Results 1 to 19 of 19
  1. #1
    Join Date
    Dec 2008
    Location
    Erwin, TN
    Posts
    330

    Default Return vent for HVAC above non vented fireplace

    Would this be ok (return vent in basement den above non vented fireplace) I know the HVAC may not be running when this non vented fireplace is on, but since its non vented the off gases would be in the house anyway? (natural gas non vented fireplace with a central A/C furnace present)

    Similar Threads:
    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images
    Crawl Space Creeper

  2. #2
    Join Date
    Aug 2007
    Location
    Memphis TN.
    Posts
    4,311

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Sam Morris View Post
    Would this be ok (return vent in basement den above non vented fireplace) I know the HVAC may not be running when this non vented fireplace is on, but since its non vented the off gases would be in the house anyway? (natural gas non vented fireplace with a central A/C furnace present)
    Hi Sam,

    As shown not a concern.
    * vented appliance / solid wood or gas would require a10 f00t clearance.

    Last edited by Billy Stephens; 06-07-2013 at 08:37 AM. Reason: FEET TO FOOT
    It Might have Choked Artie But it ain't gone'a choke Stymie! Our Gang " The Pooch " (1932)
    Billy J. Stephens HI Service Memphis TN.

  3. #3
    Join Date
    Jul 2010
    Location
    Wisconsin
    Posts
    274

    Default Re: Return vent for HVAC above non vented fireplace

    A non-vented gas fireplace is allowed in your area?


  4. #4
    Join Date
    Dec 2008
    Location
    Erwin, TN
    Posts
    330

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Mike Kleisch View Post
    A non-vented gas fireplace is allowed in your area?
    Yes, sure has


  5. #5
    Tabb Jensen's Avatar
    Tabb Jensen Guest

    Default Re: Return vent for HVAC above non vented fireplace

    The heat/gasses will rise into your return. Problem when running both. Non-vented natural gas fireplaces scare me. My spider senses tingle when I get near them. My neighbor nearly killed himself with a kerosene heater. My belief is that they should be vented as a furnace or a water heater is. But - they say different. It's your air too breathe. Good luck.


  6. #6
    Join Date
    Feb 2008
    Location
    New York
    Posts
    869

    Default Re: Return vent for HVAC above non vented fireplace

    I am not familiar with your local codes and do not wish to debate legal or not legal. Having said that; there is nothing good about that installation.

    The combustion gasses are being distributed via the duct system throughout the entire home.

    Steven Turetsky, UID #16000002314
    homeinspectionsnewyork.com
    eifsinspectionsnewyork.com

  7. #7
    Join Date
    Aug 2007
    Location
    Memphis TN.
    Posts
    4,311

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Steven Turetsky View Post
    I am not familiar with your local codes and do not wish to debate legal or not legal. Having said that; there is nothing good about that installation.

    The combustion gasses are being distributed via the duct system throughout the entire home.
    Your right Steve as with any vent less gas appliance ( return vent or not )

    It Might have Choked Artie But it ain't gone'a choke Stymie! Our Gang " The Pooch " (1932)
    Billy J. Stephens HI Service Memphis TN.

  8. #8
    Join Date
    Feb 2008
    Location
    Chicago IL
    Posts
    2,048

    Default Re: Return vent for HVAC above non vented fireplace

    Its winter, its cold, the house is buttoned up, you have a nice romantic evening on the bearskin rug in front of the vent gas fireplace, forget to turn it off when you leave the room, furnace runs through the night sucking the gas ventless fireplace fumes up into the return, distributes them throughout the house ... you don't wake up in the morning.
    As I tell all my clients, use it as decoration or throw it in the alley.

    www.aic-chicago.com
    773/844-4AIC
    "The Code is not a ceiling to reach but a floor to work up from"

  9. #9
    Join Date
    Apr 2013
    Location
    pennsylvania
    Posts
    2

    Default Re: Return vent for HVAC above non vented fireplace

    A non vented gas appliance still emits CO ..nonvented appliances always need a fresh air make up close by if not the quality of the air deteriorates.

    - - - Updated - - -

    A non vented gas appliance still emits CO ..nonvented appliances always need a fresh air make up close by if not the quality of the air deteriorates.


  10. #10
    Ben Tressel's Avatar
    Ben Tressel Guest

    Default Re: Return vent for HVAC above non vented fireplace

    Here in the Pacific Northwest, not only do we need to vent all combustion appliances but we have to do detailed pressure testing to make sure those appliances do not back-draft when exhaust fans and HVAC is on. An unvented gas fireplace would be red tagged by the local gas utility without question. This home needs carbon monoxide alarms everywhere. I would put one on by the fireplace, each level of the home, by the bedrooms and by a furnace supply vent. I personally like the alarms/monitors that have a digital read out of the PPM because you now exactly what the concentration is and many also keep a memory of readings in case no one is home when the problem arises.


  11. #11
    Join Date
    Aug 2007
    Location
    Memphis TN.
    Posts
    4,311

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Ben Tressel View Post
    Here in the Pacific Northwest, not only do we need to vent all combustion appliances but we have to do detailed pressure testing to make sure those appliances do not back-draft when exhaust fans and HVAC is on. An unvented gas fireplace would be red tagged by the local gas utility without question. This home needs carbon monoxide alarms everywhere. I would put one on by the fireplace, each level of the home, by the bedrooms and by a furnace supply vent. I personally like the alarms/monitors that have a digital read out of the PPM because you now exactly what the concentration is and many also keep a memory of readings in case no one is home when the problem arises.
    So you need to vent all ( even those Manufactured as Vent less ) gas appliances ?

    It Might have Choked Artie But it ain't gone'a choke Stymie! Our Gang " The Pooch " (1932)
    Billy J. Stephens HI Service Memphis TN.

  12. #12
    Ben Tressel's Avatar
    Ben Tressel Guest

    Default Re: Return vent for HVAC above non vented fireplace

    The only natural gas combustion appliance that gets a pass in existing construction is a gas oven/stove. In new construction, a oven hood which vents to the exterior is required. It is an absolute rule that if elevated carbon monoxide is present in the home, no weatherization may happen until that problem is fixed. The major push here is to tighten homes as much as possible, so we definitely do not want a heating source spilling CO. If I saw this in a home, it would be a huge red flag. Honestly, I would walk away from the job if the homeowner didn't agree to get rid of it.


  13. #13
    Join Date
    Aug 2007
    Location
    Memphis TN.
    Posts
    4,311

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Ben Tressel View Post
    The only natural gas combustion appliance that gets a pass in existing construction is a gas oven/stove. In new construction, a oven hood which vents to the exterior is required. It is an absolute rule that if elevated carbon monoxide is present in the home, no weatherization may happen until that problem is fixed. The major push here is to tighten homes as much as possible, so we definitely do not want a heating source spilling CO. If I saw this in a home, it would be a huge red flag. Honestly, I would walk away from the job if the homeowner didn't agree to get rid of it.
    Ben,

    I agree that a gas appliance used as a "Heating Source " needs to be vented.
    *what is being discussed is a not a Heat Source but a decorative appliance.
    ** if not used per the Manufactures Instructions could be hazardous.
    http://literature.mhsc.com/majestic/...6_33ISDG_4.pdf

    It Might have Choked Artie But it ain't gone'a choke Stymie! Our Gang " The Pooch " (1932)
    Billy J. Stephens HI Service Memphis TN.

  14. #14
    Ben Tressel's Avatar
    Ben Tressel Guest

    Default Re: Return vent for HVAC above non vented fireplace

    thanks for the clarification Billy. I guess it doesn't seem so crazy now. Still a bad idea tho.


  15. #15
    Join Date
    Aug 2007
    Location
    Memphis TN.
    Posts
    4,311

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Ben Tressel View Post
    thanks for the clarification Billy. I guess it doesn't seem so crazy now. Still a bad idea tho.
    Yeah,

    Kinda like Drive-thru Liquor Stores.
    *but what ya gonna do.

    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images
    It Might have Choked Artie But it ain't gone'a choke Stymie! Our Gang " The Pooch " (1932)
    Billy J. Stephens HI Service Memphis TN.

  16. #16
    Join Date
    Feb 2008
    Location
    New York
    Posts
    869

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Billy Stephens View Post
    Ben,

    I agree that a gas appliance used as a "Heating Source " needs to be vented.
    *what is being discussed is a not a Heat Source but a decorative appliance.
    ** if not used per the Manufactures Instructions could be hazardous.
    http://literature.mhsc.com/majestic/...6_33ISDG_4.pdf
    Billy, I don't quite get the gist of your post. Maybe I am misunderstanding you. What is the difference if it is being used as a heating source or as a decorative appliance? if it is burning it is emitting CO.

    Steven Turetsky, UID #16000002314
    homeinspectionsnewyork.com
    eifsinspectionsnewyork.com

  17. #17
    Join Date
    Aug 2007
    Location
    Memphis TN.
    Posts
    4,311

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Steven Turetsky View Post
    Billy, I don't quite get the gist of your post. Maybe I am misunderstanding you. What is the difference if it is being used as a heating source or as a decorative appliance? if it is burning it is emitting CO.
    Volume.

    Anything that burns emits harmful by products. Cigars, Candles, Fondue, Frying an egg cooking or baking in a Gas Stove.

    * decorative use ( ambiance ) for short periods of time not installed in a bath or bedroom with amble makeup air per the Manufactures instructions.

    **Primary or supplemental heat source without makeup air ( using the appliance outside its listing ) very hazardous.

    It Might have Choked Artie But it ain't gone'a choke Stymie! Our Gang " The Pooch " (1932)
    Billy J. Stephens HI Service Memphis TN.

  18. #18
    Join Date
    Mar 2007
    Location
    Fletcher, NC
    Posts
    28,032

    Default Re: Return vent for HVAC above non vented fireplace

    Quote Originally Posted by Steven Turetsky View Post
    Billy, I don't quite get the gist of your post. Maybe I am misunderstanding you. What is the difference if it is being used as a heating source or as a decorative appliance? if it is burning it is emitting CO.
    Used as a heating source - you go to sleep and 'wake up dead'.

    Used as a decorative appliance - you turn it off before going to sleep (theoretically, anyway).

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  19. #19
    Join Date
    Mar 2007
    Location
    Near Philly, Pa.
    Posts
    1,682

    Cool CO alarms vs monitors

    A gas oven is allowed by ANSI to emit 800ppm CO AF because it's use is usually (love that part) limited to once or twice a day at a max. of about 3-4 hrs. per use. Therefore, IF....your home has the min. 0.35 ACH then theoretically, the ambient CO levels would remain under actionable levels............according to the great minds of the world. BTW, a ventfree appliance can emit 200ppm. And you thought it was the L-tryptophan from the turkey making you sleepy at Thanksgiving. Put a pot of cold water on a gas range, fire it and read the ambient CO. Now, crack the oven door, set it to "broil" and read the ambient CO. Be ready to remove your sensor before it pegs too high. Now, line the oven bottom with tin foil and repeat.

    As for what alert device to recommend, understand the shortcomings of the UL 2034 listing for CO alarms:
    You can breathe 69ppm for up to 30 days or 70ppm up to 4hrs. before a listed alarm is *supposed* to alert. I say supposed because they have a terrible track record of failure to alert at required levels or even at all. Now, for the fun part- the UL listing is based upon alerting only once a person in that space breathing the air achieves a carboxyhemoglobin level of >5%. Great! It alerts to wake me just before I pass out and die to warn me to escape. These alarms are NOT designed to protect against CO poisoning! They are designed to protect against CO death! To that end, they often fail miserably.

    Do yourself a favor and get unlisted CO monitors that alert at 15ppm after 60 seconds, are very reliable, don't alert false positives, and are very accurate.

    Keep the fire in the fireplace.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •