before you assume new ones or are diverted by your personal interests. I have no idea how many other promises you have made, but in my case you can finish the ducts that were sold with your ICs. You also indicated that there would intake pipes of a diameter to match these ICs. You can get those done. If you don't intend to quickly produce the ducts and piping that support your ICs, you can offer to buy back any ICs you sold, including refund of all shipping costs.
And second, may I respectfully suggest that you avoid advertising and selling future products that you do not wholeheartedly intend to develop, support or produce in a timely manner.