I'm referring to the flap/vent design for routing in outside air. The problem with this vehicle platform is that the flap leaks a lot more outside air than most other vehicles. So just to put a number on it, let's say a typical car would only leak 5% outside air and 95% is recirculated cabin air. On the Innova, it's more like 20-30% outside air and the rest is recirculated air. Coming from driving a sedan for 7 years and driving the Innova, the result is very noticeable.
To illustrate (this took me a while to draw so bear with me), here are rough cross-sectional drawings of a part of the Innova's A/C. When the mode switch is set to Outside Air, a flap (blue part in the drawing) moves up to open up the outside air vent and at the same time, blocks the cabin air from recirculating. In this mode, the A/C is pulling in practically 100% outside air.
When you set it to Recirculate, the flap moves forward to block outside air and allow cabin air to flow. As you can see in the design, the tolerance between the flap and the outside air vent is too big and as a result, a significant amount of outside air is still getting in.... much, much higher than typical.
