am-5pm (PST)

Trade/Resale Accounts
Resale, Contractors, Etc.
Phone: 1-800-365-3267
Phone2: 1-562-594-1249 (outside USA)
Fax: 1-562-626-8270
Email: Information Request
Hours: Mon-Fri: 8:30am-4:30pm (PST)

Terms/Conditions/Privacy
About Us
Ceiling Fan Blog

Corporate Mailing Address and Warehouse
Hansen Wholesale 11132 Winners Circle Suite 100, Los Alamitos, CA 90720

Thanks for choosing Hansen Wholesale
Copyright 1994-2014 Hansen Wholesale

The End