Tech Tip: Termination Vent Restrictors

in Tech Tips

Simplifying Termination Vent Restrictors

Did you know that most flame issues can be solved at the installation stage before the unit is even first fired up?

By planning out the vent run and then using this plan to install and set vent restrictors accordingly can eliminate the most common flame issues.

While every install is unique, knowledge of how a vertical heavy run vs a horizontal heavy vent run, along with quantities of elbows can assist in knowing which restrictor to use.

A common installer question is: “Why would I install a vent restrictor at the termination rather than at the fireplace itself?”

The main reason is that a restrictor placed in the firebox can lead to increased glass temperatures and risks glass failure. Additionally, if the restrictor is installed at the termination before constructing the vent system, then placing the termination restrictor is virtually as easy as installing a firebox restrictor.

The restriction may be too closed if:

  • The flame is excessively tall or ghosting
  • The flame is too still and candling

The restriction may be too open if:

  • The flame height is low
  • Flame has excessive movement

Divine, Phenom & DelRay Linear Series

Vertical Vent Restrictors

4″ / 7″ Venting
MVVR-8 8′ to 14′ Vertical Restriction
MVVR-15 15′ to 24′ Vertical Restriction
MVVR-15 25′ and up Vertical Restriction

5″ / 8″Venting
PVVR-8 8′ to 14′ Vertical Restriction
PVVR-15 15′ to 24′ Vertical Restriction
PVVR-25 25′ and up Vertical Restriction

Installation Instructions:

Remove the three screws that attach the termination cap to the termination (replace cap the same way it was removed).
Place the vent restriction in the flue section of the pipe and fold over the three strips at the proper height.
Replace the cap using the three screws.

Divine and Phenom Series

Horizontal Vent Restrictors

4″ / 7″ Venting
MHVR-8 8′ to 14′ Vertical Restriction
MHVR-15 15′ to 24′ Vertical Restriction
MHVR-15 25′ and up Vertical Restriction

5″ / 8″ Venting
PHVR-8 8′ to 14′ Vertical Restriction
PHVR-15 15′ to 24′ Vertical Restriction
PHVR-25 25′ and up Vertical Restriction

Installation Instructions:

Remove cap assembly by drilling out rivets.
Install restrictor plate as shown in drawing, attach plate.

Using four self tapping screws: ensure center location.

Re-install cap assembly with rivets or screws.

Commercial Quality

Professionals planning a custom residential or commercial fireplace project, please contact the Montigo sales rep in your area.