Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4848314 | Condensing furnace | — | 1989-07-18 |
| 4807588 | Water permeable heat exchanger for condensing furnace | Chester D. Ripka, Henry F. Keller | 1989-02-28 |
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4848314 | Condensing furnace | — | 1989-07-18 |
| 4807588 | Water permeable heat exchanger for condensing furnace | Chester D. Ripka, Henry F. Keller | 1989-02-28 |