I think you will usually find they are called either power vent or closed combustion units. The power vent type uses a fan to exhaust gasses, will draw combustion air from the building while the closed combustion units have two vents through the wall, one for exhaust and the other for combustion air. These then don't burn already heated air and they will often pull the exhaust gasses back down through the combustion chamber and on around to extract more heat from them. Some end up exhausting mildly warm moist gas having recovered over 90% of the heat energy from the fuel.
I believe some of the newest models have two pipes one inside the other, I do know that some of the water heaters do and expect that the fire places do as well. I am not aware of wood heating appliances with through-the-wall exhaust but it is possible. The big problem would be extinguishing the fuel in the case of a ventilation failure. Gas can be turned off but not so a burning log. Some genius though may have solved this. Dale Leavens, Cochrane Ontario Canada [EMAIL PROTECTED] Skype DaleLeavens Come and meet Aurora, Nakita and Nanook at our polar bear habitat. ----- Original Message ----- From: "Dan Rossi" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, November 30, 2006 10:11 PM Subject: Re: [BlindHandyMan] outdoor fireplaces >I believe there are such animals as ventless gas fireplaces now. I don't > know if they are called ventless because they need no chimney but have an > external horizontal vent, but that is my understanding at least. > > -- > Blue skies. > Dan Rossi > Carnegie Mellon University. > E-Mail: [EMAIL PROTECTED] > Tel: (412) 268-9081 > > > To listen to the show archives go to link > http://acbradio.org/handyman.html > or > ftp://ftp.acbradio.org/acbradio-archives/handyman/ > > The Pod Cast address for the Blind Handy Man Show is. > http://www.acbradio.org/news/xml/podcast.php?pgm=saturday > > The Pod Cast address for the Cooking In The Dark Show is. > http://www.gcast.com/u/cookingindark/main.xml > > Visit The New Blind Handy Man Files Page To Review Contributions From > Various List Members At The Following Address: > http://www.jaws-users.com/handyman/ > Visit the new archives page at the following address > http://www.mail-archive.com/[email protected]/ > For a complete list of email commands pertaining to the Blind Handy Man > list just send a blank message to: > [EMAIL PROTECTED] > Yahoo! Groups Links > > > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.409 / Virus Database: 268.15.0/557 - Release Date: 29/11/2006 > > To listen to the show archives go to link http://acbradio.org/handyman.html or ftp://ftp.acbradio.org/acbradio-archives/handyman/ The Pod Cast address for the Blind Handy Man Show is. http://www.acbradio.org/news/xml/podcast.php?pgm=saturday The Pod Cast address for the Cooking In The Dark Show is. http://www.gcast.com/u/cookingindark/main.xml Visit The New Blind Handy Man Files Page To Review Contributions From Various List Members At The Following Address: http://www.jaws-users.com/handyman/ Visit the new archives page at the following address http://www.mail-archive.com/[email protected]/ For a complete list of email commands pertaining to the Blind Handy Man list just send a blank message to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/blindhandyman/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/blindhandyman/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
