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Harman Accentra Insert Outside Air Assembly, 1-00-674080

SKU 1-00-674080
MPN 1-00-674080
Only 4 Left In Stock
  • Extremely Durable
  • Ships FREE with orders over $199
  • 30-Day Hassle Free Returns!
  • 90 Day Warranty Included
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Frequently Bought Together


This outside air kit mounts to the intake on the back of the insert to provide a sealed docking point for a 3" intake air connection to be run up the chimney. This intake requires additional venting with proper Colinear 3x4 Stainless Termination in masonry applications or a colinear thimble for zero-clearance applications.

Note: The Accentra Insert was discontinued in 2012 and became the Accentra 52i, which uses a different outside air assembly. If you aren't sure which model you have, your model number is listed behind the right-side cast panel door.

Replacement For Part Number:
  • 1-00-674080

Click To See Compatible Models


Assembly Instructions For Harman Accentra Insert Outside Air Assembly, 1-00-674080

The pellet venting we sell is Dura-Vent Pellet Vent Pro. Pellet Vent Pro is a twist-lock pellet vent that has an integrated silicon seal within the vent. Simpson Dura-Vent, the pellet venting available in home stores like Home Depot and Lowe's (and we do not sell) is a lower grade pellet venting without the integrated silicon seal. THESE VENTING TYPES ARE MADE BY THE SAME MANUFACTURER BUT THEY CANNOT BE USED TOGETHER AND ARE NOT COMPATIBLE.

Guidelines For a Proper Installation:


  • Every pellet stove has an exhaust take-off. This is where the venting attached to the stove. The take-off determines the venting diameter and cannot be reduced. If your stove has a 4" diameter take-off, you cannot reduce down to 3" at the take-off or anywhere else in the venting configuration.

  • You must ALWAYS use an appliance adapter at the take-off. Appliance adapters in Pellet Vent Pro will end with "AD". Harman Pellet Stoves has its own adapter with "HAD" in the part number. Appliance adapter types: straight pipe, increases, and clean-out tees. All appliance adapters MUST be sealed with RTV silicone AND fastened to the take-off with screws.

  • All adjustable length venting pipes must be fastened with screws. When screws are used to fasten together venting pipe, the screws shall ONLY pierce the outer wall and not breach through the inner wall.


  • Venting seams (where two sections of venting twist-lock together) must never be concealed within a wall. Any seam that is in an enclosed or inaccessible space, must be screwed together prior to concealment.


  • Pellet Vent Pro has a 1" clearance to combustibles. Horizontal sections must be 7" above combustible floors unless shielding is used and 9" below combustibles unless shielding is used.


  • Horizontal venting rules: (1) No installation shall have more than 10 feet of horizontal venting; (2) All horizontal sections of venting must rise 1/4" over a foot for the entire span; (3) Horizontal sections of vent MUST be proceeded by followed by vertical sections at a rate of 2:1. For example: If your installation has 4 feet of horizontal travel, you must have at least 8 feet of vertical after the horizontal run.


  • A thimble MUST be used when passing through combustible walls.


  • An attic insulation shield MUST be used when passing vertically through an insulated space.


  • Venting configurations cannot have more than three 90° elbows or clean-out tees. Two 45° elbows equal one 90° elbow.


  • 3" Venting installations with more than 15 linear feet or require more than two 90° turns must be increased to 4" diameter.


  • Flexible liners can ONLY be used in CLASS A masonry chimney applications.


In addition, the following must be observed:

A. The clearance above grade must be a minimum of 12".

B. The clearance to a window or door that may be opened must be a minimum of 48" to the side, 48" below the window/door, 12" above the window/door. (with outside air installed, 9” to the side and below)

C. A 12" clearance to a permanently closed window is recommended to prevent condensation on the window.

D. The vertical clearance to a ventilated soffit located above the terminal within a horizontal distance of 2 feet (60 cm) from the center-line of the terminal must be a minimum of 18".

E. The clearance to an unventilated soffit must be a minimum of 12".

F. The clearance to an outside corner is 11" from the center of the pipe.

G. The clearance to an inside corner is 12".


H. A vent must not be installed within 3 feet (90 cm) above a gas meter/regulator assembly when measured from the horizontal center-line of the regulator.

I. The clearance to service regulator vent outlet must be a minimum of 6 feet.

J. The clearance to a non-mechanical air supply inlet to the building or the combustion air inlet to any other appliance must be a minimum of 48”.

K. The clearance to a mechanical air supply inlet must be a minimum of 10 feet. (with outside air installed, 6 feet)

L. The clearance above a paved sidewalk or a paved driveway located on public property must be a minimum of 7 feet.

M. The clearance under a veranda, porch, deck or balcony must be a minimum of 12 inches. (B. also)

NOTE: 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.

A vent shall not terminate directly above a sidewalk or paved driveway which is located between two single-family dwellings and serves both dwellings. Only permitted if veranda, porch, deck, or balcony is fully open on a minimum of 2 sides beneath the floor.


Be sure to use approved pellet vent pipe wall and ceiling pass- through fittings to go through combustible walls and ceilings. Be sure to use a starting collar to attach the venting system to the stove. The starting collar must be sealed to the vent pipe with high temp silicone caulking. 4" stainless steel flex vent piping is only allowed for use in masonry fireplaces and chimneys or factory built wood burning fireplaces with class A metal chimneys. Pellet venting pipe ( also known as PL vent) is constructed of two layers with air space between the layers. This air space acts as an insulator and reduces the outside surface temperature to allow a clearance to combustibles of only 3 inches. The sections of pipe lock together to form an air tight seal in most cases; however, in some cases a perfect seal is not achieved. For this reason and the fact that the Accentra Insert operates with a positive vent pressure, we specify that the joints also be sealed with clear silicone.


Unfortunately, sometimes products do not work like they are supposed to. We offer a 90 day warranty on manufacturer defects. Some manufacturers make this a very simple and easy process unfortunately others do not. Items must be used in accordance with the manufacturers guidelines to qualify for warranty replacement. Please be advised that warranty claims for these parts may take up to 4 weeks for processing, and customers must cover shipping.

Shipping Info

This Item Qualifies For Free Shipping!

When Will My Order Ship

All orders are typically processed within 24 hours of receiving payment and are shipped from us same day if placed before our shipping cutoff time (Monday - Friday: 1PM, Saturday: 10AM, Sunday: No Shipping), orders placed after our cutoff time are shipped the next morning.

How Does Free Shipping Work?

Most orders over $199 qualify for free shipping! Orders which ship for free are shipped with either USPS or UPS based on our discretion. If you are using a PO box, free shipping orders will always go USPS.

Is Expedited Shipping Available?

We offer both overnight and two day air shipping services for all orders placed within the Continental United States. For information on shipping cut-off times, go to our shipping page.

Do You Ship To Canada?

We ship to Canada! We estimate USPS to take 4-10 days once receiving your package from us. We do not offer expedited shipping of any kind to Canada. Please allow an extra 2-5 days for all shipments to Canada. Free shipping is not available to Canada.

Do You Ship To Alaska Or Hawii?

We ship to both Alaska and Hawaii! We do not offer next day or two day shipping to Alaska or Hawaii. Free shipping is not available to Alaska or Hawaii.

Do You Ship Outside The US Or Canada?

Unfortunately, at this time we do not offer international shipping other than to Canada.

Shipping Time Estimations

For information on shipping time estimations, see the Shipping Information & Transit Times on the shipping page.

Read More About Our Shipping Information


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