DV Fireplace - Condensation on Firestop and Fresh Air Intake

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Bmg

New Member
Dec 21, 2021
1
Calgary
Hello All,

I've recently installed a Continental (Napoleon) DV Fireplace in my basement. When the temperature here in Calgary drops to -15C and below I get condensation and frost on the firestop and fresh air pipe inside my home just at the penetration. The firestop and venting is sealed inside the home and the termination cap is sealed outside. I've been running the pilot continuously but it is not enough heat to keep the firestop sleeve and outer pipe warm enough to prevent condensation. The exterior wall is insulated up to the firestop sleeve.

Venting and termination kit is - FTV47
Firestop sleeve is - VS47KT
Fireplace is - Continental CBL46

I wondered if this was going to become a problem once the temperature dipped this low. Basement temp is about 65F when the fireplace isn't running, humidity in the house is at 30%. The framing for the fireplace hasn't been closed in yet and am wondering once it is and sealed if the condensation will cease to be a problem as there shouldn't be much air movement back there. My neighbor has also recently had a new fireplace installed and has no condensation on his pipe but he ran hard pipe (I'm not sure if it's duravent or insulated piping). See pics attached, thanks for any help or insights.

20211215_070432.jpg 20211215_070417.jpg
 

Lennox65

Member
Jan 29, 2021
124
New Hampshire
Hello All,

I've recently installed a Continental (Napoleon) DV Fireplace in my basement. When the temperature here in Calgary drops to -15C and below I get condensation and frost on the firestop and fresh air pipe inside my home just at the penetration. The firestop and venting is sealed inside the home and the termination cap is sealed outside. I've been running the pilot continuously but it is not enough heat to keep the firestop sleeve and outer pipe warm enough to prevent condensation. The exterior wall is insulated up to the firestop sleeve.

Venting and termination kit is - FTV47
Firestop sleeve is - VS47KT
Fireplace is - Continental CBL46

I wondered if this was going to become a problem once the temperature dipped this low. Basement temp is about 65F when the fireplace isn't running, humidity in the house is at 30%. The framing for the fireplace hasn't been closed in yet and am wondering once it is and sealed if the condensation will cease to be a problem as there shouldn't be much air movement back there. My neighbor has also recently had a new fireplace installed and has no condensation on his pipe but he ran hard pipe (I'm not sure if it's duravent or insulated piping). See pics attached, thanks for any help or insights.

View attachment 288180 View attachment 288179
The design of direct vent fireplaces has an inner exhaust pipe and a larger outer pipe. The space between the two pipes is where the combustion air for the fireplace comes in from outside.
Even when everything is insulated and sealed properly, you are bringing cold air into the heated envelope of the house.