Is this fresh air intake up to code?

Outside air has been a requirement in homes with fuel burning appliances(clothes dryer, furnace, water heater) in my area for almost 40 years.

Is OK really that far behind the times?:stuck_out_tongue:

Definitely a regional type of system. The difference in bin data between Iowa and Oklahoma is pretty substantial.

The only time that should be used is on a call for heat.