"1977, Kaiman Lee, Encyclopedia of Energy-Efficient Building Design: 391 Practical Case Studies - This [warm-air heated] house has a supplemental electric hot water heater and an oil furnace."
"1977, Kaiman Lee, Encyclopedia of Energy-Efficient Building Design: 391 Practical Case Studies - This [warm-air heated] house has a supplemental electric hot water heater and an oil furnace."