Harman P43 - venting question/concern

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.


New Member
Oct 18, 2021
NE Indiana
Hello all & thanks in advance for reading this and for any input/feedback provided. After much deliberation on woodstove/propane heat/pellet stove to supplement my heat pump I've decided on a Harman P43. It seems the Harman are heavily favored on the forum which led me to them to begin with. There are only three (to my knowledge) available in a 3 hour radius of me so today I ordered one from a dealer along with the venting. I will be doing a corner install in my basement at the bottom of the stairwell. It will face the family room this way but the heat should still rise up the stairs. The stairs are central in the home and I'm hoping the location will help distribute the heat better. I'm a newbie here (zero pellet stove experience) but a quick learn. I've been trying to pack in as much knowledge as I can in a short amount of time but due to supply issues I did want to make a decision quickly so I have some source of heat if my existing (20 year old heat pump) takes a crap or I lose power. I'm aware the pellet requires some power but I have a honda 2000 generator if it happens and one day I'd love to set it up with an inverter/battery backup.

The dealer was going to just sell me a duravent thimble for exhaust only but I was able to add on the harman thimble with the outdoor air intake for an additional $150. Initially I imagined doing a horizontal run from the stove to my exterior wall into the thimble. My concern with this is that it is only 10" off the ground (on center). I worry about snow in the winter and weeds/leaves in the other seasons. This has me considering doing a T, with a vertical run before exiting the house. However, that means I have to run that flexible line for the outdoor air intake higher up and potentially have to look at it on my interior wall (it feels like it would be ugly). Which leads me to reconsidering the duravent thimble with a t, then a vertical/horizontal run keeping the exhaust vent further off the ground on the exterior wall. If I do that I realize I'd have to then install a separate OAK kit lower to the ground. Any thoughts on which makes more sense or better in the long run? The horizontal run is appealing for cleaning the vent but maybe I'm overthinking this. I hope this makes sense. Thanks again
According to the Harman install manual, the exhaust must be a minimum of 12" above grade. Additionally,, "The clearance to vegetation and other exterior combustibles such as mulch is 36” as measured from the center of the outlet or cap. This 36” radius continues to grade."

So, depending on your circumstances, you should probably have a rise. You could certainly do the OAK and exhaust seperately and would probably be the cheapest solution. There is also venting made that has the OAK integrated around the outside of the exhaust pipe so visually it would look as if you only have and exhaust - it is just a larger total diameter. I'm unsure what it is called, but I believe it is fairly expensive. I'm sure others will chime in on that.
  • Like
Reactions: Washed-Up
My only input as a P43 owner with it installed on our "living" level, would be to move up to the P61, or the P68 if you have the extra for it, if it's not too late. It is in the room with the stairs to our 1/2 story cape cod, which stays acceptable.

I do not have an OAK or any vertical draft in the exhaust, but when it is in the single digits there is something left to be desired.
I have a P68 in the basement pointed at the stairs. It heats our kitchen and living room above it, and that's about it. I definitely would not want a smaller stove down there. If we owned this house, it would be in the living room, which would make tons more sense, but the homeowner did not want us cutting up the drywall to try to find the chimney he covered up years ago.

To answer your question more directly, my exhaust is about a foot off the ground (I didn't measure it). You do have to be careful with snow. Last year we got 22 inches in one storm, but thankfully (and not thinking about it) I left the stove on manual ignition (running constantly) all night long. The "waste" heat melted the snow as it fell in a huge arc around the termination, so it wasn't an issue.

Pellet stoves are forced draft stoves, meaning the fan has to be running or your house fills with smoke. If you have 3 feet of rise in your pipe, the book says there will be enough draft to get smoke out when your power goes out. If it happens while you're asleep and don't get your generator kicked on quickly, a direct vent with no rise will be smokey. If you lose power often, that will not be fun.
  • Like
Reactions: Washed-Up