Number | Name | Date | Kind |
---|---|---|---|
2529154 | Hammond et al. | Nov 1950 | |
2749724 | Borgerd et al. | Jun 1956 | |
2860493 | Capps et al. | Nov 1958 | |
3247679 | Meckler | Apr 1966 | |
3957109 | Worthington | May 1976 | |
3965972 | Peterson | Jun 1976 | |
3996759 | Meckler | Dec 1976 | |
4012920 | Kirschbaum | Mar 1977 | |
4030312 | Wallin et al. | Jun 1977 | |
4037650 | Randall | Jul 1977 | |
4064867 | Schlesinger | Dec 1977 |
Entry |
---|
"Solar Heating with Heat Pump Auxiliary", PPG Catalog, Feb. 7, 1976. |