I’ve read justification on this but this is the first time seeing it in this configuration. The home was a condo with the furnace in the attic. The outside air intake was pulling air in from a roof vent and depositing it inside the return air plenum. No damper was present. The filter was upstream in the upstairs ceiling (so no filter at incoming fresh air). My concerns:
- Wouldn’t the unfiltered dust brought in from the outside negatively impact the air handler and create unhealthy indoor air?
- Wouldn’t this reduce the efficiency of the system, having to cool down hot, outside air in the summer, and heat cold winter air?
As you’ve probably heard on the news, we had a significant fire in San Diego yesterday. What if this condo were near the fire and the occupants were running the AC? The house would fill with smoke.