Go Back   InterNACHI Inspection Forum > Specific Inspection Topics > Inspecting HVAC Systems

Notices

Inspecting HVAC Systems Topics include heating, venting, and air conditioning inspections.

Reply
 
LinkBack Thread Tools
  #1  
Old 4/14/06, 6:16 PM
scosta's Avatar
scosta scosta is offline
Active Poster
 
Join Date: Oct 2005
Location: North Royalton, Oh
Posts: 186
Please Note: scosta is a non-member guest and is in no way affiliated with InterNACHI or its members.
Default Direct vent fireplace fogged glass

What do you think is causing the inside of the glass on this direct vent fireplace to fog? Poor venting? Pilot was lit, it vents directly out the back to the exterior.

Thanks, Steve
Attached Thumbnails
direct-vent-fireplace-fogged-glass-fireplace-fog.jpg  
Reply With Quote
  #2  
Old 4/14/06, 6:28 PM
Larry Kage, CMI Larry Kage, CMI is offline
InterNACHI Member
 
Join Date: Jul 2004
Location: NW, MI
Posts: 12,086
Default Re: Direct vent fireplace fogged glass

Water is in gas. The condensation is a by product of combustion. It will probably disappear when the burner is ignited.

Did you try the burner?
Reply With Quote
  #3  
Old 4/14/06, 6:31 PM
scosta's Avatar
scosta scosta is offline
Active Poster
 
Join Date: Oct 2005
Location: North Royalton, Oh
Posts: 186
Please Note: scosta is a non-member guest and is in no way affiliated with InterNACHI or its members.
Default Re: Direct vent fireplace fogged glass

Yes, and it fired up. I did not run it long though. Were you gonna say after leaving it run a while the fog would go away?

Thanks, Steve
Reply With Quote
  #4  
Old 4/14/06, 7:13 PM
Larry Kage, CMI Larry Kage, CMI is offline
InterNACHI Member
 
Join Date: Jul 2004
Location: NW, MI
Posts: 12,086
Default Re: Direct vent fireplace fogged glass

Yes, once the fireplace heats up the moisture should go away.
Reply With Quote
  #5  
Old 4/15/06, 3:19 AM
Russel Ray's Avatar
Russel Ray Russel Ray is offline
InterNACHI Member
 
Join Date: Mar 2003
Location: La Mesa, CA
Posts: 17,446
Default Re: Direct vent fireplace fogged glass

It's more than moisture.

Be right back with great info for you.



NACHI 2005 U.S. Member of the Year
Reply With Quote
  #6  
Old 4/15/06, 3:22 AM
Russel Ray's Avatar
Russel Ray Russel Ray is offline
InterNACHI Member
 
Join Date: Mar 2003
Location: La Mesa, CA
Posts: 17,446
Default Re: Direct vent fireplace fogged glass

Here you go:

Quote:
White film on glass panels. According to Mr. Dale W. Feb, Executive Director of the Fireplace Investigation, Research, and Education Service (Moorpark, California), the white film is sulfuric acid. All fossil fuel produces sulfur during the combustion process, and when this sulfur is mixed with moisture, sulfuric acid is created. The white film (acid) may permanently etch the glass and should be removed on a regular basis. Permanent damage might already have occurred to the glass panels and replacement may be necessary. Recommend further evaluation by licensed fireplace professional. Information obtained from http://inspectionnews.com/ubb/Forum7/HTML/000129.html.
There's also a picture in the very first post in that thread.

Sometimes the link doesn't work; tonight it did.



NACHI 2005 U.S. Member of the Year
Reply With Quote
  #7  
Old 4/15/06, 7:13 AM
Larry Kage, CMI Larry Kage, CMI is offline
InterNACHI Member
 
Join Date: Jul 2004
Location: NW, MI
Posts: 12,086
Default Re: Direct vent fireplace fogged glass

Quote:
Originally Posted by rray
It's more than moisture.

Be right back with great info for you.
Yes, good info Russel. It may be that, however I've noted many fireplace glass fronts that cleared, what appeared to be moisture, after it was heated up. These were all pilot lighted units I'm talking about. I had one for years that acted that way and never damaged the glass. It always cleared.
Reply With Quote
  #8  
Old 4/15/06, 11:46 AM
Russel Ray's Avatar
Russel Ray Russel Ray is offline
InterNACHI Member
 
Join Date: Mar 2003
Location: La Mesa, CA
Posts: 17,446
Default Re: Direct vent fireplace fogged glass

They do clear up. I've never seen one that didn't clear up. However, the damage from the sulfuric acid remains, even though it might, indeed, take years before the damage is noticeable. It depends on the quality of the gas and how often the fireplace is used.

I had a one-year-old house a couple of weeks ago that had a direct vent fireplace. When I flipped on the switch, the glass fogged up and the Client got upset. We let it burn awhile and I showed her the damage that had already been caused by the sulfuric acid. They have requested from the seller a new glass front for the fireplace. Our gas out here is pretty oogy.



NACHI 2005 U.S. Member of the Year
Reply With Quote
  #9  
Old 4/15/06, 12:13 PM
Larry Kage, CMI Larry Kage, CMI is offline
InterNACHI Member
 
Join Date: Jul 2004
Location: NW, MI
Posts: 12,086
Default Re: Direct vent fireplace fogged glass

Quote:
Originally Posted by rray
It depends on the quality of the gas and how often the fireplace is used.
Yes, that may be it.


Quote:
Originally Posted by rray
Our gas out here is pretty oogy.
I've heard that about more things than gas in CA.
Reply With Quote
  #10  
Old 4/15/06, 12:28 PM
Russel Ray's Avatar
Russel Ray Russel Ray is offline
InterNACHI Member
 
Join Date: Mar 2003
Location: La Mesa, CA
Posts: 17,446
Default Re: Direct vent fireplace fogged glass

By the way, if anyone ever has an opportunity to attend a seminar by Dale Feb, one should jump at the opportunity. One will never look at, or think about, fireplaces and chimneys the same way again. They are eye-opening seminars.



NACHI 2005 U.S. Member of the Year
Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Direct Vent Fireplace jhagarty Inspecting HVAC Systems 8 6/23/07 9:55 AM
Gas and oil hot water tank and Boiler Share Vents hvanderbeek Miscellaneous Discussion for Inspectors 8 1/25/07 5:22 PM
Fireplace / Direct Vent problem srowe Inspecting HVAC Systems 5 2/16/06 1:57 PM

All times are GMT -4. The time now is 3:37 AM.
no new posts