Short vertical vent run

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New Member
Oct 30, 2021
South Eastern Pennsylvania
Im getting ready to install a used Harman P61A I just purchased and I have a question about the exhaust pipe run. The manual for Harman recommends at least 5 foot vertical run and the Duravent kit recommends a 3 foot vertical run. I’m replacing a direct vent gas fireplace and would prefer to use the existing hole if I can. The hole is about 3 foot high and the vertical run will probably be slightly less than 3 feet since the clean out and vertical run will be inside. Do you think this will be a problem or should I be cutting a new hole? Thanks!


Minister of Fire
Oct 31, 2014
South Central NH
Vertical run is a suggestion. It will aid in evacuating smoke in case of a power outage. I use one of the UPS's reccommended in my mannual for my stoves . When the stove detects it is running off the battery, it will start the shut down process pulsing the exhaust blower to evacuate smoke while not draining the battery to fast. Works fine for me.
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