I would pass on the intake for now and see how it works without it. This is what I opted for last summer on my Harman P61A and it works like a champ without it. You can always install afterwards if you need to.

I would GET the intake. I have one and have no problems ( apx 4' long) I have disconnected it just to see what, if any, difference it made and found that with it disconnected the stove ran more ( and a little more fuel) to bring the house up to temp. I assume thats because it has the fan rapidly sucking the already heated air back out of the room to burn then exhaust outside. So if its pulling room air then cold air must also be pulled into the house through cracks to replace that air. I dont really know the tech facts, I just assume thats the reason, but I did hook it back up and kept it that way.

from the 70's up through the early 90's home construction made significant leaps and bounds. In the 70's if you took all the air leaks in a home and added them together you would end up with approx. a 3' diameter hole in your wall! Todays construction however is so tight if added all the leaks it would amount to approx. a 3" diameter hole BIG difference. Also in the envelope of the home you have all these appliances taking air out of the home. Dryers, ventahoods, CH/A, and yes even the fireplace just to name a few and nothing is bringing air in so eventually you end up with a negative preassure in the home or a vaccumm if you will and the home will take a breath where ever it can. Because of this hearth designers and manufacturers have come up with outside combustion air kits to offset the negative preassure sometimes its not enough to overcome it but does help in the efficency if the home is really tight. Hope this information aids you in your querry

I am also adding a pellet stove in the near future (Accentra - it's on order) - I decided it made more sense to add the outside air kit than not - the way I read it, an intake air pipe (3") is added beside the flue to a point just above the fiberglass packing on the top side of the shutter assembly - which leads me to wonder whether they seal the flue at the top of the chimney - I assume not. I have a 2 story house and I hope the length of the flue will not be a concern.

I installed a new Harman Accentra Pellet Insert. The
draft setting? Stove seems to be working well, good heat and a bag a day. The dealer will charge 150.00 to test the draft is it worth it. The little white screw only turns 180 deg, the factory setting is on high, then I've read it is self adjusting. Any thoughts???