1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
  1. ebbtide357

    ebbtide357 New Member

    Joined:
    Oct 15, 2012
    Messages:
    27
    Loc:
    long island new york
    just installed a harman accentra runs great been reading all the forums and decided to put a oak in never got one with the stove wheres a good place to buy one the previous owner had some type of pvc pipe and such but he also gave me the reducer for the oak from 2 1/2 to 2 also what is a zero clearance box?

    Helpful Sponsor Ads!





  2. imacman

    imacman Guest

  3. DAKSY

    DAKSY Patriot Guard Rider Staff Member

    Joined:
    Dec 2, 2008
    Messages:
    5,399
    Loc:
    Averill Park, NY, on Burden Lake II...
    What did you install, an Insert or a Free-Stander? If you have the insert, Harman makes an OAK if you vented it out the wall, if you vented it with a liner up the flue, there are different ways to provide combustion air. If you installed a Free Standing unit, you can get by with a 2" pvc section thru the wall & a 2-3/8" flexible piece of pipe from the pvc to the unit. What part of the country are you located in? There are Harman dealers around if you want the Harman specific parts. The ZC box is for installing the Insert in a framed wall. You do not need it if you're installing the insert in a fire place.
  4. Trickyrick

    Trickyrick Feeling the Heat

    Joined:
    Oct 23, 2009
    Messages:
    282
    Loc:
    Western MA/ Eastern NY
    If you have an insert you NEED the harman OAK. It is a freestanding unit any off the shelf FIRE PROOF OAK will work.

    The zero clearance box is for the insert to be installed into a wall as opposed to a fireplace. It is a simple way to meet the code required (Fireproof box with all clearances) so that you can install your insert like you would a gas fireplace etc. If you are running in a fireplace or have a freesdtanding unit then it is not important...
  5. mtrentw

    mtrentw New Member

    Joined:
    Jan 28, 2013
    Messages:
    3
    I just had a accentra insert installed last week. Had no idea what an OAK was until I read the manual. After some pricing from Harman dealer, I looked at alternatives. A Harman OAK is not required. While it may make things a bit easier, if you have a clean out and enough room behind the frame, a 3" flex metal pipe should work just fine. You need to ensure you have it installed in such a way that sliding the insert in will not be able to pinch it shut. I ended up spending maybe $35 and 2 hours between the fireplace and crawl space.
  6. doublewide

    doublewide Member

    Joined:
    Jun 14, 2010
    Messages:
    119
    Loc:
    Eastern PA
    So is it up to code to use the PVC to go through the wall? Don't say it depends on your municipality because they said they are not going to come out to inspect it. I'm trying to do it up to code but it is easier to put the end screen on pvc then a metal flex pipe. Thanks
  7. SmokeyTheBear

    SmokeyTheBear Minister of Fire

    Joined:
    Nov 10, 2008
    Messages:
    12,586
    Loc:
    Standish, ME
    No. Metal only.
  8. doublewide

    doublewide Member

    Joined:
    Jun 14, 2010
    Messages:
    119
    Loc:
    Eastern PA
    Thanks smokey that's what I thought.
  9. tbear853

    tbear853 New Member

    Joined:
    Jan 27, 2013
    Messages:
    16
    Loc:
    Shenandoah Valley of Virginia
    My old Vermont Castings Reliant pulled air in through a 2" pipe in back, I simply ran a piece of 2" car exhaust pipe outside through the corner of the metal square 12x12 wall kit, the pellet vent is in center. Outside it makes a couple turns with end pointed down and a small screen wire clamped over end. Connection fromn stove to air intake is with 2" ID hose and clamps, it does not get hot.
  10. SmokeyTheBear

    SmokeyTheBear Minister of Fire

    Joined:
    Nov 10, 2008
    Messages:
    12,586
    Loc:
    Standish, ME
    Under certain failure modes it can indeed get hot as it can become the stove's exhaust path for a short period of time.

    Installation requirements take into consideration more than normal operating conditions.
    Delta-T likes this.
  11. tbear853

    tbear853 New Member

    Joined:
    Jan 27, 2013
    Messages:
    16
    Loc:
    Shenandoah Valley of Virginia
    I guess you lost me there Smokey .... my manual states the use of outside air is optional, it is often (was then anyway) run using interior air for combustion intake? If it exhausted through it, that really would be a serious health and safety hazard if used without outside hook up.
    I'll have to investigate closely again. Might wrap the connector with some thin stainless steel.
  12. SmokeyTheBear

    SmokeyTheBear Minister of Fire

    Joined:
    Nov 10, 2008
    Messages:
    12,586
    Loc:
    Standish, ME
    It is a serious issue if you start getting exhaust out that air intake and that is the reason you have clearances and the requirement for a non combustible floor covering under the stove etc...

    Once you add a piece of any type of pipe to that air intake you merely are extending it to the outside of the house that extension must be non combustible.

    It is always a safety hazard to have exhaust being dumped into a room in a house.

    It is a matter the amount of bad stuff and the temperature of the bad stuff and for how long the bad stuff is being dumped into the room that determines if things are going to be fine or not.

    Without an OAK what gets dumped into the room expands in volume and cools off fairly fast. With an OAK it merely does that outside of the house and the only thing you have to worry about is being able to contain what is in the exhaust from starting a fire.

    If the OAK were to be made of plastic it can both melt or catch on fire.

    Once again in normal operation it would make no difference one way or the other what you made an OAK out of, but once you have an OAK it must be able to handle any reasonable failure which in this instance is reverse air flow.

    Hell in normal operation your stove's convection blower removes enough heat from the heat exchanger to keep it below the high limit temperature, so why is there a high limit on the stove? Same goes for that vacuum switch, or hopper lid switch, or door switch.

    Stoves have safeties some of those safeties are active safeties some are passive safeties your vent system from one end to the other (air intake to termination cap) is a safety system as well (most wouldn't think of it that way but it is) and it is very passive..
    P38X2 and Delta-T like this.
  13. Delta-T

    Delta-T Minister of Fire

    Joined:
    Feb 27, 2008
    Messages:
    3,125
    Loc:
    NH
    ^ like he said, but with a funny accent...==c
  14. Delta-T

    Delta-T Minister of Fire

    Joined:
    Feb 27, 2008
    Messages:
    3,125
    Loc:
    NH
    there must be some type of badge or something we can get you smokey...some people hit the nail on the head...you punch it in the face.
  15. tbear853

    tbear853 New Member

    Joined:
    Jan 27, 2013
    Messages:
    16
    Loc:
    Shenandoah Valley of Virginia
    I hear you Smokey .... I've had the stove going and had total power outages and then the fans stop and the fire just slowly but surely dies down .... but if the power comes on while there are embers it does come back up soon.
    I am trying to imagine a scenario where exhaust would come out the intake tube?

    Anyway, as a result of what you said earlier, I inspected my install as to air intake as it's been a few years since I have had the air intake apart. I have, as I said, 2" steel exhaust tubing for outside air and inside I have a short piece with 45 degree bend fitted to the stove with a wrap of thin stainless steel wrapped double already and then stainless steel worm clamps. I thought I had a heavy rubber sleeve, perhaps I used to? Anyway, stove's hot but intake is cold to touch.

    Come warmer weather this spring and she'll get a thorough going over and I'll look at maybe something new in the connections and some new "pellet flue".

    Thanks ............... :)
  16. SmokeyTheBear

    SmokeyTheBear Minister of Fire

    Joined:
    Nov 10, 2008
    Messages:
    12,586
    Loc:
    Standish, ME
    Anything that makes the air intake a better exhaust path than the exhaust vent, negative air pressure situations, suddenly plugged exhaust. Yes, it would be rare.

    The situations you picked were both things that an OAK helps in keeping the smoke going in the correct direction.
  17. doublewide

    doublewide Member

    Joined:
    Jun 14, 2010
    Messages:
    119
    Loc:
    Eastern PA
    Here is an example for you of smoke coming out the intake pipe. One time I lit my stove manually with a torch, I shut the door to the stove and apparently the flame died down due to pellets being fed on the small flame. Apparently, the flame died out and started smoltering due to the automatic pellet feeding. At this point, I was letting my dog in from outside. When I got back to the stove a minute later I could not see the burn pot due to all the smoke and it started pushing smoke out the intake (I do not have an OAK hooked up. I closed the OAK opened the door to the stove and a good puff of smoke got in the house. I relit the stove as fast as I could and all was fine. The moral of the story is when you are lighting a stove always stay there for the 10 minutes it takes to light and burn properly and use a metal OAK. Likewise, having an OAK would of prevented the house from getting smoke in it. Furthermore, if the stove would have lit under these unique conditions it would have most likely used the OAK to vent the gasses and would have became extremely hot.
  18. Hoot23

    Hoot23 Minister of Fire

    Joined:
    Mar 28, 2012
    Messages:
    869
    Loc:
    Alfred, Me
    Finally picked up the OAK and installed today. And while I was doing that, the wife and mother-in-law picked me up an iPad2 which I took this pic with. image.jpg
  19. CJ_starr

    CJ_starr New Member

    Joined:
    Feb 1, 2013
    Messages:
    18
    Loc:
    NH
    Looks good! An OAK and an iPad 2 all in one day? Great success!!! :)
  20. glenc0322

    glenc0322 Minister of Fire

    Joined:
    Dec 30, 2011
    Messages:
    605
    Loc:
    long Island NY
    An I pad 2 thats like 2 tons of pellets decisions decisions
  21. Hoot23

    Hoot23 Minister of Fire

    Joined:
    Mar 28, 2012
    Messages:
    869
    Loc:
    Alfred, Me
    Picked up some Vermont's while I was getting the OAK kit. A lot of money spent today.
  22. Dinger

    Dinger Member

    Joined:
    Nov 23, 2011
    Messages:
    140
    Loc:
    SW CO
    "Taking pictures with an iPad is the new fanny pack."

    I stole that. They are awesome machines though.
    Hoot23 likes this.
  23. movemaine

    movemaine Feeling the Heat

    Joined:
    Nov 28, 2011
    Messages:
    477
    Loc:
    Central Maine
    Any other places to buy a Harman Accentra OAK? and then what's the best chimney cap for an OAK?

    my vent pipe runs the full length of my chimney, and it's my understanding I can just run the oak up past the damper/insulation - that it doesn't need to run full length.
  24. Hoot23

    Hoot23 Minister of Fire

    Joined:
    Mar 28, 2012
    Messages:
    869
    Loc:
    Alfred, Me
    Not sure on that one.mi would think the oak has to run the full length. I think?
  25. tbear853

    tbear853 New Member

    Joined:
    Jan 27, 2013
    Messages:
    16
    Loc:
    Shenandoah Valley of Virginia
    Yeah, I've had some "fasle starts" as well .... and some were back when I did not have outside air for combustion, but I never had smoke out the intake. I have had the smoke come into the room when I opened the door to relight. I have gotten better about my starts..

Share This Page