I've got a high efficiency Carrier 9200 furnace with two PVC pipes (intake and exhaust). The system works fine. The problem is the exhaust pipe elbow sits at about 3' off the ground and points directly at my car in the driveway. In cold weather this results in a fair bit of condensation forming on the side of the vehicle.
So I'm wondering if it's possible to raise the exhaust a few feet? Don't need a lot more, probably just another 2' higher. That'd be enough to let the warm air to blow over the vehicle instead of directly at it.
I'm wondering whether that would have any adverse impact on the exhaust operation of the furnace. Right now, inside the house the pipes extend up 5' from the side of the furnace, to the joists and over about 4' through the exterior wall. Once outside they extend up about 2.5' for the intake and 3' for the exhaust. The intake has an inverted U fitting and there's a 90 elbow on the exhaust. It looks like it'd be fairly simple to trim off the elbow, use a coupler and add a 2 feet more pipe with a new elbow. And maybe another bracket to secure it to the wall.
Are there limits on how high this exposed portion of the exhaust pipe can rise?