DVC-500 Owners - Chimney Advise

I'm back.. for more advise !

Today I was told by an "authority" on town codes that the 3 foot "chimney" that the DVC-500 uses is not legal according to my town code. The reason is that it has to terminate above any and all structure openings like doors and windows. The Harman manual does offer a few tips for installation that includes a comment "Will exhaust be vented where fumes can build up or be drawn into lower levels of the structure"

As you see, my stack in under a large wall air conditioner that is off of course when the stove is on and covered on the inside. I have a sliding glass door to the right and a bathroom window to the right.

Regardless of whether town code exists, I'd have to agree with the principal. I can leave the window and door closed of course but IF I wanted to take action, I could run this single wall galvanized pipe up, around the air conditioner and straight up two stories above the roof line. Will that still work or is that way to much uninsulated pipe to force the exhaust up?

**Broken Image Link(s) Removed**

Well I don't know what others think but to me it just looks like you upgraded to a propane or gas fired dryer and had to run it through a different hole than the original dryer to the left *wink wink nudge nudge*

right
but now I'm panicking! Very often the room where the stove is located gets too hot so we open the door which is less than 5 feet from the exhaust. Am I sucking hot exhaust INTO the house? We don't smell anything and the CO sensors are not going off. I am trying to figure out if extending the pipe 16-20' will be a problem?

thx

Yikes...yeah that would worry me as well. I wish I had an answer for you...the problem with the DVC-500 is that it is specifically engineered to be direct vent...it was not designed with any sort of chimney in mind. Even if pushing the gas out with a taller setup was ok (I'm not sure if the exhaust side on a DVC is hot enough for the height mentioned) it still may not run correctly because you might be looking at a situation where you have created a natural draft with that kind of height. The other problem is that your incoming air is inside of that pipe. The possible creation of a draft may end up starving the fire of air....you might end up having the combustion blower fighting a newly created draft on the intake side. The likelyhood that you are litterally sucking exhaust into the house is not that great if the Harman is the only heating appliance currently running....all of it's air is brought in through that pipe within a pipe setup....so there should not be negative house pressure created by the stove unlike most other setups. However if you had a regular furnace running at the same time as the DVC then it would be possible with that door open. (obviously it is not likely you would have the door open and running your nomal furnace at the same time) I wish there was a simple answer I had. I would certainly start by keeping that door closed to be safe...

Can you check with yourt authority about what the codes are regarding direct vent gas appliances (such as the Rannai's ect).....that vent in NOT a chimney...that is direct vent,postive air pressure unit you have....not a chimney. I'm sure there are plenty of people in your town with high efficiency gas boilers that direct vent....this stove should not be treated any differently. It does not createnegative house pressure and therefore does not create the chance of exhaust being sucked into the house near the unit. The exhaust is positive pressure and does not rely on natural draft at all.
The combustion air is all brought in from the outside,fresh air intake.

NEPANewb wrote:Yikes...yeah that would worry me as well. .........

Excellent reply. Thank you. I'm going to check with the town but no matter, the Harman manual states the 5' distance from a door and I am closer. Even of there is no town issue I am still concerned. I bought a CO sensor with a digital readout, very intresting:
- no reading at all in the house
- no reading near the stove
- door open, no wind and no reading near the door
- brought the unit outside, stuck it just under the exhaust, ramped up to 404 ppm fairly quickly but no alarm. Manual says a min of 400+ppm for 4 min is required to set it off.

For now, we keep the door closed anyway. I'm calling my dealer and Harman for advise on the chimney.

Again, appreciate your feedback. thx

Have a dvc also. Keep your window and door closed it is no problem at all.
Nothing to worry about. I have a similiar situation.

TCOAL wrote:Have a dvc also. Keep your window and door closed it is no problem at all.
Nothing to worry about. I have a similar situation.

Thanks. Whats happening is the room where the stove is located gets way too hot while the rest of the house is perfect. I'm going to look into a ceiling fan as the door needs to remain shut for sure.

As a slightly different option...Harman DOES have extention pieces of the square pipe for people who want to install the DVC in a basement....perhaps there could be some way to make that work in your instance? I know it would require redoing your installation a bit...but it would certainly take care of the possible building code issue...I think you said that the termination has to be above any window or door...is that room a single story area of the house? If that is the case then you would have to run the extention pipe up the wall inside and go out near the ceiling or figure out a way to run that extention up on the outside...but staying within Harman's specs. I would certainly try to see if the code applys in your instance 1st though

Pickup a couple room fans in the mean time and aim them at a 45degree angle at the ceiling but in the direction of the rest of the house to try and get some of that heat out of there. One of the semi industrial floor level fans or even better a vornado would do a good job...even running on low. If you want to get fancy you could setup a cold air return plumed to the distrbution blower from the far end of the house....this could work if you have a basement below the stove and it would literally pull the warm air through the house....similar to how a furnace works in distributiing heat evenly.

Once you get this all figured out I might just have to stop by over the holidays to see the final product haha....(the wife is from Sayville and we typically packup the family and spend a few days over Xmas to visit the inlaws)

Good luck

NEPANewb wrote:As a slightly different option...Harman DOES have extention pieces of the square pipe for people who want to install the DVC in a basement....perhaps there could be some way to make that work in your instance? I know it would require redoing your installation a bit...but it would certainly take care of the possible building code issue...I think you said that the termination has to be above any window or door...is that room a single story area of the house? If that is the case then you would have to run the extention pipe up the wall inside and go out near the ceiling or figure out a way to run that extention up on the outside...but staying within Harman's specs. I would certainly try to see if the code applys in your instance 1st though

Pickup a couple room fans in the mean time and aim them at a 45degree angle at the ceiling but in the direction of the rest of the house to try and get some of that heat out of there. One of the semi industrial floor level fans or even better a vornado would do a good job...even running on low. If you want to get fancy you could setup a cold air return plumed to the distrbution blower from the far end of the house....this could work if you have a basement below the stove and it would literally pull the warm air through the house....similar to how a furnace works in distributiing heat evenly.

Once you get this all figured out I might just have to stop by over the holidays to see the final product haha....(the wife is from Sayville and we typically packup the family and spend a few days over Xmas to visit the inlaws)

Good luck

Yes, Ive seen the Harman square extension pipe for basement installs. Discussing possible usage in my application will be discussed with my dealer. I have a two story house, I suspect code would want it above the second story. I'm less worried about town code as I am family safety. Door closed and a floor standing Vornado (good idea) is my immediate plan. I'm 5 min from Sayville, come by with a couple of bags of clean rice and your welcome!

Those extensions get pretty pricey. I'm putting one in my basement, I went up about 7 feet and I think it cost me a couple hundred bucks for the vent pipe, and you have to order it from Harman it might take awhile, I'm still waiting on a 45 degree piece that I ordered 3 months ago, just FYI.