Clearance from exhaust to windows

Kent D._2

I am installing a direct-vent propane boiler, in the basement, that utilzes an intake/exhaust manifold. The manifold will be located between the first floor joists just above the top of foundation wall. What minimum distance is required, per ICBO, to the nearest window (on the first floor)? Also, what minimum distance is required from the manifold to the fresh air intake for a fireplace?

Thank you for the help.