This question is asked the most, in many different ways. Yes, it is backwards and upside down compared to the majority of other Solar Air Heaters out there. That is why Okapi is a true innovation!
Please google/search these words: "moving warm air from ceiling to floor" and you will see there are numerous products for sale, blog-writings, articles and commentary from DIY enthusiasts who are cleverly reducing their heating bills simply by installing products such as a "Heatstick", "Blubox Thermal Fan" or other variations of these concepts.
When any home is heated traditionally, we almost always strive to heat from the bottom up: think installing your furnace or woodstove in your basement or bottom floor, "baseboard heaters", "in-floor heating", HVAC systems that pump warm air out from floor vents... The reason for this traditional approach to heating is because it is the most effective way to heat any space from the bottom up! Then, if you use something like a "Heatstick" or "Blubox Thermal Fan", which is simply a pipe with a fan that draws the warm air that pools at your ceiling (due to convection) down and pumps it back out at the floor level, you can reuse, conserve and store much more of the heat being produced to warm your building. This is technology and science in action: it works!
So, when we designed our Okapi Systems, we automatically thought, just like any other heating system, the solar-heat must come out near floor level to really be effective. And, also, we thought when designing Okapi, it would be doubly effective to draw the air down from the ceiling, through the heater and pump it back out at floor level, because just doing that alone, without additionally solar-heating the air, reduces heating bills already!
-"Very clever upside-down-the-box thinking", was how one of our customers put it!