| Number | Name | Date | Kind |
|---|---|---|---|
| 2941712 | Cook | Jun 1960 | |
| 3686452 | Opiela | Aug 1972 | |
| 4475569 | Foller | Oct 1984 | |
| 4482299 | Eulass | Nov 1984 | |
| 4748821 | Berenter | Jun 1988 | |
| 4856672 | Sullivan | Aug 1989 | |
| 5071027 | Sullivan | Dec 1991 | |
| 5074119 | Anderson | Dec 1991 |
| Number | Date | Country |
|---|---|---|
| 0268928 | Nov 1986 | JPX |
| Entry |
|---|
| Electric Power Research Institute, "Heat Pump Manual," EM-4110-SR, 1985. |
| Electric Power Research Institute, "Heat Pump Thermal Distribution Systems," CU-6962, vols. I and II, Aug. 1990. |