Intake and exhaust separation

[Richard Roshak]

Does anyone no the required separation between intake and exhaust for a 7 year old 90% Rheem gas heating unit.

[Eric Barker]

The distances can vary between manufacturers. But for your photo you'll be safe to say it isn't correct.

[Richard Abrams]

I think it is 3 feet on the same level and in your picture it is too close.:)

[Markus Keller]

Last time I looked it was a 12" offset. It looks like there aren't any screens on those 45's to keep the birds out. Yes it does happen.
I don't remember if it was Rheem or another manuf. but someone wanted a Tee on the combustion air not an L.