Wood Burning Insert

To start project, the very first thing is to measure the opening as shown in picture below

Key factors: front WidthHeight and Depth of opening.

The size of opening will determine how big the woodburning inset can go. Now you can focus on inserts that fit in measured size of the space. 




In some cases, the opening looks like picture shown below

The real meaningful opening dimension is the yellow area shown in picture above. The insert width and insert height are variables. In a given arched opening, if insert width increases, the insert height decreases or vice versa.

Most woodburning inserts don't have tapered back. After measuring the opening and choosing the insert, you have to double check to see if the back of insert will fit the opening.

measure opening size for wood burning insert installation

  1. Check the specs of insert you choose and find out the Minimum Opening Depth(same as Real Insert Depth in picture above) and Minimum Opening Width.

  2. From the Front Line measure into opening as much as Real Insert Depth, then draw a line. The width of this line (Back Width in picture above) has to be wider than the Minimum Opening Width required by the insert you choose. If this is the case, then your insert will certainly fit in the opening you have available.

The most important factors to be considered when buying wood burning insert

1. EPA (Environment Protection Agency) approved

  • All woodburning insert has to be EPA approved.

  • This is to certify that insert meets particulate emission guidelines.


2. Heating capacity

  •  It's related to the size of firebox. The bigger firebox, the more heat is generated.

  • The quality of log will largely affect the heat output.


3. Blower

  • Typically woodburning insert comes with blower 
  • Blower needs electricity to run and it's on 110 V


Factors related to installation:

1. 18" clearance in the front of insert

  • Woodburning insert requires 18" clearance in the front as picture shown below


2. Stainless steel chimney liner

  • By code, a stainless steel chimney liner must be installed inside masonry chimney with cap sits on top

  • Typically this chimney liner is 6" in diameter


3. Electricity supply

  • Typically woodburning insert comes with blower ( or called fan). 

  • It runs on electricity supplied through 110V electrical wire which has to be brought into opening.

Further factors to be considered

1. Modification of opening

  • To enlarge the opening is not recommended because it might affect the structure of opening and cause safety concern

  • To remove fire brick is not recommended because this opening has to be a functional masonry fireplace in first place.

2. Operation of woodburning insert

  • Keep air pressure in balance before light fire like open window for a few minutes.

  • Woodburning insert  consumes indoor oxygen while in use. This easily creates negative air pressure that can propel smoke into the house.

  • At the beginning of burning, chimney is not hot therefore fume doesn't have strong momentum to rise. Negative air pressure will create back draft that brings some smoke into the room. To deter this, a flaming log or torch can be held up the chimney in order to create an updraft and draw smoke out of the home while keeping window open for a while. Once chimney is hot then you can close the window.

3. Inspection from house insurance

  • In order to pass the inspection performed by house insurance company, woodburning insert must be EPA approved

  • Installation of woodburning insert has to be performed by WETT certified installer.