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Author Topic: problem with furnace fresh air intake termination.clearance to dryer vent  (Read 1552 times)

Offline scbor

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Hi everyone.
Where should I terminate with furnace intake pipe?Please check the picture.
To the left of the pipe there is patio door, to the right furnace vent, water heater vent and dryer vent.Also, you can see BBQ copper pipe too.
Thank you in advance for your suggestion.

Offline Admin

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You would need 3' clearance from the furnace intake to the dryer vent.  What model of furnace is it?  If the manual allows horizontal separation you could just snorkel the intake vent over.  Some furnaces allow the intake and vent to be installed in different pressure zones, so you may want to relocate the intake vent to another side of the house.  It looks like your in a middle unit which could be problematic.

Don't forget to paint the BBQ fittings.

Offline scbor

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Thank you for your response.
The furnace model is Keeprite N9MSE.
This is a townhouse complex so I am limited to this wall only.

Offline scbor

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Can I simply go with fresh air intake straight up, maintaining 3` distance from dryer vent?

Offline Admin

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You can, but the exhaust vent must also snorkle up 12" above the intake vent, as shown in my attachment.

Also the 45 on the exhaust is for a 1 pipe install only, so it should be removed because you're using 2 pipe system.

According to Table 16 of the NP9SE manual, it doesn't look like you need to insulate the vents outside after you snorkel them up.

This furnace requires that both pipes be installed in the same pressure zone.

If the existing furnace has 1 pipe there must be a fresh air duct inside the mechanical room.  Your new furnace can also be installed with 1 pipe.  If you already have a fresh air supply I wouldn't bother installing the furnace intake pipe.

Offline scbor

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Thank you for your help.
I am finishing my basement so wanted to make mechanical room separate . There is one fresh air pipe that ends a couple of inches from the top of the furnace. But I was told that If I want to isolate furnace in small mech room I need to go out with the intake pipe.
This is a reason why I am doing all this.
But if you say there is no need I would rather live everything as it was before.
Thank you again.

Offline Porcupinepuffer

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Is the fresh air pipe about 4" in diameter? I'd just stick with that and have it within the required 1' vertical and 2' horizontal distance of the air inlet of the furnace. It would also serve as a dual fresh air by also providing for your water heater. You just need to occasionally check the screen outside to make sure it isn't getting blocked up.

Offline walker

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I would just snorkel the intake to the left to give 3' from the dryer exhaust.

Offline Porcupinepuffer

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Snorkeling to the left won't give him 1' minimum clearance to the ground. He'll be constantly shoveling snow out of the way underneath it every winter. Even less since they say 1' minimum from the expected level of snow accumulation.

That copper gas line also looks like 1/2" OD. Not the greatest for supplying the bigr BTU's that most decent sized BBQ's require. I hope it's a short connection inside.

Offline walker

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Looks like 1ft to me.

Offline Porcupinepuffer

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Looks like 1ft to me.

I see what you mean. I was looking at it as the existing elbow not being glue'd and turning it to go left to get 3'. But you mean going up and over. And it does look like it is glued by the inside view :coffee: