I bought a house with an HRV (Heat Recovery Ventilation). The air intake for it is in a closed compartment under a staircase outside the house, so any air going in first has to go through small gaps between the boards of the stairs. I doubt the pressure drop is significant, but this compartment gets rain, and it is dirty and moldy, and the only air circulation in it is the air getting pulled into the HRV and then into the house. Sure the filter does its thing, but still. The outlet is on the side of the house in a good clearing that should provide clean air.
I'm fairly sure I could swap the intake/exhaust by switching two ducts on the top of the HRV. Would this be better than the current setup? It seems like under the stairs would be a fine place to exhaust an HRV, but not a good air source. Am I missing something? I'm wondering if this was the intended configuration and someone made a mistake when installing it.