| Clue | Source | Date |
|---|---|---|
| Like many air conditioning systems | Wall Street Journal | 02 Sep 2025 |
| Conveyed, as central air | Newsday | 03 Sep 2015 |
| Conveyed, as central air | ||
| Like many ventilation systems | ||
| Like many ventilation systems | ||
| Conveyed by pipes, as heat | ||
| Conveyed by pipes, as heat | ||
| Conveyed via a tube | ||
| Like homes with central air conditioning | ||
| Channeled |